Commit Graph

3329 Commits

Author SHA1 Message Date
Simon Pilgrim 4039dbea77 Fix unused variable warning.
llvm-svn: 324605
2018-02-08 14:24:26 +00:00
Simon Pilgrim 0b9f3912ce [InstCombine] Improve mul(x, pow2) -> shl combine for vector constants
Refactor getLogBase2Vector into getLogBase2 to accept all scalars/vectors. Generalize from ConstantDataVector to support all constant vectors.

llvm-svn: 324603
2018-02-08 14:10:01 +00:00
Sanjay Patel 49aafec2e6 [InstCombine] don't try to evaluate instructions with >1 use (revert r324014)
This example causes a compile-time explosion:

define i16 @foo(i16 %in) {
  %x = zext i16 %in to i32
  %a1 = mul i32 %x, %x
  %a2 = mul i32 %a1, %a1
  %a3 = mul i32 %a2, %a2
  %a4 = mul i32 %a3, %a3
  %a5 = mul i32 %a4, %a4
  %a6 = mul i32 %a5, %a5
  %a7 = mul i32 %a6, %a6
  %a8 = mul i32 %a7, %a7
  %a9 = mul i32 %a8, %a8
  %a10 = mul i32 %a9, %a9
  %a11 = mul i32 %a10, %a10
  %a12 = mul i32 %a11, %a11
  %a13 = mul i32 %a12, %a12
  %a14 = mul i32 %a13, %a13
  %a15 = mul i32 %a14, %a14
  %a16 = mul i32 %a15, %a15
  %a17 = mul i32 %a16, %a16
  %a18 = mul i32 %a17, %a17
  %a19 = mul i32 %a18, %a18
  %a20 = mul i32 %a19, %a19
  %a21 = mul i32 %a20, %a20
  %a22 = mul i32 %a21, %a21
  %a23 = mul i32 %a22, %a22
  %a24 = mul i32 %a23, %a23
  %T = trunc i32 %a24 to i16
  ret i16 %T
}

 

llvm-svn: 324276
2018-02-05 21:50:32 +00:00
Sanjay Patel e9a153f414 [InstCombine] add unsigned saturation subtraction canonicalizations
This is the instcombine part of unsigned saturation canonicalization.
Backend patches already commited: 
https://reviews.llvm.org/D37510
https://reviews.llvm.org/D37534

It converts unsigned saturated subtraction patterns to forms recognized 
by the backend:
(a > b) ? a - b : 0 -> ((a > b) ? a : b) - b)
(b < a) ? a - b : 0 -> ((a > b) ? a : b) - b)
(b > a) ? 0 : a - b -> ((a > b) ? a : b) - b)
(a < b) ? 0 : a - b -> ((a > b) ? a : b) - b)
((a > b) ? b - a : 0) -> - ((a > b) ? a : b) - b)
((b < a) ? b - a : 0) -> - ((a > b) ? a : b) - b)
((b > a) ? 0 : b - a) -> - ((a > b) ? a : b) - b)
((a < b) ? 0 : b - a) -> - ((a > b) ? a : b) - b)

Patch by Yulia Koval!

Differential Revision: https://reviews.llvm.org/D41480

llvm-svn: 324255
2018-02-05 17:53:29 +00:00
Sanjay Patel 2329fcd293 [InstCombine] only allow narrow/wide evaluation of values with >1 use if that user is a binop
There was a logic hole in D42739 / rL324014 because we're not accounting for select and phi
instructions that might have repeated operands. This is likely a source of an infinite loop.
I haven't manufactured a test case to prove that, but it should be safe to speculatively limit
this transform to binops while we try to create that test.

llvm-svn: 324252
2018-02-05 17:16:50 +00:00
David Green 7174023f57 [InstCombine] Allow common type conversions to i8/i16/i32
This, in instcombine, allows conversions to i8/i16/i32 (very
common cases) even if the resulting type is not legal according
to the data layout. This can often open up extra combine
opportunities.

Differential Revision: https://reviews.llvm.org/D42424

llvm-svn: 324174
2018-02-03 16:51:03 +00:00
Daniel Neilson 38af2eed51 [InstCombine] Use getDestAlignment in SimplifyMemSet (NFC)
Summary:
Small NFC change to change the name of the function used getting and setting
the alignment of a memset.

llvm-svn: 324148
2018-02-02 22:03:03 +00:00
Sanjay Patel 1ea8697cdf [InstCombine] simplify logic for swapMayExposeCSEOpportunities; NFCI
llvm-svn: 324122
2018-02-02 19:08:12 +00:00
Sanjay Patel 4ccae1cb2b [InstCombine] fix typos, formatting; NFC
llvm-svn: 324118
2018-02-02 18:39:05 +00:00
Sanjay Patel 3343fcef86 [InstCombine] allow multi-use values in canEvaluate* if all uses are in 1 inst
This is the enhancement suggested in D42536 to fix a shortcoming in 
regular InstCombine's canEvaluate* functionality.
When we have multiple uses of a value, but they're all in one instruction, we can 
allow that expression to be narrowed or widened for the same cost as a single-use 
value.

AFAICT, this can only matter for multiply: sub/and/or/xor/select would be simplified 
away if the operands are the same value; add becomes shl; shifts with a variable shift 
amount aren't handled.

Differential Revision: https://reviews.llvm.org/D42739

llvm-svn: 324014
2018-02-01 21:55:53 +00:00
David Green 184df0c35d Revert commit rL323951
Looks like it's causing timeouts out on at least ppc64le
buildbots.

llvm-svn: 323959
2018-02-01 13:05:25 +00:00
David Green e11f0545db [InstCombine] Allow common type conversions to i8/i16/i32
This, in instcombine, allows conversions to i8/i16/i32 (very
common cases) even if the resulting type is not legal according
to the data layout. This can often open up extra combine
opportunities.

Differential Revision: https://reviews.llvm.org/D42424

llvm-svn: 323951
2018-02-01 11:06:18 +00:00
Marek Olsak 13e4741275 AMDGPU: Add intrinsics llvm.amdgcn.cvt.{pknorm.i16, pknorm.u16, pk.i16, pk.u16}
Reviewers: arsenm, nhaehnle

Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye

Differential Revision: https://reviews.llvm.org/D41663

llvm-svn: 323908
2018-01-31 20:18:04 +00:00
Sanjay Patel 1b66deea16 [InstCombine] reduce code duplication for canEvaluate* functions; NFCI
We'd have to make the change suggested in D42536 3x otherwise. 

llvm-svn: 323877
2018-01-31 14:55:53 +00:00
Vedant Kumar e48597a50e [InstCombine] Preserve debug values for eliminable casts
A cast from A to B is eliminable if its result is casted to C, and if
the pair of casts could just be expressed as a single cast. E.g here,
%c1 is eliminable:

  %c1 = zext i16 %A to i32
  %c2 = sext i32 %c1 to i64

InstCombine optimizes away eliminable casts. This patch teaches it to
insert a dbg.value intrinsic pointing to the final result, so that local
variables pointing to the eliminable result are preserved.

Differential Revision: https://reviews.llvm.org/D42566

llvm-svn: 323570
2018-01-26 22:02:52 +00:00
Sanjay Patel 1d68112c4b [InstCombine] narrow masked zexted binops (PR35792)
This is guarded by shouldChangeType(), so the tests show that
we don't do the fold if the narrower type is not legal. Note
that there is a proposal (D42424) that would change the results
for the specific cases shown in these tests. That difference is
also discussed in PR35792:
https://bugs.llvm.org/show_bug.cgi?id=35792

Alive proofs for the cases handled here as well as the bitwise 
logic binops that we should already do better on:
https://rise4fun.com/Alive/c97
https://rise4fun.com/Alive/Lc5E
https://rise4fun.com/Alive/kdf

llvm-svn: 323437
2018-01-25 16:34:36 +00:00
Sanjay Patel 9530f18864 [InstCombine] (X << Y) / X -> 1 << Y
...when the shift is known to not overflow with the matching
signed-ness of the division.

This closes an optimization gap caused by canonicalizing mul
by power-of-2 to shl as shown in PR35709:
https://bugs.llvm.org/show_bug.cgi?id=35709

Patch by Anton Bikineev!

Differential Revision: https://reviews.llvm.org/D42032

llvm-svn: 323068
2018-01-21 16:14:51 +00:00
Daniel Neilson 1e68724d24 Remove alignment argument from memcpy/memmove/memset in favour of alignment attributes (Step 1)
Summary:
 This is a resurrection of work first proposed and discussed in Aug 2015:
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
and initially landed (but then backed out) in Nov 2015:
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

 The @llvm.memcpy/memmove/memset intrinsics currently have an explicit argument
which is required to be a constant integer. It represents the alignment of the
dest (and source), and so must be the minimum of the actual alignment of the
two.

 This change is the first in a series that allows source and dest to each
have their own alignments by using the alignment attribute on their arguments.

 In this change we:
1) Remove the alignment argument.
2) Add alignment attributes to the source & dest arguments. We, temporarily,
   require that the alignments for source & dest be equal.

 For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 100, i32 4, i1 false)
will now read
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %dest, i8* align 4 %src, i32 100, i1 false)

 Downstream users may have to update their lit tests that check for
@llvm.memcpy/memmove/memset call/declaration patterns. The following extended sed script
may help with updating the majority of your tests, but it does not catch all possible
patterns so some manual checking and updating will be required.

s~declare void @llvm\.mem(set|cpy|move)\.p([^(]*)\((.*), i32, i1\)~declare void @llvm.mem\1.p\2(\3, i1)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* \3, i8 \4, i8 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* \3, i8 \4, i16 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* \3, i8 \4, i32 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* \3, i8 \4, i64 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* \3, i8 \4, i128 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* align \6 \3, i8 \4, i8 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* align \6 \3, i8 \4, i16 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* align \6 \3, i8 \4, i32 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* align \6 \3, i8 \4, i64 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* align \6 \3, i8 \4, i128 \5, i1 \7)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* \4, i8\5* \6, i8 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* \4, i8\5* \6, i16 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* \4, i8\5* \6, i32 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* \4, i8\5* \6, i64 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* \4, i8\5* \6, i128 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* align \8 \4, i8\5* align \8 \6, i8 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* align \8 \4, i8\5* align \8 \6, i16 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* align \8 \4, i8\5* align \8 \6, i32 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* align \8 \4, i8\5* align \8 \6, i64 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* align \8 \4, i8\5* align \8 \6, i128 \7, i1 \9)~g

 The remaining changes in the series will:
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
   source and dest alignments.
Step 3) Update Clang to use the new IRBuilder API.
Step 4) Update Polly to use the new IRBuilder API.
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
        and those that use use MemIntrinsicInst::[get|set]Alignment() to use
        getDestAlignment() and getSourceAlignment() instead.
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
        MemIntrinsicInst::[get|set]Alignment() methods.

Reviewers: pete, hfinkel, lhames, reames, bollu

Reviewed By: reames

Subscribers: niosHD, reames, jholewinski, qcolombet, jfb, sanjoy, arsenm, dschuff, dylanmckay, mehdi_amini, sdardis, nemanjai, david2050, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, llvm-commits

Differential Revision: https://reviews.llvm.org/D41675

llvm-svn: 322965
2018-01-19 17:13:12 +00:00
John Brawn 2867bd72c0 [InstCombine] Make foldSelectOpOp able to handle two-operand getelementptr
Three (or more) operand getelementptrs could plausibly also be handled, but
handling only two-operand fits in easily with the existing BinaryOperator
handling.

Differential Revision: https://reviews.llvm.org/D39958

llvm-svn: 322930
2018-01-19 10:05:15 +00:00
Sanjay Patel aa766efd09 [InstCombine] fix demanded-bits propagation for zext/trunc
I was comparing the demanded-bits implementations between InstCombine
and TargetLowering as part of investigating questions in D42088 and
noticed that this was wrong in IR. We were losing all of the prior
known bits when we got back to the 'zext'.

llvm-svn: 322662
2018-01-17 14:39:28 +00:00
Daniel Neilson 2409d24201 [NFC] Change MemIntrinsicInst::setAlignment() to take an unsigned instead of a Constant
Summary:
 In preparation for https://reviews.llvm.org/D41675 this NFC changes this
prototype of MemIntrinsicInst::setAlignment() to accept an unsigned instead
of a Constant.

llvm-svn: 322403
2018-01-12 21:33:37 +00:00
Benjamin Kramer 738e6e7cb0 [InstCombine] Apply the fix from r322284 for sin / cos -> tan too
llvm-svn: 322285
2018-01-11 15:33:21 +00:00
Benjamin Kramer 44993ede60 [InstCombine] For cos/sin -> tan copy attributes from cos instead of the
parent function

Ideally we should merge the attributes from the functions somehow, but
this is obviously an improvement over taking random attributes from the
caller which will trip up the verifier if they're nonsensical for an
unary intrinsic call.

llvm-svn: 322284
2018-01-11 15:19:02 +00:00
Dmitry Venikov e5fbf591a7 [InstCombine] Missed optimization in math expression: sin(x) / cos(x) => tan(x)
Summary: This patch enables folding sin(x) / cos(x) -> tan(x), cos(x) / sin(x) -> 1 / tan(x) under -ffast-math flag

Reviewers: hfinkel, spatel

Reviewed By: spatel

Subscribers: andrew.w.kaylor, efriedma, scanon, llvm-commits

Differential Revision: https://reviews.llvm.org/D41286

llvm-svn: 322255
2018-01-11 06:33:00 +00:00
Sanjay Patel 6fb1357c35 [InstCombine] weaken assertions for icmp folds (PR35846)
Because of potential UB (known bits conflicts with an llvm.assume),
we have to check rather than assert here because InstSimplify doesn't
kill the compare:
https://bugs.llvm.org/show_bug.cgi?id=35846

llvm-svn: 322104
2018-01-09 18:56:03 +00:00
Simon Pilgrim 5d909be91b [InstCombine] Check for out of range ashr values using APInt before calling getZExtValue
Reduced from oss-fuzz #5032 test case

llvm-svn: 322078
2018-01-09 14:23:46 +00:00
Sanjay Patel 31b4b76f99 [InstCombine] fold min/max tree with common operand (PR35717)
There is precedence for factorization transforms in instcombine for FP ops with fast-math. 
We also have similar logic in foldSPFofSPF().

It would take more work to add this to reassociate because that's specialized for binops, 
and min/max are not binops (or even single instructions). Also, I don't have evidence that 
larger min/max trees than this exist in real code, but if we find that's true, we might
want to reorganize where/how we do this optimization.

In the motivating example from https://bugs.llvm.org/show_bug.cgi?id=35717 , we have:

int test(int xc, int xm, int xy) {
  int xk;
  if (xc < xm)
    xk = xc < xy ? xc : xy;
  else
    xk = xm < xy ? xm : xy;
  return xk;
}

This patch solves that problem because we recognize more min/max patterns after rL321672

https://rise4fun.com/Alive/Qjne
https://rise4fun.com/Alive/3yg

Differential Revision: https://reviews.llvm.org/D41603

llvm-svn: 321998
2018-01-08 15:05:34 +00:00
Sanjay Patel 26a6fcde83 [InstCombine] relax use constraint for min/max (~a, ~b) --> ~min/max(a, b)
In the minimal case, this won't remove instructions, but it still improves
uses of existing values.

In the motivating example from PR35834, it does remove instructions, and
sets that case up to be optimized by something like D41603:
https://reviews.llvm.org/D41603

llvm-svn: 321936
2018-01-06 17:34:22 +00:00
Sanjay Patel 5b6aacf2c1 [InstCombine] add folds for min(~a, b) --> ~max(a, b)
Besides the bug of omitting the inverse transform of max(~a, ~b) --> ~min(a, b),
the use checking and operand creation were off. We were potentially creating 
repeated identical instructions of existing values. This led to infinite
looping after I added the extra folds.

By using the simpler m_Not matcher and not creating new 'not' ops for a and b,
we avoid that problem. It's possible that not using IsFreeToInvert() here is
more limiting than the simpler matcher, but there are no tests for anything
more exotic. It's also possible that we should relax the use checking further
to handle a case like PR35834:
https://bugs.llvm.org/show_bug.cgi?id=35834
...but we can make that a follow-up if it is needed. 

llvm-svn: 321882
2018-01-05 19:01:17 +00:00
Sanjay Patel c63f9014d6 [InstCombine] safely create a constant of the right type (PR35794)
llvm-svn: 321801
2018-01-04 14:31:56 +00:00
Simon Pilgrim 3bf2d64589 [InstCombine] Check for out of range shift values using APInt before calling getZExtValue
Reduced from oss-fuzz #4871 test case

llvm-svn: 321748
2018-01-03 18:28:20 +00:00
Dmitry Venikov a58d8deb3a [InstCombine] Missed optimization in math expression: squashing sqrt functions
Summary: This patch enables folding under -ffast-math flag sqrt(a) * sqrt(b) -> sqrt(a*b)

Reviewers: hfinkel, spatel, davide

Reviewed By: spatel, davide

Subscribers: davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D41322

llvm-svn: 321637
2018-01-02 05:58:11 +00:00
Simon Pilgrim 472689a159 [InstCombine] Check for isa<Instruction> before using cast<>
Protects against casts from constexpr etc.

Reduced from oss-fuzz #4788 test case

llvm-svn: 321515
2017-12-28 09:35:35 +00:00
Simon Pilgrim e7d032f1d8 [InstCombine] Gracefully handle out of range extractelement indices
InstSimplify is responsible for handling these, but we shouldn't just assert here.

Reduced from oss-fuzz #4808 test case

llvm-svn: 321489
2017-12-27 12:00:18 +00:00
Philip Reames cd13a66381 [instcombine] add powi(x, 2) -> x * x
llvm-svn: 321468
2017-12-27 01:30:12 +00:00
Philip Reames 5000ba69d7 Sink a couple of transforms from instcombine into instsimplify.
llvm-svn: 321467
2017-12-27 01:14:30 +00:00
Philip Reames 7a6db4fc4f [NFC] Extract out a helper function for SimplifyCall(CS, Q)
This simplifies code, but the real motivation is that it lets me clean up some downstream code.

llvm-svn: 321466
2017-12-27 00:16:12 +00:00
Sanjay Patel 14adbacd8a [InstCombine] fix miscompile of frem with 0.0 operand (PR34870)
We might want to select NAN here or do this transform with fast-math,
but this should at least fix the miscompile.

llvm-svn: 321461
2017-12-26 22:12:20 +00:00
Florian Hahn 012c8f97b2 [InstCombine] Add debug location to new caller.
Reviewers: rnk, aprantl, majnemer

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D414

llvm-svn: 321191
2017-12-20 17:16:59 +00:00
Sanjay Patel 5a0cdac174 [InstCombine] canonicalize shifty abs(): ashr+add+xor --> cmp+neg+sel
We want to do this for 2 reasons:
1. Value tracking does not recognize the ashr variant, so it would fail to match for cases like D39766.
2. DAGCombiner does better at producing optimal codegen when we have the cmp+sel pattern.

More detail about what happens in the backend:
1. DAGCombiner has a generic transform for all targets to convert the scalar cmp+sel variant of abs 
   into the shift variant. That is the opposite of this IR canonicalization.
2. DAGCombiner has a generic transform for all targets to convert the vector cmp+sel variant of abs 
   into either an ABS node or the shift variant. That is again the opposite of this IR canonicalization.
3. DAGCombiner has a generic transform for all targets to convert the exact shift variants produced by #1 or #2
   into an ISD::ABS node. Note: It would be an efficiency improvement if we had #1 go directly to an ABS node 
   when that's legal/custom.
4. The pattern matching above is incomplete, so it is possible to escape the intended/optimal codegen in a 
   variety of ways.
   a. For #2, the vector path is missing the case for setlt with a '1' constant.
   b. For #3, we are missing a match for commuted versions of the shift variants.
5. Therefore, this IR canonicalization can only help get us to the optimal codegen. The version of cmp+sel 
   produced by this patch will be recognized in the DAG and converted to an ABS node when possible or the 
   shift sequence when not.
6. In the following examples with this patch applied, we may get conditional moves rather than the shift 
   produced by the generic DAGCombiner transforms. The conditional move is created using a target-specific 
   decision for any given target. Whether it is optimal or not for a particular subtarget may be up for debate.

define i32 @abs_shifty(i32 %x) {
  %signbit = ashr i32 %x, 31 
  %add = add i32 %signbit, %x  
  %abs = xor i32 %signbit, %add 
  ret i32 %abs
}

define i32 @abs_cmpsubsel(i32 %x) {
  %cmp = icmp slt i32 %x, zeroinitializer
  %sub = sub i32 zeroinitializer, %x
  %abs = select i1 %cmp, i32 %sub, i32 %x
  ret i32 %abs
}

define <4 x i32> @abs_shifty_vec(<4 x i32> %x) {
  %signbit = ashr <4 x i32> %x, <i32 31, i32 31, i32 31, i32 31> 
  %add = add <4 x i32> %signbit, %x  
  %abs = xor <4 x i32> %signbit, %add 
  ret <4 x i32> %abs
}

define <4 x i32> @abs_cmpsubsel_vec(<4 x i32> %x) {
  %cmp = icmp slt <4 x i32> %x, zeroinitializer
  %sub = sub <4 x i32> zeroinitializer, %x
  %abs = select <4 x i1> %cmp, <4 x i32> %sub, <4 x i32> %x
  ret <4 x i32> %abs
}

> $ ./opt -instcombine shiftyabs.ll -S | ./llc -o - -mtriple=x86_64 -mattr=avx 
> abs_shifty:
> 	movl	%edi, %eax
> 	negl	%eax
> 	cmovll	%edi, %eax
> 	retq
> 
> abs_cmpsubsel:
> 	movl	%edi, %eax
> 	negl	%eax
> 	cmovll	%edi, %eax
> 	retq
> 
> abs_shifty_vec:
> 	vpabsd	%xmm0, %xmm0
> 	retq
> 
> abs_cmpsubsel_vec:
> 	vpabsd	%xmm0, %xmm0
> 	retq
> 
> $ ./opt -instcombine shiftyabs.ll -S | ./llc -o - -mtriple=aarch64
> abs_shifty:
> 	cmp	w0, #0                  // =0
> 	cneg	w0, w0, mi
> 	ret
> 
> abs_cmpsubsel: 
> 	cmp	w0, #0                  // =0
> 	cneg	w0, w0, mi
> 	ret
>                                        
> abs_shifty_vec: 
> 	abs	v0.4s, v0.4s
> 	ret
> 
> abs_cmpsubsel_vec: 
> 	abs	v0.4s, v0.4s
> 	ret
> 
> $ ./opt -instcombine shiftyabs.ll -S | ./llc -o - -mtriple=powerpc64le 
> abs_shifty:  
> 	srawi 4, 3, 31
> 	add 3, 3, 4
> 	xor 3, 3, 4
> 	blr
> 
> abs_cmpsubsel:
> 	srawi 4, 3, 31
> 	add 3, 3, 4
> 	xor 3, 3, 4
> 	blr
> 
> abs_shifty_vec:   
> 	vspltisw 3, -16
> 	vspltisw 4, 15
> 	vsubuwm 3, 4, 3
> 	vsraw 3, 2, 3
> 	vadduwm 2, 2, 3
> 	xxlxor 34, 34, 35
> 	blr
> 
> abs_cmpsubsel_vec: 
> 	vspltisw 3, -16
> 	vspltisw 4, 15
> 	vsubuwm 3, 4, 3
> 	vsraw 3, 2, 3
> 	vadduwm 2, 2, 3
> 	xxlxor 34, 34, 35
> 	blr
>

Differential Revision: https://reviews.llvm.org/D40984

llvm-svn: 320921
2017-12-16 16:41:17 +00:00
Fedor Sergeev 83bcc68afa [PM][InstCombine] fixing omission of AliasAnalysis in new-pass-manager's version of InstCombine
Summary:
Passing AliasAnalysis results instead of nullptr appears to work just fine.
A couple new-pass-manager tests updated to align with new order of analyses.

Reviewers: chandlerc, spatel, craig.topper

Reviewed By: chandlerc

Subscribers: mehdi_amini, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D41203

llvm-svn: 320687
2017-12-14 10:36:31 +00:00
Michael Zolotukhin 6af4f232b5 Remove redundant includes from lib/Transforms.
llvm-svn: 320628
2017-12-13 21:31:01 +00:00
Igor Laevsky e0edb66475 Reintroduce r320049, r320014 and r319894.
OpenGL issues should be fixed by now.

llvm-svn: 320568
2017-12-13 11:21:18 +00:00
Alexey Bataev 83c15b1363 [InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast.
Summary:
If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
&V2)))), bitcast)`, but the load is used in other instructions, it leads
to looping in InstCombiner. Patch adds additional check that all users
of the load instructions are stores and then replaces all uses of load
instruction by the new one with new type.

Reviewers: RKSimon, spatel, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320525
2017-12-12 20:28:46 +00:00
Alexey Bataev fa0a76dbcc Revert "[InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast."
This reverts commit r320510 - again sanitizers bbots.

llvm-svn: 320513
2017-12-12 19:12:34 +00:00
Alexey Bataev 195c97e220 [InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast.
Summary:
If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
&V2)))), bitcast)`, but the load is used in other instructions, it leads
to looping in InstCombiner. Patch adds additional check that all users
of the load instructions are stores and then replaces all uses of load
instruction by the new one with new type.

Reviewers: RKSimon, spatel, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320510
2017-12-12 18:47:00 +00:00
Alexey Bataev 6132a50d2a Revert "[InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast."
This reverts commit r320499 again to resolve the problem with the
sanitizers bbots.

llvm-svn: 320501
2017-12-12 17:35:29 +00:00
Alexey Bataev ca4c9a5246 [InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast.
Summary:
If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
&V2)))), bitcast)`, but the load is used in other instructions, it leads
to looping in InstCombiner. Patch adds additional check that all users
of the load instructions are stores and then replaces all uses of load
instruction by the new one with new type.

Reviewers: RKSimon, spatel, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320499
2017-12-12 17:19:15 +00:00
Alexey Bataev d19dbe6791 Revert "[InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast."
This reverts commit r320496 to solve the problems with sanitizer
buildbots.

llvm-svn: 320498
2017-12-12 17:08:48 +00:00
Alexey Bataev d0c3aeb200 [InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast.
Summary:
If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
&V2)))), bitcast)`, but the load is used in other instructions, it leads
to looping in InstCombiner. Patch adds additional check that all users
of the load instructions are stores and then replaces all uses of load
instruction by the new one with new type.

Reviewers: RKSimon, spatel, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320496
2017-12-12 16:58:48 +00:00
Alexey Bataev c9f1d2e4a0 Revert "[InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast."
This reverts commit r320488 because of the failed asan buildbots..

llvm-svn: 320490
2017-12-12 16:05:52 +00:00
Alexey Bataev fb68c48a82 [InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast.
Summary:
If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
&V2)))), bitcast)`, but the load is used in other instructions, it leads
to looping in InstCombiner. Patch adds additional check that all users
of the load instructions are stores and then replaces all uses of load
instruction by the new one with new type.

Reviewers: RKSimon, spatel, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320488
2017-12-12 15:54:49 +00:00
Alexey Bataev ca2a8cea2f Revert "[InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast."
This reverts commit r320483 because of the failed Windows buildbots.

llvm-svn: 320485
2017-12-12 15:24:17 +00:00
Alexey Bataev 1daef8a667 [InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast.
If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
&V2)))), bitcast)`, but the load is used in other instructions, it leads
to looping in InstCombiner. Patch adds additional check that all users
of the load instructions are stores and then replaces all uses of load
instruction by the new one with new type.

Reviewers: RKSimon, spatel, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320483
2017-12-12 15:03:17 +00:00
Anna Thomas 2dd9835f35 [InstComineLoadStoreAlloca] Optimize stores to GEP off null base
Summary:
Currently, in InstCombineLoadStoreAlloca, we have simplification
rules for the following cases:
  1. load off a null
  2. load off a GEP with null base
  3. store to a null

This patch adds support for the fourth case which is store into a
GEP with null base. Since this is UB as well (and directly analogous to
the load off a GEP with null base), we can substitute the stored val
with undef in instcombine, so that SimplifyCFG can optimize this code
into unreachable code.

Note: Right now, simplifyCFG hasn't been taught about optimizing
this to unreachable and adding an llvm.trap (this is already done for
the above 3 cases).

Reviewers: majnemer, hfinkel, sanjoy, davide

Reviewed by: sanjoy, davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41026

llvm-svn: 320480
2017-12-12 14:12:33 +00:00
Igor Laevsky d63560b817 Revert r320049, r320014 and r319894
They were causing failures of the piglit OpenGL tests with AMD GPUs using the
Mesa radeonsi driver.

llvm-svn: 320466
2017-12-12 10:03:39 +00:00
Hans Wennborg 27d1c00c01 Revert r320407 "[InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast."
The tests fail (opt asserts) on Windows.

> Summary:
> If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
> &V2)))), bitcast)`, but the load is used in other instructions, it leads
> to looping in InstCombiner. Patch adds additional check that all users
> of the load instructions are stores and then replaces all uses of load
> instruction by the new one with new type.
>
> Reviewers: RKSimon, spatel, majnemer
>
> Subscribers: llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320421
2017-12-11 21:15:27 +00:00
Alexey Bataev ec128ace8a [InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast.
Summary:
If we have pattern `store (load(bitcast(select (cmp(V1, V2), &V1,
&V2)))), bitcast)`, but the load is used in other instructions, it leads
to looping in InstCombiner. Patch adds additional check that all users
of the load instructions are stores and then replaces all uses of load
instruction by the new one with new type.

Reviewers: RKSimon, spatel, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41072

llvm-svn: 320407
2017-12-11 19:11:16 +00:00
Simon Pilgrim a42a54258e [InstCombine] Fix SimplifyDemandedUseBits SHL handling (PR35515)
Don't assume that the pattern matched SRL can be cast to an Instruction (might be ConstExpr etc.)

llvm-svn: 320270
2017-12-09 23:42:56 +00:00
Evgeniy Stepanov c667c1f47a Hardware-assisted AddressSanitizer (llvm part).
Summary:
This is LLVM instrumentation for the new HWASan tool. It is basically
a stripped down copy of ASan at this point, w/o stack or global
support. Instrumenation adds a global constructor + runtime callbacks
for every load and store.

HWASan comes with its own IR attribute.

A brief design document can be found in
clang/docs/HardwareAssistedAddressSanitizerDesign.rst (submitted earlier).

Reviewers: kcc, pcc, alekseyshl

Subscribers: srhines, mehdi_amini, mgorny, javed.absar, eraman, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D40932

llvm-svn: 320217
2017-12-09 00:21:41 +00:00
Alexey Bataev ec95c6cc0a [InstCombine] PR35354: Convert store(bitcast, load bitcast (select (Cond, &V1, &V2)) --> store (, load (select(Cond, load &V1, load &V2)))
Summary:
If we have the code like this:
```
float a, b;
a = std::max(a ,b);
```
it is converted into something like this:
```
%call = call dereferenceable(4) float* @_ZSt3maxIfERKT_S2_S2_(float* nonnull dereferenceable(4) %a.addr, float* nonnull dereferenceable(4) %b.addr)
%1 = bitcast float* %call to i32*
%2 = load i32, i32* %1, align 4
%3 = bitcast float* %a.addr to i32*
store i32 %2, i32* %3, align 4
```
After inlinning this code is converted to the next:
```
%1 = load float, float* %a.addr
%2 = load float, float* %b.addr
%cmp.i = fcmp fast olt float %1, %2
%__b.__a.i = select i1 %cmp.i, float* %a.addr, float* %b.addr
%3 = bitcast float* %__b.__a.i to i32*
%4 = load i32, i32* %3, align 4
%5 = bitcast float* %arrayidx to i32*
store i32 %4, i32* %5, align 4

```
This pattern is not recognized as minmax pattern.
Patch solves this problem by converting sequence
```
store (bitcast, (load bitcast (select ((cmp V1, V2), &V1, &V2))))
```
to a sequence
```
store (,load (select((cmp V1, V2), &V1, &V2)))
```
After this the code is recognized as minmax pattern.

Reviewers: RKSimon, spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D40304

llvm-svn: 320157
2017-12-08 15:32:10 +00:00
Igor Laevsky 4a4f2e8c67 [InstCombine] Don't crash on out of bounds index in the insertelement
Differential Revision: https://reviews.llvm.org/D40390

llvm-svn: 320049
2017-12-07 15:00:52 +00:00
Sanjay Patel b6404a8ca6 [InstCombine] canonicalize constant-minus-boolean to select-of-constants
This restores the half of:
https://reviews.llvm.org/rL75531
that was reverted at:
https://reviews.llvm.org/rL159230

For the x86 case mentioned there, we now produce:
leal 1(%rdi), %eax
subl %esi, %eax

We have target hooks to invert this in DAGCombiner (and x86 is enabled) with:
https://reviews.llvm.org/rL296977
https://reviews.llvm.org/rL311731

AArch64 and possibly other targets would probably benefit from enabling those hooks too. 
See PR30327:
https://bugs.llvm.org/show_bug.cgi?id=30327#c2

Differential Revision: https://reviews.llvm.org/D40612

llvm-svn: 319964
2017-12-06 21:22:57 +00:00
Sanjay Patel 863d494730 [InstCombine] use 'auto' with 'dyn_cast'; NFC
llvm-svn: 319067
2017-11-27 18:19:32 +00:00
Sanjay Patel b3fa94586f [InstCombine] include 'sub' in the list of narrow-able binops
// trunc (binop X, C) --> binop (trunc X, C')
      // trunc (binop (ext X), Y) --> binop X, (trunc Y)

I'm grouping sub with the other binops  because that makes the code simpler
and the transforms are valid:
https://rise4fun.com/Alive/UeF
...so even though we don't expect a sub with constant Op1 or any of the
other opcodes with constant Op0 due to canonicalization rules, we might as
well handle those situations if non-canonical code somehow reaches this
point (it should just make instcombine more efficient in reaching its
end goal).

This should solve the problem that later manifests in the vectorizers in 
PR35295:
https://bugs.llvm.org/show_bug.cgi?id=35295

llvm-svn: 318404
2017-11-16 14:40:51 +00:00
Sanjay Patel 03d0cd6a81 [InstCombine] trunc (binop X, C) --> binop (trunc X, C')
Note that one-use and shouldChangeType() are checked ahead of the switch.

Without the narrowing folds, we can produce inferior vector code as shown in PR35299:
https://bugs.llvm.org/show_bug.cgi?id=35299

llvm-svn: 318323
2017-11-15 19:12:01 +00:00
Reid Kleckner 72b819b8ee [InstCombine] Salvage debug info during initial DCE
InstCombine salvages debug info for every instruction it erases from its
worklist, but it wasn't doing it during its initial DCE when populating
its worklist. This fixes that.

This should help improve availability of 'this' in optimized debug info
when casts are necessary.

llvm-svn: 318320
2017-11-15 18:51:12 +00:00
Craig Topper f7b86728fa [InstCombine] Simplify binops that are only used by a select and are fed by a select with the same condition.
Summary:
This patch optimizes a binop sandwiched between 2 selects with the same condition. Since we know its only used by the select we can propagate the appropriate input value from the earlier select.

As I'm writing this I realize I may need to avoid doing this for division in case the select was protecting a divide by zero?

Reviewers: spatel, majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39999

llvm-svn: 318267
2017-11-15 05:23:02 +00:00
Craig Topper d3e5781e53 [InstCombine] Teach visitICmpInst to not break integer absolute value idioms
Summary:
This patch adds an early out to visitICmpInst if we are looking at a compare as part of an integer absolute value idiom. Similar is already done for min/max.

In the particular case I observed in a benchmark we had an absolute value of a load from an indexed global. We simplified the compare using foldCmpLoadFromIndexedGlobal into a magic bit vector, a shift, and an and. But the load result was still used for the select and the negate part of the absolute valute idiom. So we overcomplicated the code and lost the ability to recognize it as an absolute value.

I've chosen a simpler case for the test here.

Reviewers: spatel, davide, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39766

llvm-svn: 317994
2017-11-12 02:28:21 +00:00
Craig Topper 7dd4d32431 Recommit r317510 "[InstCombine] Pull shifts through a select plus binop with constant"
The hexagon test should be fixed now.

Original commit message:

This pulls shifts through a select+binop with a constant where the select conditionally executes the binop. We already do this for just the binop, but not with the select.

This can allow us to get the select closer to other selects to enable removing one.

Differential Revision: https://reviews.llvm.org/D39222

llvm-svn: 317600
2017-11-07 18:47:24 +00:00
Craig Topper 386fc2516c [InstCombine] Update stale comment. NFC
Datalayout is no longer optional so the comment didn't match what the code currently does.

llvm-svn: 317594
2017-11-07 17:37:32 +00:00
Hans Wennborg 8c4b10e84a Revert r317510 "[InstCombine] Pull shifts through a select plus binop with constant"
This broke the CodeGen/Hexagon/loop-idiom/pmpy-mod.ll test on a bunch of buildbots.

> This pulls shifts through a select+binop with a constant where the select conditionally executes the binop. We already do this for just the binop, but not with the select.
>
> This can allow us to get the select closer to other selects to enable removing one.
>
> Differential Revision: https://reviews.llvm.org/D39222
>
> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317510 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-svn: 317518
2017-11-06 22:28:02 +00:00
Craig Topper 8917647333 [InstCombine] Pull shifts through a select plus binop with constant
This pulls shifts through a select+binop with a constant where the select conditionally executes the binop. We already do this for just the binop, but not with the select.

This can allow us to get the select closer to other selects to enable removing one.

Differential Revision: https://reviews.llvm.org/D39222

llvm-svn: 317510
2017-11-06 21:07:22 +00:00
Sanjay Patel 629c411538 [IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html
and again more recently:
http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html

...this is a step in cleaning up our fast-math-flags implementation in IR to better match
the capabilities of both clang's user-visible flags and the backend's flags for SDNode.

As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 
'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic 
reassociation - 'AllowReassoc'.

We're also adding a bit to allow approximations for library functions called 'ApproxFunc' 
(this was initially proposed as 'libm' or similar).

...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did 
look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), 
but that's apparently already used for other purposes. Also, I don't think we can just 
add a field to FPMathOperator because Operator is not intended to be instantiated. 
We'll defer movement of FMF to another day.

We keep the 'fast' keyword. I thought about removing that, but seeing IR like this:
%f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2
...made me think we want to keep the shortcut synonym.

Finally, this change is binary incompatible with existing IR as seen in the 
compatibility tests. This statement:
"Newer releases can ignore features from older releases, but they cannot miscompile 
them. For example, if nsw is ever replaced with something else, dropping it would be 
a valid way to upgrade the IR." 
( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility )
...provides the flexibility we want to make this change without requiring a new IR 
version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will 
fail to optimize some previously 'fast' code because it's no longer recognized as 
'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'.

Note: an inter-dependent clang commit to use the new API name should closely follow 
commit.

Differential Revision: https://reviews.llvm.org/D39304

llvm-svn: 317488
2017-11-06 16:27:15 +00:00
Matthew Simpson b6915fbfa2 [InstCombine] Simplify selects that test cmpxchg instructions
If a select instruction tests the returned flag of a cmpxchg instruction and
selects between the returned value of the cmpxchg instruction and its compare
operand, the result of the select will always be equal to its false value.

Differential Revision: https://reviews.llvm.org/D39383

llvm-svn: 316994
2017-10-31 12:34:02 +00:00
Daniel Neilson f9c7d29c77 Create instruction classes for identifying any atomicity of memory intrinsic. (NFC)
Summary:
For reference, see: http://lists.llvm.org/pipermail/llvm-dev/2017-August/116589.html

This patch fleshes out the instruction class hierarchy with respect to atomic and
non-atomic memory intrinsics. With this change, the relevant part of the class
hierarchy becomes:

IntrinsicInst
  -> MemIntrinsicBase (methods-only class)
    -> MemIntrinsic (non-atomic intrinsics)
      -> MemSetInst
      -> MemTransferInst
        -> MemCpyInst
        -> MemMoveInst
    -> AtomicMemIntrinsic (atomic intrinsics)
      -> AtomicMemSetInst
      -> AtomicMemTransferInst
        -> AtomicMemCpyInst
        -> AtomicMemMoveInst
    -> AnyMemIntrinsic (both atomicities)
      -> AnyMemSetInst
      -> AnyMemTransferInst
        -> AnyMemCpyInst
        -> AnyMemMoveInst

This involves some class renaming:
    ElementUnorderedAtomicMemCpyInst -> AtomicMemCpyInst
    ElementUnorderedAtomicMemMoveInst -> AtomicMemMoveInst
    ElementUnorderedAtomicMemSetInst -> AtomicMemSetInst
A script for doing this renaming in downstream trees is included below.

An example of where the Any* classes should be used in LLVM is when reasoning
about the effects of an instruction (ex: aliasing).

---
Script for renaming AtomicMem* classes:
PREFIXES="[<,([:space:]]"
CLASSES="MemIntrinsic|MemTransferInst|MemSetInst|MemMoveInst|MemCpyInst"
SUFFIXES="[;)>,[:space:]]"

REGEX="(${PREFIXES})ElementUnorderedAtomic(${CLASSES})(${SUFFIXES})"
REGEX2="visitElementUnorderedAtomic(${CLASSES})"

FILES=$( grep -E "(${REGEX}|${REGEX2})" -r . | tr ':' ' ' | awk '{print $1}' | sort | uniq )

SED_SCRIPT="s~${REGEX}~\1Atomic\2\3~g"
SED_SCRIPT2="s~${REGEX2}~visitAtomic\1~g"

for f in $FILES; do
    echo "Processing: $f"
    sed  -i ".bak" -E "${SED_SCRIPT};${SED_SCRIPT2};${EA_SED_SCRIPT};${EA_SED_SCRIPT2}" $f
done

Reviewers: sanjoy, deadalnix, apilipenko, anna, skatkov, mkazantsev

Reviewed By: sanjoy

Subscribers: hfinkel, jholewinski, arsenm, sdardis, nhaehnle, JDevlieghere, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D38419

llvm-svn: 316950
2017-10-30 19:51:48 +00:00
Eugene Zelenko 7f0f9bc5ab [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316503
2017-10-24 21:24:53 +00:00
Marek Olsak ce76ea0394 AMDGPU: Add new intrinsic llvm.amdgcn.kill(i1)
Summary:
Kill the thread if operand 0 == false.
llvm.amdgcn.wqm.vote can be applied to the operand.

Also allow kill in all shader stages.

Reviewers: arsenm, nhaehnle

Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D38544

llvm-svn: 316427
2017-10-24 10:27:13 +00:00
Marek Olsak 2114fc3bcb AMDGPU: Add llvm.amdgcn.wqm.vote intrinsic
Reviewers: arsenm, nhaehnle

Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye

Differential Revision: https://reviews.llvm.org/D38543

llvm-svn: 316426
2017-10-24 10:26:59 +00:00
Sanjay Patel 42135beac8 [InstCombine] don't unnecessarily generate a constant; NFCI
llvm-svn: 315910
2017-10-16 14:47:24 +00:00
Nikolai Bozhenov 0e7ebbccc7 Move folding of icmp with zero after checking for min/max idioms.
Summary:
The following transformation for cmp instruction:

  icmp smin(x, PositiveValue), 0 -> icmp x, 0

should only be done after checking for min/max to prevent infinite
looping caused by a reverse canonicalization. That is why this
transformation was moved to place after the mentioned check.

Reviewers: spatel, efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38934

Patch by: Artur Gainullin <artur.gainullin@intel.com>

llvm-svn: 315895
2017-10-16 09:19:21 +00:00
Sanjay Patel 934738a3da revert r314984: revert r314698 - [InstCombine] remove one-use restriction for icmp (shr exact X, C1), C2 --> icmp X, (C2<<C1)
Recommitting r314698. The bug exposed by this change should be fixed with:
https://reviews.llvm.org/rL315579 

llvm-svn: 315857
2017-10-15 15:39:15 +00:00
Sanjay Patel b869f76d85 [InstCombine] use m_Neg() to reduce code; NFCI
llvm-svn: 315762
2017-10-13 21:28:50 +00:00
Sanjay Patel f0242de143 [InstCombine] move code to remove repeated constant check; NFCI
Also, consolidate tests for this fold in one place.

llvm-svn: 315745
2017-10-13 20:29:11 +00:00
Sanjay Patel 28b3aa3663 [InstCombine] recycle adds for better efficiency
Also, clean up unnecessary matcher capture variable initializations.

llvm-svn: 315743
2017-10-13 20:12:21 +00:00
Sanjay Patel 2118952162 [InstCombine] use local var to reduce code duplication; NFCI
llvm-svn: 315728
2017-10-13 18:32:53 +00:00
Sanjay Patel c419c9f640 [InstCombine] add hasOneUse check to add-zext-add fold to prevent increasing instructions
llvm-svn: 315718
2017-10-13 17:47:25 +00:00
Sanjay Patel 76ed9eab29 [InstCombine] use AddOne helper to reduce code; NFC
llvm-svn: 315709
2017-10-13 17:00:47 +00:00
Sanjay Patel 8d810fee43 [InstCombine] rearrange code to remove repeated constant check; NFCI
llvm-svn: 315703
2017-10-13 16:43:58 +00:00
Sanjay Patel 2150651ac3 [InstCombine] allow zext(bool) + C --> select bool, C+1, C for vector types
The backend should be prepared for this transform after:
https://reviews.llvm.org/rL311731

llvm-svn: 315701
2017-10-13 16:29:38 +00:00
Xinliang David Li 4cdc9dab0a Renable r314928
Eliminate inttype phi with inttoptr/ptrtoint.

 This version fixed a bug in finding the matching
 phi -- the order of the incoming blocks may be 
 different (triggered in self build on Windows).
 A new test case is added.

llvm-svn: 315272
2017-10-10 05:07:54 +00:00
Adam Nemet 0965da2055 Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*
Sync it up with the name of the class actually defined here.  This has been
bothering me for a while...

llvm-svn: 315249
2017-10-09 23:19:02 +00:00
Sanjay Patel ce36b03b03 [InstCombine] fix formatting; NFC
llvm-svn: 315223
2017-10-09 17:54:46 +00:00
Sanjay Patel 72d339abb7 [InstCombine] use correct type when propagating constant condition in simplifyDivRemOfSelectWithZeroOp (PR34856)
llvm-svn: 315130
2017-10-06 23:43:06 +00:00
Sanjay Patel ae2e3a44d2 [InstCombine] rename SimplifyDivRemOfSelect to be clearer, add comments, simplify code; NFCI
There's at least one bug here - this code can fail with vector types (PR34856).
It's also being called for FREM; I'm still trying to understand how that is valid.

llvm-svn: 315127
2017-10-06 23:20:16 +00:00
Reid Kleckner b6b210e61f Revert "Roll forward r314928"
This appears to be miscompiling Clang, as shown on two Windows bootstrap
bots:
http://lab.llvm.org:8011/builders/clang-x86-windows-msvc2015/builds/7611
http://lab.llvm.org:8011/builders/clang-x64-ninja-win7/builds/6870

Nothing else is in the blame list. Both emit errors on this valid code
in the Windows ucrt headers:

C:\...\ucrt\malloc.h:95:32: error: invalid operands to binary expression ('char *' and 'int')
            _Ptr = (char*)_Ptr + _ALLOCA_S_MARKER_SIZE;
                   ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~

I am attempting to reproduce this now.

This reverts r315044

llvm-svn: 315108
2017-10-06 21:17:51 +00:00
Xinliang David Li bcd36f7c5a Roll forward r314928
Fixed ThinLTO bootstrap failure : track new
bitcast per incomingVal. Added new tests.

llvm-svn: 315044
2017-10-06 05:15:25 +00:00
Sanjay Patel 7ac2db6a48 [InstCombine] improve folds for icmp gt/lt (shr X, C1), C2
We can always eliminate the shift in: icmp gt/lt (shr X, C1), C2 --> icmp gt/lt X, C'
This patch was supposed to just be an efficiency improvement because we were doing this 3-step process to fold:

IC: Visiting:   %c = icmp ugt i4 %s, 1
IC: ADD:   %s = lshr i4 %x, 1
IC: ADD:   %1 = udiv i4 %x, 2
IC: Old =   %c = icmp ugt i4 %1, 1
    New =   <badref> = icmp uge i4 %x, 4
IC: ADD:   %c = icmp uge i4 %x, 4
IC: ERASE   %2 = icmp ugt i4 %1, 1
IC: Visiting:   %c = icmp uge i4 %x, 4
IC: Old =   %c = icmp uge i4 %x, 4
    New =   <badref> = icmp ugt i4 %x, 3
IC: ADD:   %c = icmp ugt i4 %x, 3
IC: ERASE   %2 = icmp uge i4 %x, 4
IC: Visiting:   %c = icmp ugt i4 %x, 3
IC: DCE:   %1 = udiv i4 %x, 2
IC: ERASE   %1 = udiv i4 %x, 2
IC: DCE:   %s = lshr i4 %x, 1
IC: ERASE   %s = lshr i4 %x, 1
IC: Visiting:   ret i1 %c

When we could go directly to canonical icmp form:

IC: Visiting:   %c = icmp ugt i4 %s, 1
IC: Old =   %c = icmp ugt i4 %s, 1
    New =   <badref> = icmp ugt i4 %x, 3
IC: ADD:   %c = icmp ugt i4 %x, 3
IC: ERASE   %1 = icmp ugt i4 %s, 1
IC: ADD:   %s = lshr i4 %x, 1
IC: DCE:   %s = lshr i4 %x, 1
IC: ERASE   %s = lshr i4 %x, 1
IC: Visiting:   %c = icmp ugt i4 %x, 3

...but then I noticed that the folds were incomplete too:
https://godbolt.org/g/aB2hLE

Here are attempts to prove the logic with Alive:
https://rise4fun.com/Alive/92o

Name: lshr_ult
Pre: ((C2 << C1) u>> C1) == C2
%sh = lshr i8 %x, C1
%r = icmp ult i8 %sh, C2
  =>
%r = icmp ult i8 %x, (C2 << C1)

Name: ashr_slt
Pre: ((C2 << C1) >> C1) == C2
%sh = ashr i8 %x, C1
%r = icmp slt i8 %sh, C2
  =>
%r = icmp slt i8 %x, (C2 << C1)

Name: lshr_ugt
Pre: (((C2+1) << C1) u>> C1) == (C2+1)
%sh = lshr i8 %x, C1
%r = icmp ugt i8 %sh, C2
  =>
%r = icmp ugt i8 %x, ((C2+1) << C1) - 1

Name: ashr_sgt
Pre: (C2 != 127) && ((C2+1) << C1 != -128) && (((C2+1) << C1) >> C1) == (C2+1)
%sh = ashr i8 %x, C1
%r = icmp sgt i8 %sh, C2
  =>
%r = icmp sgt i8 %x, ((C2+1) << C1) - 1

Name: ashr_exact_sgt
Pre: ((C2 << C1) >> C1) == C2
%sh = ashr exact i8 %x, C1
%r = icmp sgt i8 %sh, C2
  =>
%r = icmp sgt i8 %x, (C2 << C1)

Name: ashr_exact_slt
Pre: ((C2 << C1) >> C1) == C2
%sh = ashr exact i8 %x, C1
%r = icmp slt i8 %sh, C2
  =>
%r = icmp slt i8 %x, (C2 << C1)

Name: lshr_exact_ugt
Pre: ((C2 << C1) u>> C1) == C2
%sh = lshr exact i8 %x, C1
%r = icmp ugt i8 %sh, C2
  =>
%r = icmp ugt i8 %x, (C2 << C1)

Name: lshr_exact_ult
Pre: ((C2 << C1) u>> C1) == C2
%sh = lshr exact i8 %x, C1
%r = icmp ult i8 %sh, C2
  =>
%r = icmp ult i8 %x, (C2 << C1)

We did something similar for 'shl' in D28406.

Differential Revision: https://reviews.llvm.org/D38514

llvm-svn: 315021
2017-10-05 21:11:49 +00:00
Sanjay Patel f11b5b4f87 revert r314698 - [InstCombine] remove one-use restriction for icmp (shr exact X, C1), C2 --> icmp X, (C2<<C1)
There is a bot failure that appears to be related to this change:
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15-selfhost-neon/builds/2117

...so reverting to confirm that and attempting to keep the bot green while investigating.

llvm-svn: 314984
2017-10-05 14:26:15 +00:00
Craig Topper 17b0c78447 [InstCombine] Fix a vector splat handling bug in transformZExtICmp.
We were using an i1 type and then zero extending to a vector. Instead just create the 0/1 directly as a ConstantInt with the correct type. No need to ask ConstantExpr to zero extend for us.

This bug is a bit tricky to hit because it requires us to visit a zext of an icmp that would normally be simplified to true/false, but that icmp hasnt' been visited yet. In the test case this zext and icmp were created by visiting a udiv and due to worklist ordering we got to the zext first.

Fixes PR34841.

llvm-svn: 314971
2017-10-05 07:59:11 +00:00
Xinliang David Li 04ab11a08a Revert r314928 to investigate thinLTO bootstrap failure
llvm-svn: 314961
2017-10-05 01:40:13 +00:00
Craig Topper 7a93092399 [InstCombine] Improve support for ashr in foldICmpAndShift
We can support ashr similar to lshr, if we know that none of the shifted in bits are used. In that case SimplifyDemandedBits would normally convert it to lshr. But that conversion doesn't happen if the shift has additional users.

Differential Revision: https://reviews.llvm.org/D38521

llvm-svn: 314945
2017-10-04 23:06:13 +00:00
Xinliang David Li 7a73757358 Recommit r314561 after fixing msan build failure
(trial 2) Incoming val defined by terminator instruction which
also requires bitcasts can not be handled.

llvm-svn: 314928
2017-10-04 20:17:55 +00:00
Craig Topper df63b96811 [InstCombine] Use isSignBitCheck to simplify an if statement. Directly create new sign bit compares instead of manipulating the constant. NFCI
Since we no longer had the direct constant compares, manipulating the constant seemeded less clear.

llvm-svn: 314830
2017-10-03 19:14:23 +00:00
Craig Topper 8ed1aa91bd [InstCombine] Change a bunch of methods to take APInts by reference instead of pointer.
This allows us to remove a bunch of dereferences and only have a few dereferences at the call sites.

llvm-svn: 314762
2017-10-03 05:31:07 +00:00
Craig Topper 664c4d0190 [InstCombine] Replace an equality compare of two APInt pointers with a compare of the APInts themselves.
Apparently this works by virtue of the fact that the pointers are pointers to the APInts stored inside of the ConstantInt objects. But I really don't think we should be relying on that.

llvm-svn: 314761
2017-10-03 04:55:04 +00:00
Sanjay Patel 6e17c00a88 [InstCombine] remove one-use restriction for icmp (shr exact X, C1), C2 --> icmp X, (C2<<C1)
llvm-svn: 314698
2017-10-02 18:26:44 +00:00
Dehao Chen f464627f28 Update getMergedLocation to check the instruction type and merge properly.
Summary: If the merged instruction is call instruction, we need to set the scope to the closes common scope between 2 locations, otherwise it will cause trouble when the call is getting inlined.

Reviewers: dblaikie, aprantl

Reviewed By: dblaikie, aprantl

Subscribers: llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D37877

llvm-svn: 314694
2017-10-02 18:13:14 +00:00
Craig Topper 6e025a3ecc [InstCombine] Use APInt for all the math in foldICmpDivConstant
Summary: This currently uses ConstantExpr to do its math, but as noted in a TODO it can all be done directly on APInt.

Reviewers: spatel, majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38440

llvm-svn: 314640
2017-10-01 23:53:54 +00:00
Daniel Jasper 3c9c60c727 Revert r314579: "Recommi r314561 after fixing over-debug assertion".
And follow-up r314585.
Leads to segfaults. I'll forward reproduction instructions to the patch
author.

Also, for a recommit, still add the original patch description.
Otherwise, it becomes really tedious to find out what a patch actually
does. The fact that it is a recommit with a fix is somewhat secondary.

llvm-svn: 314622
2017-10-01 09:53:53 +00:00
Xinliang David Li b8aac3ac19 Fix buildbot failure -- tighten type check for matching phi
llvm-svn: 314585
2017-09-30 05:27:46 +00:00
Xinliang David Li 3409d9c07f Recommi r314561 after fixing over-debug assertion
llvm-svn: 314579
2017-09-30 00:46:32 +00:00
Xinliang David Li 455dec098b Revert 314561 due to debug build assertion failure
llvm-svn: 314563
2017-09-29 22:30:34 +00:00
Xinliang David Li 5b9d96825b Eliminate PHI (int typed) which has only one use by intptr
This patch will eliminate redundant intptr/ptrtoint that pessimizes
analyses such as SCEV, AA and will make optimization passes such
as auto-vectorization more powerful.

Differential revision: http://reviews.llvm.org/D37832

llvm-svn: 314561
2017-09-29 22:10:15 +00:00
Craig Topper 0cd25942f7 Revert r314017 '[InstCombine] Simplify check for RHS being a splat constant in foldICmpUsingKnownBits by just checking Op1Min==Op1Max rather than going through m_APInt.'
This reverts r314017 and similar code added in later commits. It seems to not work for pointer compares and is causing a bot failure for the last several days.

llvm-svn: 314360
2017-09-27 22:57:18 +00:00
Chad Rosier d8b4b06f5d [InstCombine] Gating select arithmetic optimization.
These changes faciliate positive behavior for arithmetic based select
expressions that match its translation criteria, keeping code size gated to
neutral or improved scenarios.

Patch by Michael Berg <michael_c_berg@apple.com>!

Differential Revision: https://reviews.llvm.org/D38263

llvm-svn: 314320
2017-09-27 17:16:51 +00:00
Craig Topper 8bf622174d [InstCombine] Remove one use restriction on the shift for calls to foldICmpAndShift.
If this transformation succeeds, we're going to remove our dependency on the shift by rewriting the and. So it doesn't matter how many uses the shift has.

This distributes the one use check to other transforms in foldICmpAndConstConst that do need it.

Differential Revision: https://reviews.llvm.org/D38206

llvm-svn: 314233
2017-09-26 18:47:25 +00:00
Craig Topper 30dc9797e9 [InstCombine] Move an optimization from foldICmpAndConstConst to foldICmpUsingKnownBits
All this optimization cares about is knowing how many low bits of LHS is known to be zero and whether that means that the result is 0 or greater than the RHS constant. It doesn't matter where the zeros in the low bits came from. So we don't need to specifically look for an AND. Instead we can use known bits.

Differential Revision: https://reviews.llvm.org/D38195

llvm-svn: 314153
2017-09-25 21:15:00 +00:00
Sanjay Patel ecb175608f [InstCombine] remove extract-of-select vector transform (2nd try)
The 1st attempt at this:
https://reviews.llvm.org/rL314117
was reverted at:
https://reviews.llvm.org/rL314118

because of bot fails for clang tests that were checking optimized IR. That should be fixed with:
https://reviews.llvm.org/rL314144
...so try again. 

Original commit message:

The transform to convert an extract-of-a-select-of-vectors was added at:
https://reviews.llvm.org/rL194013

And a question about the validity of this transform was raised in the review:
https://reviews.llvm.org/D1539:
...but not answered AFAICT>

Most of the motivating cases in that patch are now handled by other combines. These are the tests that were added with
the original commit, but they are not regressing even after we remove the transform in this patch.

The diffs we see after removing this transform cause us to avoid increasing the instruction count, so we don't want to do
those transforms as canonicalizations.

The motivation for not turning a vector-select-of-vectors into a scalar operation is shown in PR33301:
https://bugs.llvm.org/show_bug.cgi?id=33301
...in those cases, we'll get vector ops with this patch rather than the vector/scalar mix that we currently see.

Differential Revision: https://reviews.llvm.org/D38006

llvm-svn: 314147
2017-09-25 20:30:53 +00:00
Sanjay Patel aa7f750bec revert r314117 because there are bogus clang tests that depend on the optimizer
llvm-svn: 314118
2017-09-25 17:00:04 +00:00
Sanjay Patel 9639897d77 [InstCombine] remove extract-of-select vector transform
The transform to convert an extract-of-a-select-of-vectors was added at:
rL194013

And a question about the validity of this transform was raised in the review:
https://reviews.llvm.org/D1539:
...but not answered AFAICT>

Most of the motivating cases in that patch are now handled by other combines. These are the tests that were added with
the original commit, but they are not regressing even after we remove the transform in this patch.

The diffs we see after removing this transform cause us to avoid increasing the instruction count, so we don't want to do
those transforms as canonicalizations.

The motivation for not turning a vector-select-of-vectors into a scalar operation is shown in PR33301:
https://bugs.llvm.org/show_bug.cgi?id=33301
...in those cases, we'll get vector ops with this patch rather than the vector/scalar mix that we currently see.

Differential Revision: https://reviews.llvm.org/D38006

llvm-svn: 314117
2017-09-25 16:41:34 +00:00
Craig Topper ea927baee2 [InstCombine] Teach foldICmpUsingKnownBits to simplify SLE/SGE/ULE/UGE to equality comparisons when the min/max ranges intersect in a single value.
This is the inverse of what we do for SGT/SLT/UGT/ULT.

llvm-svn: 314032
2017-09-22 21:47:22 +00:00
Craig Topper 3f364aa908 [InstCombine] Add constant splat handling to one of the ICMP_SLT/SGT cases in foldICmpUsingKnownBits.
llvm-svn: 314025
2017-09-22 19:54:15 +00:00
Craig Topper 3edda87c42 [InstCombine] Move the call to isSignBitCheck into getDemandedBitsLHSMask instead of calling it outside and passing its result through a flag. NFCI
The result of the isSignBitCheck isn't used anywhere else and this allows us to share the m_APInt call in the likely case that it isn't a sign bit check.

llvm-svn: 314018
2017-09-22 18:57:23 +00:00
Craig Topper 5b35b68785 [InstCombine] Simplify check for RHS being a splat constant in foldICmpUsingKnownBits by just checking Op1Min==Op1Max rather than going through m_APInt.
llvm-svn: 314017
2017-09-22 18:57:22 +00:00
Craig Topper 2c9b7d7894 [InstCombine] Make cases for ICMP_UGT/ICMP_ULT use similar formatting since they use similar code. NFC
llvm-svn: 314016
2017-09-22 18:57:20 +00:00
Reid Kleckner 0fe506bc5e Re-land r313825: "[IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare"
The fix is to avoid invalidating our insertion point in
replaceDbgDeclare:
     Builder.insertDeclare(NewAddress, DIVar, DIExpr, Loc, InsertBefore);
+    if (DII == InsertBefore)
+      InsertBefore = &*std::next(InsertBefore->getIterator());
     DII->eraseFromParent();

I had to write a unit tests for this instead of a lit test because the
use list order matters in order to trigger the bug.

The reduced C test case for this was:
  void useit(int*);
  static inline void inlineme() {
    int x[2];
    useit(x);
  }
  void f() {
    inlineme();
    inlineme();
  }

llvm-svn: 313905
2017-09-21 19:52:03 +00:00
Daniel Jasper 7d2f38d600 Revert r313825: "[IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare"
.. as well as the two subsequent changes r313826 and r313875.

This leads to segfaults in combination with ASAN. Will forward repro
instructions to the original author (rnk).

llvm-svn: 313876
2017-09-21 12:07:33 +00:00
Craig Topper 18887bf179 [InstCombine] Teach getDemandedBitsLHSMask to handle constant splat vectors
This replaces a ConstantInt dyn_cast with m_APInt

Differential Revision: https://reviews.llvm.org/D38100

llvm-svn: 313840
2017-09-20 23:48:58 +00:00
Reid Kleckner 3f547e87b2 [IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare
Summary:
This implements the design discussed on llvm-dev for better tracking of
variables that live in memory through optimizations:
  http://lists.llvm.org/pipermail/llvm-dev/2017-September/117222.html

This is tracked as PR34136

llvm.dbg.addr is intended to be produced and used in almost precisely
the same way as llvm.dbg.declare is today, with the exception that it is
control-dependent. That means that dbg.addr should always have a
position in the instruction stream, and it will allow passes that
optimize memory operations on local variables to insert llvm.dbg.value
calls to reflect deleted stores. See SourceLevelDebugging.rst for more
details.

The main drawback to generating DBG_VALUE machine instrs is that they
usually cause LLVM to emit a location list for DW_AT_location. The next
step will be to teach DwarfDebug.cpp how to recognize more DBG_VALUE
ranges as not needing a location list, and possibly start setting
DW_AT_start_offset for variables whose lifetimes begin mid-scope.

Reviewers: aprantl, dblaikie, probinson

Subscribers: eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D37768

llvm-svn: 313825
2017-09-20 21:52:33 +00:00
Craig Topper 562bf99ee6 [InstCombine] Handle (X & C2) < C1 --> (X & C2) == 0
We already did (X & C2) > C1 --> (X & C2) != 0, if any bit set in (X & C2) will produce a result greater than C1. But there is an equivalent inverse condition with <= C1 (which will be canonicalized to < C1+1)

Differential Revision: https://reviews.llvm.org/D38065

llvm-svn: 313819
2017-09-20 21:18:17 +00:00
Craig Topper a0c897f634 [InstCombine] Use APInt::getActiveBits() to avoid creating an APInt from a trailing zero count to do a comparison. NFCI
llvm-svn: 313792
2017-09-20 18:49:29 +00:00
Quentin Colombet aa103b3d86 [InstCombine] Add select simplifications
In these cases, two selects have constant selectable operands for
both the true and false components and have the same conditional
expression.
We then create two arithmetic operations of the same type and feed a
final select operation using the result of the true arithmetic for the true
operand and the result of the false arithmetic for the false operand and reuse
the original conditionl expression.
The arithmetic operations are naturally folded as a consequence, leaving
only the newly formed select to replace the old arithmetic operation.

Patch by: Michael Berg <michael_c_berg@apple.com>
Differential Revision: https://reviews.llvm.org/D37019

llvm-svn: 313774
2017-09-20 17:32:16 +00:00
Craig Topper f264fcc704 [X86] Remove VPERM2F128/VPERM2I128 intrinsics and autoupgrade to native shuffles.
I've moved the test cases from the InstCombine optimizations to the backend to keep the coverage we had there. It covered every possible immediate so I've preserved the resulting shuffle mask for each of those immediates.

llvm-svn: 313450
2017-09-16 07:36:14 +00:00
Reid Kleckner 8a1cd91016 [InstCombine] Add a flag to disable LowerDbgDeclare
Summary:
This should improve optimized debug info for address-taken variables at
the cost of inaccurate debug info in some situations.

We patched this into clang and deployed this change to Chromium
developers, and this significantly improved debuggability of optimized
code. The long-term solution to PR34136 seems more and more like it's
going to take a while, so I would like to commit this change under a
flag so that it can be used as a stop-gap measure.

This flag should really help so for C++ aggregates like std::string and
std::vector, which are typically address-taken, even after inlining, and
cannot be SROA-ed.

Reviewers: aprantl, dblaikie, probinson, dberlin

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D36596

llvm-svn: 313108
2017-09-13 01:43:25 +00:00
Uriel Korach 18972237a2 Test commit
llvm-svn: 312878
2017-09-10 08:31:22 +00:00
Nuno Lopes 404f106d71 Merge isKnownNonNull into isKnownNonZero
It now knows the tricks of both functions.
Also, fix a bug that considered allocas of non-zero address space to be always non null

Differential Revision: https://reviews.llvm.org/D37628

llvm-svn: 312869
2017-09-09 18:23:11 +00:00
Sanjay Patel 6840c5ff75 [ValueTracking, InstCombine] canonicalize fcmp ord/uno with non-NAN ops to null constants
This is a preliminary step towards solving the remaining part of PR27145 - IR for isfinite():
https://bugs.llvm.org/show_bug.cgi?id=27145

In order to solve that one more generally, we need to add matching for and/or of fcmp ord/uno
with a constant operand.

But while looking at those patterns, I realized we were missing a canonicalization for nonzero
constants. Rather than limiting to just folds for constants, we're adding a general value
tracking method for this based on an existing DAG helper.

By transforming everything to 0.0, we can simplify the existing code in foldLogicOfFCmps()
and pick up missing vector folds.

Differential Revision: https://reviews.llvm.org/D37427

llvm-svn: 312591
2017-09-05 23:13:13 +00:00
Craig Topper 28d6d962d5 [InstCombine] Move foldSelectICmpAnd helper function earlier in the file to enable reuse in a future patch.
llvm-svn: 312518
2017-09-05 05:26:37 +00:00
Craig Topper 4c766a0559 [InstCombine] In foldSelectIntoOp, avoid creating a Constant before we know for sure we're going to use it and avoid an unnecessary call to m_APInt.
Instead of creating a Constant and then calling m_APInt with it (which will always return true). Just create an APInt initially, and use that for the checks in isSelect01 function. If it turns out we do need the Constant, create it from the APInt.

This is a refactor for a future patch that will do some more checks of the constant values here.

llvm-svn: 312517
2017-09-05 05:26:36 +00:00
Sanjay Patel bc6da4e40f [InstCombine] replace unnecessary fcmp fold with assert
See https://reviews.llvm.org/rL312411 for related InstSimplify tests.

llvm-svn: 312421
2017-09-02 18:10:29 +00:00
Sanjay Patel 64fc5daf42 [InstCombine] combine foldAndOfFCmps and foldOrOfFcmps; NFCI
In addition to removing chunks of duplicated code, we don't
want these to diverge. If there's a fold for one, there
should be a fold of the other via DeMorgan's Laws.

llvm-svn: 312420
2017-09-02 17:53:33 +00:00
Sanjay Patel 275bb5a14e [InstCombine] fix misnamed locals and use them to reduce code; NFCI
We had these locals:
Value *Op0RHS = LHS->getOperand(1);
Value *Op1LHS = RHS->getOperand(0);
...so we confusingly transposed the meaning of left/right and op0/op1.

llvm-svn: 312418
2017-09-02 17:17:17 +00:00
Sanjay Patel da6f9b2fee [InstCombine] remove unnecessary code; NFC
llvm-svn: 312416
2017-09-02 16:32:37 +00:00
Sanjay Patel 4c52f765a5 [InstCombine] move related functions next to each other; NFC
This makes it easier to see that they're almost duplicates.
As with the similar icmp functions, there should be identical 
folds for both logic ops because those are DeMorganized variants.

llvm-svn: 312415
2017-09-02 16:30:27 +00:00
Sanjay Patel 6b139464ca [InstCombine] use local variable to reduce code duplication; NFCI
llvm-svn: 312414
2017-09-02 15:11:55 +00:00
Craig Topper 924f20262b [InstCombine][InstSimplify] Teach decomposeBitTestICmp to look through truncate instructions
This patch teaches decomposeBitTestICmp to look through truncate instructions on the input to the compare. If a truncate is found it will now return the pre-truncated Value and appropriately extend the APInt mask.

This allows some code to be removed from InstSimplify that was doing this functionality.

This allows InstCombine's bit test combining code to match a pre-truncate Value with the same Value appear with an 'and' on another icmp. Or it allows us to combine a truncate to i16 and a truncate to i8. This also required removing the type check from the beginning of getMaskedTypeForICmpPair, but I believe that's ok because we still have to find two values from the input to each icmp that are equal before we'll do any transformation. So the type check was really just serving as an early out.

There was one user of decomposeBitTestICmp that didn't want to look through truncates, so I've added a flag to prevent that behavior when necessary.

Differential Revision: https://reviews.llvm.org/D37158

llvm-svn: 312382
2017-09-01 21:27:34 +00:00
Craig Topper d3b465606a [InstCombine] Don't require the compare types to be the same in getMaskedTypeForICmpPair.
A future patch will make the code look through truncates feeding the compare. So the compares might be different types but the pretruncated types might be the same.

This should be safe because we still require the same Value* to be used truncated or not in both compares. So that serves to ensure the types are the same.

llvm-svn: 312381
2017-09-01 21:27:31 +00:00
Craig Topper 085c1f4dea [InstCombine] When converting decomposeBitTestICmp's APInt return to ConstantInt, make sure we use the type from the Value* that was also returned from decomposeBitTestICmp.
Previously we used the type from the LHS of the compare, but a future patch will change decomposeBitTestICmp to look through truncates so it will return a pretruncated Value* and the type needs to match that.

llvm-svn: 312380
2017-09-01 21:27:29 +00:00
Sanjay Patel e6b48a1b02 [InstCombine] improve demanded vector elements analysis of insertelement
Recurse instead of returning on the first found optimization. Also, return early in the caller
instead of continuing because that allows another round of simplification before we might
potentially lose undef information from a shuffle mask by eliminating the shuffle.

As noted in the review, we could probably do better and be more efficient by moving all of
demanded elements into a separate pass, but this is yet another quick fix to instcombine.

Differential Revision: https://reviews.llvm.org/D37236

llvm-svn: 312248
2017-08-31 15:57:17 +00:00
Sanjay Patel 6f7ac7e402 [InstCombine] remove unnecessary vector select fold; NFCI
This code is double-dead:
1. We simplify all selects with constant true/false condition in InstSimplify.
   I've minimized/moved the tests to show that works as expected.
2. All remaining vector selects with a constant condition are canonicalized to
   shufflevector, so we really can't see this pattern.

llvm-svn: 312123
2017-08-30 14:04:57 +00:00
Florian Hahn b992feee13 [InstCombine] Fold insert sequence if first ins has multiple users.
Summary:
If the first insertelement instruction has multiple users and inserts at
position 0, we can re-use this instruction when folding a chain of
insertelement instructions. As we need to generate the first
insertelement instruction anyways, this should be a strict improvement.

We could get rid of the restriction of inserting at position 0 by
creating a different shufflemask, but it is probably worth to keep the
first insertelement instruction with position 0, as this is easier to do
efficiently than at other positions I think.

Reviewers: grosser, mkuper, fpetrogalli, efriedma

Reviewed By: fpetrogalli

Subscribers: gareevroman, llvm-commits

Differential Revision: https://reviews.llvm.org/D37064

llvm-svn: 312110
2017-08-30 10:54:21 +00:00
Craig Topper 4431bfe88c [InstCombine] Support vector splats in transformZExtICmp
This patch adds splat support to transformZExtICmp. The test cases are vector versions of tests that failed when commenting out parts of the existing scalar code.

One test didn't vectorize optimize properly due to another bug so a TODO has been added.

Differential Revision: https://reviews.llvm.org/D37253

llvm-svn: 312023
2017-08-29 18:58:13 +00:00
Craig Topper 5d6ddda92d [InstCombine] Teach foldSelectICmpAndOr to handle vector splats
This was pretty close to working already. While I was here I went ahead and passed the ICmpInst pointer from the caller instead of doing a dyn_cast that can never fail.

Differential Revision: https://reviews.llvm.org/D37237

llvm-svn: 311960
2017-08-29 00:13:49 +00:00
Craig Topper 516e39cd38 [InstCombine] Teach select01 helper of foldSelectIntoOp to handle vector splats
We were handling some vectors in foldSelectIntoOp, but not if the operand of the bin op was any kind of vector constant. This patch fixes it to treat vector splats the same as scalars.

Differential Revision: https://reviews.llvm.org/D37232

llvm-svn: 311940
2017-08-28 22:00:27 +00:00
Craig Topper 3763f0e00d [InstCombine] Call hasNoSignedWrap instead of hasNoUnsignedWrap to get the NSW flag when handling Add in SimplifyDemandedUseBits.
This is a typo from r311789.

This should fix PR34349.

llvm-svn: 311902
2017-08-28 18:44:28 +00:00
Craig Topper 35171e5d67 [InstCombine] Don't fall back to only calling computeKnownBits if the upper bit of Add/Sub is demanded.
Just create an all 1s demanded mask and continue recursing like normal. The recursive calls should be able to handle an all 1s mask and do the right thing.

The only time we should care about knowing whether the upper bit was demanded is when we need to know if we should clear the NSW/NUW flags.

Now that we have a consistent path through the code for all cases, use KnownBits::computeForAddSub to compute the known bits at the end since we already have the LHS and RHS.

My larger goal here is to move the code that turns add into xor if only 1 bit is demanded and no bits below it are non-zero from InstCombiner::OptAndOp to here. This will allow it to be more general instead of just looking for 'add' and 'and' with constant RHS.

Differential Revision: https://reviews.llvm.org/D36486

llvm-svn: 311789
2017-08-25 18:39:40 +00:00
Amjad Aboud 22178dd33b [InstCombine] Consider more cases where SimplifyDemandedUseBits does not convert AShr to LShr.
There are cases where AShr have better chance to be optimized than LShr, especially when the demanded bits are not known to be Zero, and also known to be similar to the sign bit.

Differential Revision: https://reviews.llvm.org/D36936

llvm-svn: 311773
2017-08-25 11:07:54 +00:00
Sanjay Patel bb789381fc [InstCombine] fix and enhance udiv/urem narrowing
There are 3 small independent changes here:

  1. Account for multiple uses in the pattern matching: avoid the transform if it increases the instruction count.
  2. Add a missing fold for the case where the numerator is the constant: http://rise4fun.com/Alive/E2p
  3. Enable all folds for vector types.

There's still one more potential change - use "shouldChangeType()" to keep from transforming to an illegal integer type.

Differential Revision: https://reviews.llvm.org/D36988

llvm-svn: 311726
2017-08-24 22:54:01 +00:00
Davide Italiano c78885818a [InstCombine] Fold branches with irrelevant conditions to a constant.
InstCombine folds instructions with irrelevant conditions to undef.
This, as Nuno confirmed is a bug.
(see https://bugs.llvm.org/show_bug.cgi?id=33409#c1 )

Given the original motivation for the change is that of removing an
USE, we now fold to false instead (which reaches the same goal
without undesired side effects).

Fixes PR33409.

Differential Revision:  https://reviews.llvm.org/D36975

llvm-svn: 311540
2017-08-23 09:14:37 +00:00
Craig Topper a85f86225a [InstCombine] Remove unused argument. NFC
llvm-svn: 311529
2017-08-23 05:46:09 +00:00
Craig Topper a94069fb4c [InstCombine] Replace a simple matcher with a plain old dyn_cast. NFC
llvm-svn: 311528
2017-08-23 05:46:08 +00:00
Craig Topper 524c44f74e [InstCombine] Remove an unnecessary dyn_cast to Instruction and a switch over two opcodes. Just dyn_cast to the specific instruction classes individually. NFC
Change the helper methods to take the more specific class as well.

llvm-svn: 311527
2017-08-23 05:46:07 +00:00
Craig Topper ec4b82571c [InstCombine] Remove check for sext of vector icmp from shouldOptimizeCast
Looks like for 'and' and 'or' we end up performing at least some of the transformations this is bocking in a round about way anyway.

For 'and sext(cmp1), sext(cmp2) we end up later turning it into 'select cmp1, sext(cmp2), 0'. Then we optimize that back to sext (and cmp1, cmp2). This is the same result we would have gotten if shouldOptimizeCast hadn't blocked it. We do something analogous for 'or'.

With this patch we allow that transformation to happen directly in foldCastedBitwiseLogic. And we now support the same thing for 'xor'. This is definitely opening up many other cases, but since we already went around it for some cases hopefully it's ok.

Differential Revision: https://reviews.llvm.org/D36213

llvm-svn: 311508
2017-08-22 23:40:15 +00:00
Craig Topper 775ffcc8f5 [InstCombine] Move the checks for pointer types in getMaskedTypeForICmpPair earlier in the function
I don't think there's any reason to have them scattered about and on all 4 operands. We already have an early check that both compares must be the same type. And within a given compare the LHS and RHS must have the same type. Beyond that I don't think there's anyway this function returns anything valid for pointer types. So let's just return early and be done with it.

Differential Revision: https://reviews.llvm.org/D36561

llvm-svn: 311383
2017-08-21 21:00:45 +00:00
Craig Topper 74177e1ed1 [InstCombine] Teach foldSelectICmpAnd to recognize a (icmp slt X, 0) and (icmp sgt X, -1) as equivalent to an and with the sign bit of the truncated type
This is similar to what was already done in foldSelectICmpAndOr. Ultimately I'd like to see if we can call foldSelectICmpAnd from foldSelectIntoOp if we detect a power of 2 constant. This would allow us to remove foldSelectICmpAndOr entirely.

Differential Revision: https://reviews.llvm.org/D36498

llvm-svn: 311362
2017-08-21 19:02:06 +00:00
Craig Topper cc255bcd77 [InstCombine] Fix a weakness in canEvaluateZExtd around 'and' instructions
Summary:
If the bitsToClear from the LHS of an 'and' comes back non-zero, but all of those bits are known zero on the RHS, we can reset bitsToClear.

Without this, the 'or' in the modified test case blocks the transform because it has non-zero bits in its RHS in those bits.

Reviewers: spatel, majnemer, davide

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36944

llvm-svn: 311343
2017-08-21 16:04:11 +00:00
Amjad Aboud 86111c6696 [InstCombine] Teach canEvaluateTruncated to handle arithmetic shift (including those with vector splat shift amount)
Differential Revision: https://reviews.llvm.org/D36784

llvm-svn: 311050
2017-08-16 22:42:38 +00:00
Craig Topper 882f29630b [InstCombine] Make folding (X >s -1) ? C1 : C2 --> ((X >>s 31) & (C2 - C1)) + C1 support splat vectors
This also uses decomposeBitTestICmp to decode the compare.

Differential Revision: https://reviews.llvm.org/D36781

llvm-svn: 311044
2017-08-16 21:52:07 +00:00
Craig Topper 0a1a276d91 [InstCombine] Teach canEvaluateZExtd and canEvaluateTruncated to handle vector shifts with splat shift amount
We were only allowing ConstantInt before. This patch allows splat of ConstantInt too.

Differential Revision: https://reviews.llvm.org/D36763

llvm-svn: 310970
2017-08-15 22:48:41 +00:00
Amjad Aboud 0464c5d958 [InstCombine] Added support for (X >>s C) << C --> X & (-1 << C)
Differential Revision: https://reviews.llvm.org/D36743

llvm-svn: 310949
2017-08-15 19:33:14 +00:00
Sanjay Patel f69b7d5c93 [InstCombine] sink sext after ashr
Narrow ops are better for bit-tracking, and in the case of vectors,
may enable better codegen.

As the trunc test shows, this can allow follow-on simplifications.

There's a block of code in visitTrunc that deals with shifted ops
with FIXME comments. It may be possible to remove some of that now,
but I want to make sure there are no problems with this step first.

http://rise4fun.com/Alive/Y3a

Name: hoist_ashr_ahead_of_sext_1
  %s = sext i8 %x to i32
  %r = ashr i32 %s, 3  ; shift value is < than source bit width
  =>
  %a = ashr i8 %x, 3
  %r = sext i8 %a to i32
  
Name: hoist_ashr_ahead_of_sext_2
  %s = sext i8 %x to i32
  %r = ashr i32 %s, 8  ; shift value is >= than source bit width
  =>
  %a = ashr i8 %x, 7   ; so clamp this shift value
  %r = sext i8 %a to i32
  
Name: junc_the_trunc  
  %a = sext i16 %v to i32
  %s = ashr i32 %a, 18
  %t = trunc i32 %s to i16
  =>
  %t = ashr i16 %v, 15
llvm-svn: 310942
2017-08-15 18:25:52 +00:00
Reid Kleckner 18728822d2 Remove checks for debug info intrinsics in use lists, NFC
These haven't done anything since debug info intrinsics stopped
appearing in Value use lists in 2014.

llvm-svn: 310892
2017-08-14 22:10:54 +00:00
Craig Topper 0aa3a19512 Recommit r310869, "[InstSimplify][InstCombine] Modify the interface of decomposeBitTestICmp and use it in the InstSimplify"
This recommits r310869, with the moved files and no extra changes.

Original commit message:

This addresses a fixme in InstSimplify about using decomposeBitTest. This also fixes InstSimplify to handle ugt and ult compares too.

I've modified the interface a little to return only the APInt version of the mask that InstSimplify needs. InstCombine now has a small wrapper routine to create a Constant out of it. I've also dropped the returning of 0 since InstSimplify doesn't need that. So InstCombine creates a zero constant itself.

I also had to make decomposeBitTest support vectors since InstSimplify needs that.

As InstSimplify can't use something from the Transforms library, I've moved the CmpInstAnalysis code to the Analysis library.

Differential Revision: https://reviews.llvm.org/D36593

llvm-svn: 310889
2017-08-14 21:39:51 +00:00
Craig Topper 69fa8e0d99 Revert r310869 "[InstSimplify][InstCombine] Modify the interface of decomposeBitTestICmp and use it in the InstSimplify"
Failed to add the two files that moved. And then added an extra change I didn't mean to while trying to fix that. Reverting everything.

llvm-svn: 310873
2017-08-14 19:09:32 +00:00
Craig Topper 2f0b450666 [InstSimplify][InstCombine] Modify the interface of decomposeBitTestICmp and use it in the InstSimplify
This addresses a fixme in InstSimplify about using decomposeBitTest. This also fixes InstSimplify to handle ugt and ult compares too.

I've modified the interface a little to return only the APInt version of the mask that InstSimplify needs. InstCombine now has a small wrapper routine to create a Constant out of it. I've also dropped the returning of 0 since InstSimplify doesn't need that. So InstCombine creates a zero constant itself.

I also had to make decomposeBitTest support vectors since InstSimplify needs that.

As InstSimplify can't use something from the Transforms library, I've moved the CmpInstAnalysis code to the Analysis library.

Differential Revision: https://reviews.llvm.org/D36593

llvm-svn: 310869
2017-08-14 18:49:42 +00:00
Craig Topper f720099007 [InstCombine] Simplify and inline FoldOrWithConstants/FoldXorWithConstants
Summary:
These functions were overly complicated. The body of this function was rechecking for an And operation to find the constant, but we already knew we were looking at two Ands ORed together and the pieces are in variables. We already had earlier nearby code that checked for ConstantInts. So just inline the remaining parts into the earlier code.

Next step is to use m_APInt instead of ConstantInt.

Reviewers: spatel, efriedma, davide, majnemer

Reviewed By: spatel

Subscribers: zzheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D36439

llvm-svn: 310806
2017-08-14 00:04:21 +00:00
Craig Topper 9a6110b2d3 [InstCombine] Make (X|C1)^C2 -> X^(C1^C2) iff X&~C1 == 0 work for splat vectors
This also corrects the description to match what was actually implemented. The old comment said X^(C1|C2), but it implemented X^((C1|C2)&~(C1&C2)). I believe ((C1|C2)&~(C1&C2)) is equivalent to (C1^C2).

Differential Revision: https://reviews.llvm.org/D36505

llvm-svn: 310658
2017-08-10 20:35:34 +00:00
Craig Topper 57b4d8646b [InstCombine] Fix a crash in getSelectCondition if we happen to have two inverse vectors of i1 constants.
We used to try to truncate the constant vector to vXi1, but if it's already i1 this would fail. Instead we now use IRBuilder::getZExtOrTrunc which should check the type and only create a trunc if needed. I believe this should trigger constant folding in the IRBuilder and ultimately do the same thing just with the additional type check.

llvm-svn: 310639
2017-08-10 17:48:14 +00:00
Craig Topper cd13ebca5f [InstCombine] Add a DEBUG_COUNTER to InstCombine to limit how many instructions are visited for debug
Sometimes it would be nice to stop InstCombine mid way through its combining to see the current IR. By using a debug counter we can place an upper limit on how many instructions to process.

This will also allow skipping the first X combines, but that has the potential to change later combines since earlier canonicalizations might have been skipped.

Differential Revision: https://reviews.llvm.org/D36553

llvm-svn: 310638
2017-08-10 17:48:12 +00:00
Sanjay Patel c50e55d0e6 [InstCombine] narrow rotate left/right patterns to eliminate zext/trunc (PR34046)
I couldn't find any smaller folds to help the cases in:
https://bugs.llvm.org/show_bug.cgi?id=34046
after:
rL310141

The truncated rotate-by-variable patterns elude all of the existing transforms because 
of multiple uses and knowledge about demanded bits and knownbits that doesn't exist 
without the whole pattern. So we need an unfortunately large pattern match. But by 
simplifying this pattern in IR, the backend is already able to generate 
rolb/rolw/rorb/rorw for x86 using its existing rotate matching logic (although
there is a likely extraneous 'and' of the rotate amount). 

Note that rotate-by-constant doesn't have this problem - smaller folds should already 
produce the narrow IR ops.

Differential Revision: https://reviews.llvm.org/D36395

llvm-svn: 310509
2017-08-09 18:37:41 +00:00
Craig Topper 5706c01c0b [InstCombine] Use regular dyn_cast instead of a matcher for a simple case. NFC
llvm-svn: 310446
2017-08-09 06:17:48 +00:00
Craig Topper 364359e4fc [InstCombine] Support pulling left shifts through a subtract with constant LHS
We already support pulling through an add with constant RHS. We can do the same for subtract.

Differential Revision: https://reviews.llvm.org/D36443

llvm-svn: 310407
2017-08-08 20:14:11 +00:00
Craig Topper 8e351e9018 [InstCombine] Cast to BinaryOperator earlier in foldSelectIntoOp to simplify the code.
We no longer need the explicit operand count check or the later dynamic cast.

llvm-svn: 310339
2017-08-08 06:19:24 +00:00
Aaron Ballman 428f0fe910 Removing an unused variable that was missed with the refactoring in r310272; NFC.
llvm-svn: 310285
2017-08-07 19:26:17 +00:00
Craig Topper 7091a743b4 [InstCombine] Support (X | C1) & C2 --> (X & C2^(C1&C2)) | (C1&C2) for vector splats
Note the original code I deleted incorrectly listed this as (X | C1) & C2 --> (X & C2^(C1&C2)) | C1 Which is only valid if C1 is a subset of C2. This relied on SimplifyDemandedBits to remove any extra bits from C1 before we got to that code.

My new implementation avoids relying on that behavior so that it can be naively verified with alive.

Differential Revision: https://reviews.llvm.org/D36384

llvm-svn: 310272
2017-08-07 18:10:39 +00:00
Craig Topper 576fb91aef [InstCombine] Remove shift handling from OptAndOp.
Summary: This is all handled by SimplifyDemandedBits.

Reviewers: spatel, davide

Reviewed By: davide

Subscribers: davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D36382

llvm-svn: 310234
2017-08-06 23:30:49 +00:00
Craig Topper a1693a2ed3 [InstCombine] Support (X ^ C1) & C2 --> (X & C2) ^ (C1&C2) for vector splats.
llvm-svn: 310233
2017-08-06 23:11:49 +00:00
Craig Topper 9cbdbefd0f [InstCombine] Support '(C - X) ^ signmask -> (C + signmask - X)' and '(X + C) ^ signmask -> (X + C + signmask)' for vector splats.
llvm-svn: 310232
2017-08-06 22:17:21 +00:00
Craig Topper b5bf016015 [InstCombine] Support ~(c-X) --> X+(-c-1) and ~(X-c) --> (-c-1)-X for splat vectors.
llvm-svn: 310195
2017-08-06 06:28:41 +00:00
Craig Topper 9ffda5ab86 [InstCombine] Fold (C - X) ^ signmask -> (C + signmask - X).
llvm-svn: 310186
2017-08-05 20:00:44 +00:00
Craig Topper 65dd32afbc [InstCombine] Teach the code that pulls logical operators through constant shifts to handle vector splats too.
llvm-svn: 310185
2017-08-05 20:00:42 +00:00
Craig Topper 1bbcab9ca5 [InstCombine] Support vector splats in foldSelectICmpAnd.
Unfortunately, it looks like there's some other missed optimizations in the generated code for some of these cases. I'll try to look at some of those next.

llvm-svn: 310184
2017-08-05 20:00:41 +00:00
Sanjay Patel 94da1de1ce [InstCombine] refactor trunc(binop) transforms; NFCI
In addition to moving the shift transforms over, we may want to
detect too-wide rotate patterns here (PR34046). 

llvm-svn: 310181
2017-08-05 15:19:18 +00:00
Craig Topper fc5283092b [InstCombine] In foldSelectICmpAnd, if we need to to truncate from the 'and' type to the 'select' type, do it after shifting right instead of just bailing.
Previously we were always trying to emit the zext or truncate before any shift. This meant if the 'and' mask was larger than the size of the truncate we would skip the transformation.

Now we shift the result of the and right first leaving the bit within the range of the truncate.

This matches what we are doing in foldSelectICmpAndOr for the same problem.

llvm-svn: 310159
2017-08-05 01:45:17 +00:00
Sanjay Patel e12d734be3 [InstCombine] narrow truncated add/sub/mul with constant
Name: narrow_sub
  %sub = sub i32 C1, %x
  %r = trunc i32 %sub to i8
  =>  
  %xn = trunc i32 %x to i8
  %narrowC = trunc i32 C1 to i8
  %r = sub i8 %narrowC, %xn
 
Name: narrow_add
  %add = add i32 %x, C1
  %r = trunc i32 %add to i8
  =>  
  %xn = trunc i32 %x to i8
  %narrowC = trunc i32 C1 to i8
  %r = add i8 %xn, %narrowC
  
Name: narrow_mul
  %mul = mul i32 %x, C1
  %r = trunc i32 %mul to i8
  =>  
  %xn = trunc i32 %x to i8
  %narrowC = trunc i32 C1 to i8
  %r = mul i8 %xn, %narrowC


http://rise4fun.com/Alive/QpS

This doesn't solve PR34046 (failure to recognize rotate):
https://bugs.llvm.org/show_bug.cgi?id=34046
...but it reduces an extra complication in the description examples 
to a form that we can more easily match.

llvm-svn: 310141
2017-08-04 22:30:34 +00:00
Benjamin Kramer bda212a65d [InstCombine] Fold single-use variable into assert.
Avoids unused variable warnings in Release builds. No functional change.

llvm-svn: 310064
2017-08-04 16:08:41 +00:00
Craig Topper 760ff6ee87 [InstCombine] Remove the (not (sext)) case from foldBoolSextMaskToSelect and inline the remaining code to match visitOr
Summary:
The (not (sext)) case is really (xor (sext), -1) which should have been simplified to (sext (xor, 1)) before we got here. So we shouldn't need to handle it.

With that taken care of we only need to two cases so don't need the swap anymore. This makes us in sync with the equivalent code in visitOr so inline this to match.

Reviewers: spatel, eli.friedman, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36240

llvm-svn: 310063
2017-08-04 16:07:20 +00:00
Craig Topper 3b74a68cc7 [InstCombine] Use ConstantInt::getFalse to reduce some code. NFC
llvm-svn: 310062
2017-08-04 16:07:18 +00:00
Sanjay Patel 79e7f6b3e3 [InstCombine] narrow lshr with constant
Name: narrow_shift
Pre: C1 < 8
%zx = zext i8 %x to i32
%l = lshr i32 %zx, C1
  =>  
%narrowC = trunc i32 C1 to i8
%ns = lshr i8 %x, %narrowC
%l = zext i8 %ns to i32

http://rise4fun.com/Alive/jIV

This isn't directly applicable to PR34046 as written, but we
need to have more narrowing folds like this to be sure that
rotate patterns are recognized.

llvm-svn: 310060
2017-08-04 15:42:47 +00:00
Nikolai Bozhenov 1545eb3408 [InstCombine] Canonicalize clamp of float types to minmax in fast mode.
Summary:
This commit allows matchSelectPattern to recognize clamp of float
arguments in the presence of FMF the same way as already done for
integers.

This case is a little different though. With integers, given the
min/max pattern is recognized, DAGBuilder starts selecting MIN/MAX
"automatically". That is not the case for float, because for them only
full FMINNAN/FMINNUM/FMAXNAN/FMAXNUM ISD nodes exist and they do care
about NaNs. On the other hand, some backends (e.g. X86) have only
FMIN/FMAX nodes that do not care about NaNS and the former NAN/NUM
nodes are illegal thus selection is not happening. So I decided to do
such kind of transformation in IR (InstCombiner) instead of
complicating the logic in the backend.

Reviewers: spatel, jmolloy, majnemer, efriedma, craig.topper

Reviewed By: efriedma

Subscribers: hiraditya, javed.absar, n.bozhenov, llvm-commits

Patch by Andrei Elovikov <andrei.elovikov@intel.com>

Differential Revision: https://reviews.llvm.org/D33186

llvm-svn: 310054
2017-08-04 12:22:17 +00:00
Craig Topper c2d3c631ff [InstCombine] Move the call to foldSelectICmpAnd into foldSelectInstWithICmp. NFCI
llvm-svn: 310025
2017-08-04 05:12:37 +00:00
Craig Topper a86ca08d26 [InstCombine] Remove unnecessary casts. NFC
We're calling an overload of getOpcode that already returns Instruction::CastOps.

llvm-svn: 310024
2017-08-04 05:12:35 +00:00
Craig Topper fc9bf50dee [InstCombine] Remove unnecessary temporary APInt. NFCI
llvm-svn: 309887
2017-08-02 21:05:40 +00:00
Craig Topper 4068e4eec5 [InstCombine] Remove explicit code for folding (xor(zext(cmp)), 1) and (xor(sext(cmp)), -1) to ext(!cmp).
As far as I can tell this should be handled by foldCastedBitwiseLogic which is called later in visitXor.

Differential Revision: https://reviews.llvm.org/D36214

llvm-svn: 309882
2017-08-02 20:30:27 +00:00
Craig Topper ae9b87d10c [InstCombine] Support sext in foldLogicCastConstant
This adds support for sext in foldLogicCastConstant. This is a prerequisite for D36214.

Differential Revision: https://reviews.llvm.org/D36234

llvm-svn: 309880
2017-08-02 20:25:56 +00:00
Chad Rosier dfd1de687d [Value Tracking] Default argument to true and rename accordingly. NFC.
IMHO this is a bit more readable.

llvm-svn: 309739
2017-08-01 20:18:54 +00:00
Craig Topper 4d5050b5ba [InstCombine] Remove explicit check for impossible condition. Replace with assert
Summary:
As far as I can tell the earlier call getLimitedValue will guaranteed ShiftAmt is saturated to BitWidth-1 preventing it from ever being equal or greater than BitWidth.

At one point in the past the getLimitedValue call was only passed BitWidth not BitWidth - 1. This would have allowed the equality case to get here. And in fact this check was initially added as just BitWidth == ShiftAmt, but was changed shortly after to include > which should have never been possible.

Reviewers: spatel, majnemer, davide

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36123

llvm-svn: 309690
2017-08-01 15:10:25 +00:00
Sanjay Patel dac0ab272c [InstCombine] allow mask hoisting transform for vector types
llvm-svn: 309627
2017-07-31 21:01:53 +00:00
Craig Topper 317a51e886 [X86][InstCombine] Add some simplifications for BZHI intrinsics
This intrinsic clears the upper bits starting at a specified index. If the index is a constant we can do some simplifications.

This could be in InstSimplify, but we don't handle any target specific intrinsics there today.

Differential Revision: https://reviews.llvm.org/D36069

llvm-svn: 309604
2017-07-31 18:52:15 +00:00
Craig Topper 8324003818 [X86][InstCombine] Add basic simplification support for BEXTR/BEXTRI intrinsics.
This patch adds simplification support for the BEXTR/BEXTRI intrinsics to match gcc. This only supports cases that fold to 0 or can be fully constant folded. Theoretically we could support converting to AND if the shift part is unused or to only a shift if the mask doesn't modify any bits after an equivalent shl. gcc doesn't do these transformations either.

I put this in InstCombine, but it could be done in InstSimplify. It would be the first target specific intrinsic in InstSimplify.

Differential Revision: https://reviews.llvm.org/D36063

llvm-svn: 309603
2017-07-31 18:52:13 +00:00
Hiroshi Yamauchi 60855214c2 [InstCombine] Simplify pointer difference subtractions (GEP-GEP) where GEPs have other uses and one non-constant index
Summary:
Pointer difference simplifications currently happen only if input GEPs don't have other uses or their indexes are all constants, to avoid duplicating indexing arithmetic.

This patch enables cases with exactly one non-constant index among input GEPs to happen where there is no duplicated arithmetic or code size increase even if input GEPs have other uses.

For example, this patch allows "(&A[42][i]-&A[42][0])" --> "i", which didn't happen previously, if the input GEP(s) have other uses.

Reviewers: sanjoy, bkramer

Reviewed By: sanjoy

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D35499

llvm-svn: 309304
2017-07-27 18:27:11 +00:00
Hiroshi Yamauchi 0445e31c88 Fix a comment (test commit).
llvm-svn: 309192
2017-07-26 21:54:43 +00:00
Adam Nemet ea06e6e865 Migrate SimplifyLibCalls to new OptimizationRemarkEmitter
Summary:
This changes SimplifyLibCalls to use the new OptimizationRemarkEmitter
API.

In fact, as SimplifyLibCalls is only ever called via InstCombine,
(as far as I can tell) the OptimizationRemarkEmitter is added there,
and then passed through to SimplifyLibCalls later.

I have avoided changing any remark text.

This closes PR33787

Patch by Sam Elliott!

Reviewers: anemet, davide

Reviewed By: anemet

Subscribers: davide, mehdi_amini, eraman, fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D35608

llvm-svn: 309158
2017-07-26 19:03:18 +00:00
Wei Mi fc0e245464 Disable loop unswitching for some patterns containing equality comparison with undef.
This is a workaround for the bug described in PR31652 and
http://lists.llvm.org/pipermail/llvm-dev/2017-July/115497.html. The temporary
solution is to add a function EqualityPropUnSafe. In EqualityPropUnSafe, for
some simple patterns we can know the equality comparison may contains undef,
so we regard such comparison as unsafe and will not do loop-unswitching for
them. We also need to disable the select simplification when one of select
operand is undef and its result feeds into equality comparison.

The patch cannot clear the safety issue caused by the bug, but it can suppress
the issue from happening to some extent.

Differential Revision: https://reviews.llvm.org/D35811

llvm-svn: 309059
2017-07-25 23:37:17 +00:00
Weiming Zhao 984f1dc338 Fix DebugLoc propagation for unreachable LoadInst
Summary: Currently, when GVN creates a load and when InstCombine creates a new store for unreachable Load, the DebugLoc info gets lost.

Reviewers: dberlin, davide, aprantl

Reviewed By: aprantl

Subscribers: davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D34639

llvm-svn: 308404
2017-07-19 01:27:24 +00:00
Davide Italiano 579064e2c1 [InstCombine] Don't violate dominance when replacing instructions.
Differential Revision:  https://reviews.llvm.org/D35376

llvm-svn: 308144
2017-07-16 18:56:30 +00:00
Craig Topper 2072aca51c [InstCombine] Move (0 - x) & 1 --> x & 1 to SimplifyDemandedUseBits.
This removes a dedicated matcher and allows us to support more than just an AND masking the lower bit.

llvm-svn: 308124
2017-07-16 05:37:58 +00:00
Craig Topper d918d5b36b [InstCombine] Improve the expansion in SimplifyUsingDistributiveLaws to handle cases where one side doesn't simplify, but the other side resolves to an identity value
Summary:
If one side simplifies to the identity value for inner opcode, we can replace the value with just the operation that can't be simplified.

I've removed a couple now unneeded special cases in visitAnd and visitOr. There are probably other cases I missed.

Reviewers: spatel, majnemer, hfinkel, dberlin

Reviewed By: spatel

Subscribers: grandinj, llvm-commits, spatel

Differential Revision: https://reviews.llvm.org/D35451

llvm-svn: 308111
2017-07-15 21:49:49 +00:00
Sanjay Patel 3437ee2740 [InstCombine] improve (1 << x) & 1 --> zext(x == 0) folding
1. Add a one-use check to prevent increasing instruction count.
2. Generalize the pattern matching to include vector types.

llvm-svn: 308105
2017-07-15 17:26:01 +00:00
Sanjay Patel 55b9f88ecc [InstCombine] allow (0 - x) & 1 --> x & 1 for vectors
llvm-svn: 308098
2017-07-15 15:29:47 +00:00
Sanjay Patel 27339133a7 [InstCombine] remove dead code/tests; NFCI
These patterns and tests were added to InstSimplify with:
https://reviews.llvm.org/rL303004

llvm-svn: 308096
2017-07-15 15:01:33 +00:00
Sanjay Patel 3f4db3ea97 [InstCombine] convert bitwise (in)equality checks to logical ops (PR32401)
As discussed in:
https://bugs.llvm.org/show_bug.cgi?id=32401

we have a backend transform to undo this:
https://reviews.llvm.org/rL299542

when it's likely that the xor version leads to better codegen, but we want 
this form in IR for better analysis and simplification potential.

llvm-svn: 308031
2017-07-14 15:09:49 +00:00
Konstantin Zhuravlyov bb80d3e1d3 Enhance synchscope representation
OpenCL 2.0 introduces the notion of memory scopes in atomic operations to
  global and local memory. These scopes restrict how synchronization is
  achieved, which can result in improved performance.

  This change extends existing notion of synchronization scopes in LLVM to
  support arbitrary scopes expressed as target-specific strings, in addition to
  the already defined scopes (single thread, system).

  The LLVM IR and MIR syntax for expressing synchronization scopes has changed
  to use *syncscope("<scope>")*, where <scope> can be "singlethread" (this
  replaces *singlethread* keyword), or a target-specific name. As before, if
  the scope is not specified, it defaults to CrossThread/System scope.

  Implementation details:
    - Mapping from synchronization scope name/string to synchronization scope id
      is stored in LLVM context;
    - CrossThread/System and SingleThread scopes are pre-defined to efficiently
      check for known scopes without comparing strings;
    - Synchronization scope names are stored in SYNC_SCOPE_NAMES_BLOCK in
      the bitcode.

Differential Revision: https://reviews.llvm.org/D21723

llvm-svn: 307722
2017-07-11 22:23:00 +00:00
Hiroshi Inoue 0ca79dcf4b fix typos in comments; NFC
llvm-svn: 307626
2017-07-11 06:04:59 +00:00
Serge Guelton f6329ec2e9 Fix invalid cast in instcombine UMul/ZExt idiom
Fixes https://bugs.llvm.org/show_bug.cgi?id=25454

Do not assume IRBuilder creates Instruction where it can create Value.
Do not assume idiom operands are constant, leave generalisation ot the IRBuilder.

Differential Revision: https://reviews.llvm.org/D35114

llvm-svn: 307554
2017-07-10 16:51:40 +00:00
Craig Topper fde4723ebe [IR] Add Type::isIntOrIntVectorTy(unsigned) similar to the existing isIntegerTy(unsigned), but also works for vectors.
llvm-svn: 307492
2017-07-09 07:04:03 +00:00
Craig Topper 95d2347ae1 [IR] Make use of Type::isPtrOrPtrVectorTy/isIntOrIntVectorTy/isFPOrFPVectorTy to shorten code. NFC
llvm-svn: 307491
2017-07-09 07:04:00 +00:00
Craig Topper e79b3e7d9a [InstCombine] Speculatively implement a fix for what might be the root cause of PR33721 by making sure that we have integer types before doing select C, -1, 0 -> sext C to int
I recently changed m_One and m_AllOnes to use Constant::isOneValue/isAllOnesValue which work on floating point values too. The original implementation looked specifically for ConstantInt scalars and splats. So I'm guessing we are accidentally trying to issue sext/zexts on floating point types now.

Hopefully I figure out how to reproduce the failure from the PR soon.

llvm-svn: 307486
2017-07-09 03:25:17 +00:00
Craig Topper bb4069e439 [InstCombine] Make InstCombine's IRBuilder be passed by reference everywhere
Previously the InstCombiner class contained a pointer to an IR builder that had been passed to the constructor. Sometimes this would be passed to helper functions as either a pointer or the pointer would be dereferenced to be passed by reference.

This patch makes it a reference everywhere including the InstCombiner class itself so there is more inconsistency. This a large, but mechanical patch. I've done very minimal formatting changes on it despite what clang-format wanted to do.

llvm-svn: 307451
2017-07-07 23:16:26 +00:00
Craig Topper cb22039bee [InstCombine] No need to pass DataLayout to helper functions if we're passing the InstCombiner object. We can just ask it for the DataLayout. NFC
llvm-svn: 307333
2017-07-06 23:18:43 +00:00
Craig Topper 4853c4304b [InstCombine] Remove unused arguments from some helper functions. NFC
llvm-svn: 307332
2017-07-06 23:18:42 +00:00
Craig Topper 2bb9f0f620 [InstCombine] Change a couple helper functions to only take the IRBuilder as an argument and not the whole InstCombiner object. NFC
llvm-svn: 307331
2017-07-06 23:18:41 +00:00
Craig Topper e9bf7ebacf [InstCombine] Remove include of DIBuilder.h and Dwarf.h as they don't appear to be necessary.
llvm-svn: 307295
2017-07-06 18:47:47 +00:00
Craig Topper ca2c87653c [Constants] Replace calls to ConstantInt::equalsInt(0)/equalsInt(1) with isZero and isOne. NFCI
llvm-svn: 307293
2017-07-06 18:39:49 +00:00
Craig Topper 79ab643da8 [Constants] If we already have a ConstantInt*, prefer to use isZero/isOne/isMinusOne instead of isNullValue/isOneValue/isAllOnesValue inherited from Constant. NFCI
Going through the Constant methods requires redetermining that the Constant is a ConstantInt and then calling isZero/isOne/isMinusOne.

llvm-svn: 307292
2017-07-06 18:39:47 +00:00
Craig Topper 47c8f66997 [InstCombine] Remove Builder argument from InstCombiner::tryFactorization. NFC
Builder is already a member of the InstCombiner class so we can use it with passing it.

llvm-svn: 307290
2017-07-06 18:35:52 +00:00
Craig Topper 95e4142f94 [InstCombine] Change helper method to a file local static method. NFC
llvm-svn: 307275
2017-07-06 16:24:23 +00:00
Craig Topper fc42acef92 [InstCombine] Clarify comment to mention other transform that it does. NFC
llvm-svn: 307274
2017-07-06 16:24:22 +00:00
Craig Topper 22795de20a [InstCombine] Add single use checks to SimplifyBSwap to ensure we are really saving instructions
Bswap isn't a simple operation so we need to make sure we are really removing a call to it before doing these simplifications.

For the case when both LHS and RHS are bswaps I've allowed it to be moved if either LHS or RHS has a single use since that at least allows us to move it later where it might find another bswap to combine with and it decreases the use count on the other side so maybe the other user can be optimized.

Differential Revision: https://reviews.llvm.org/D34974

llvm-svn: 307273
2017-07-06 16:24:21 +00:00
Craig Topper 3e1909d797 [InstCombine] Don't create extra ConstantInt objects in foldSelectICmpAnd. NFCI
Instead just use APInt objects and only create a ConstantInt at the end if we need it for the Offset.

llvm-svn: 307270
2017-07-06 15:58:54 +00:00
Craig Topper cc418b656a [InstCombine] Use CmpInst::Predicate with m_Cmp instead of ICmpInst::Predicate. NFC
There isn't really an ICmpInst version so we're just accessing the CmpInst version through inheritance.

llvm-svn: 307199
2017-07-05 20:31:00 +00:00
Craig Topper 0f746c2793 [InstCombine] Add TODOs for a couple things that should maybe be in InstSimplify instead. NFC
llvm-svn: 307065
2017-07-04 06:50:48 +00:00
Craig Topper 8036970008 [InstCombine] Add a TODO for a probable missing single use check. NFC
Will try to fix it soon, but in case I forget.

llvm-svn: 307003
2017-07-03 05:54:16 +00:00
Craig Topper 766ce6e9cf [InstCombine] Support BITWISE_OP( BSWAP(x), CONSTANT ) -> BSWAP( BITWISE_OP(x, BSWAP(CONSTANT) ) ) for splat vectors.
llvm-svn: 307002
2017-07-03 05:54:15 +00:00
Craig Topper 32fce4d647 [InstCombine] Remove support for BITWISE_OP(CONSTANT, BSWAP(x)) -> BSWAP(OP(BSWAP(CONSTANT), x)).
Constants were already canonicalized to the right hand side before we got here.

llvm-svn: 307000
2017-07-03 05:54:13 +00:00
Craig Topper 1e4643a98e [InstCombine] Support BITWISE_OP(BSWAP(A),BSWAP(B))->BSWAP(BITWISE_OP(A, B)) for vectors.
llvm-svn: 306999
2017-07-03 05:54:13 +00:00
Craig Topper c6948c25cc [InstCombine] Remove an if that should have been guaranteed by the caller. Replace with an assert. NFC
llvm-svn: 306997
2017-07-03 05:54:11 +00:00
Simon Pilgrim df2657ac2d [InstCombine] Use m_BitReverse pattern match helper. NFCI.
llvm-svn: 306986
2017-07-02 16:31:16 +00:00
Sanjay Patel b51e072d35 [InstCombine] fix crash when folding cmp+bswap vector
We assumed the constant was a scalar when creating the replacement operand.

Also, improve tests for this fold and move the tests for this fold to their own file.
I'll move the related and missing tests to this file as a follow-up.  

llvm-svn: 306985
2017-07-02 16:05:11 +00:00
Sanjay Patel c3d5cf0bb7 [InstCombine] look through bswap/bitreverse for equality comparisons
I noticed this missed bswap optimization in the CGP memcmp() expansion, 
and then I saw that we don't have the fold in InstCombine.

Differential Revision: https://reviews.llvm.org/D34763

llvm-svn: 306980
2017-07-02 14:34:50 +00:00
Craig Topper f60ab47098 [InstCombine] Fold (a | b) ^ (~a | ~b) --> ~(a ^ b) and (a & b) ^ (~a & ~b) --> ~(a ^ b)
Summary:
I came across this while thinking about what would happen if one of the operands in this xor pattern was itself a inverted (A & ~B) ^ (~A & B)-> (A^B).

The patterns here assume that the (~a | ~b) will be demorganed to ~(a & b) first. Though I wonder if there's a multiple use case that would prevent the demorgan.

Reviewers: spatel

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34870

llvm-svn: 306967
2017-07-02 01:15:51 +00:00
Craig Topper bcf511c0da [InstCombine] Replace an unnecessary use of a matcher with just an isa and a cast. NFC
We aren't looking through any levels of IR here so I don't think we need the power of a matcher or the temporary variable it requires.

llvm-svn: 306885
2017-06-30 21:09:34 +00:00
Simon Pilgrim 77c3c5f9b8 [InstCombine] Add m_BitReverse pattern match helper. NFCI.
llvm-svn: 306860
2017-06-30 18:58:29 +00:00
Nikolai Bozhenov bde9b14c6f Revert of r306525: "Canonicalize clamp of float types to minmax"
llvm-svn: 306815
2017-06-30 10:39:09 +00:00
Craig Topper 880bf82685 [InstCombine] In foldXorToXor, move the commutable matcher from the LHS match to the RHS match. No meaningful change intended.
There are two conditions ORed here with similar checks and each contain two matches that must be true for the if to succeed. With the commutable match on the first half of the OR then both ifs basically have the same first part and only the second part distinguishs. With this change we move the commutable match to second half and make the first half unique.

This caused some tests to change because we now produce a commuted result, but this shouldn't matter in practice.

llvm-svn: 306800
2017-06-30 07:37:41 +00:00
Eric Christopher a95aac3751 Reduce indenting and clean up comparisons around sign bit.
llvm-svn: 306781
2017-06-30 01:57:48 +00:00
Eric Christopher 710c1c8faa Reduce the complexity of the signbit/branch test functions.
llvm-svn: 306779
2017-06-30 01:35:31 +00:00
Craig Topper 798a19ab8e [InstCombine] In visitXor, use m_Not on the instruction itself instead of looking for all ones in Op1. This is consistent with 3 other not checks before this one. NFCI
llvm-svn: 306617
2017-06-29 00:07:08 +00:00
Keno Fischer a236dae5d1 [InstCombine] Retain TBAA when narrowing memory accesses
Summary:
As discussed on the mailing list it is legal to propagate TBAA to loads/stores
from/to smaller regions of a larger load tagged with TBAA. Do so for
(load->extractvalue)=>(gep->load) and similar foldings.

Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D31954

llvm-svn: 306615
2017-06-28 23:36:40 +00:00
Sanjay Patel 4e96f19052 [InstCombine] use local variable to reduce code; NFCI
llvm-svn: 306560
2017-06-28 16:39:06 +00:00
Nikolai Bozhenov b01e6b5a52 [InstCombine] Canonicalize clamp of float types to minmax in fast mode.
Summary:
This commit allows matchSelectPattern to recognize clamp of float
arguments in the presence of FMF the same way as already done for
integers.

This case is a little different though. With integers, given the
min/max pattern is recognized, DAGBuilder starts selecting MIN/MAX
"automatically". That is not the case for float, because for them only
full FMINNAN/FMINNUM/FMAXNAN/FMAXNUM ISD nodes exist and they do care
about NaNs. On the other hand, some backends (e.g. X86) have only
FMIN/FMAX nodes that do not care about NaNS and the former NAN/NUM
nodes are illegal thus selection is not happening. So I decided to do
such kind of transformation in IR (InstCombiner) instead of
complicating the logic in the backend.

Reviewers: spatel, jmolloy, majnemer, efriedma, craig.topper

Reviewed By: efriedma

Subscribers: hiraditya, javed.absar, n.bozhenov, llvm-commits

Patch by Andrei Elovikov <andrei.elovikov@intel.com>

Differential Revision: https://reviews.llvm.org/D33186

llvm-svn: 306525
2017-06-28 09:26:20 +00:00
Craig Topper 5fe0197622 [InstCombine] Propagate nsw flag when turning mul by pow2 into shift when the constant is a vector splat or the scalar bit width is larger than 64-bits
The check to see if we can propagate the nsw flag used m_ConstantInt(uint64_t*&) which doesn't work with splat vectors and has a restriction that the bitwidth of the ConstantInt must be 64-bits are less.

This patch changes it to use m_APInt to remove both these issues

Differential Revision: https://reviews.llvm.org/D34699

llvm-svn: 306457
2017-06-27 19:57:53 +00:00
Sanjay Patel 7227276d41 [InstCombine] canonicalize icmp predicate feeding select
This canonicalization was suggested in D33172 as a way to make InstCombine behavior more uniform. 
We have this transform for icmp+br, so unless there's some reason that icmp+select should be 
treated differently, we should do the same thing here.

The benefit comes from increasing the chances of creating identical instructions. This is shown in
the tests in logical-select.ll (PR32791). InstCombine doesn't fold those directly, but EarlyCSE 
can simplify the identical cmps, and then InstCombine can fold the selects together.

The possible regression for the tests in select.ll raises questions about poison/undef:
http://lists.llvm.org/pipermail/llvm-dev/2017-May/113261.html

...but that transform is just as likely to be triggered by this canonicalization as it is to be 
missed, so we're just pointing out a commutation deficiency in the pattern matching:
https://reviews.llvm.org/rL228409

Differential Revision: https://reviews.llvm.org/D34242

llvm-svn: 306435
2017-06-27 17:53:22 +00:00
Chandler Carruth 2abb65ae11 [InstCombine] Factor the logic for propagating !nonnull and !range
metadata out of InstCombine and into helpers.

NFC, this just exposes the logic used by InstCombine when propagating
metadata from one load instruction to another. The plan is to use this
in SROA to address PR32902.

If anyone has better ideas about how to factor this or name variables,
I'm all ears, but this seemed like a pretty good start and lets us make
progress on the PR.

This is based on a patch by Ariel Ben-Yehuda (D34285).

llvm-svn: 306267
2017-06-26 03:31:31 +00:00
Sanjay Patel 2f3ead7adc [InstCombine] add (sext i1 X), 1 --> zext (not X)
http://rise4fun.com/Alive/i8Q

A narrow bitwise logic op is obviously better than math for value tracking, 
and zext is better than sext. Typically, the 'not' will be folded into an 
icmp predicate.

The IR difference would even survive through codegen for x86, so we would see 
worse code:

https://godbolt.org/g/C14HMF

one_or_zero(int, int):                      # @one_or_zero(int, int)
        xorl    %eax, %eax
        cmpl    %esi, %edi
        setle   %al
        retq

one_or_zero_alt(int, int):                  # @one_or_zero_alt(int, int)
        xorl    %ecx, %ecx
        cmpl    %esi, %edi
        setg    %cl
        movl    $1, %eax
        subl    %ecx, %eax
        retq

llvm-svn: 306243
2017-06-25 14:15:28 +00:00
Craig Topper 7b66ffe875 [ValueTracking][InstCombine] Use m_Shr instead m_CombineOr(m_LShr, m_AShr). NFC
llvm-svn: 306205
2017-06-24 06:24:04 +00:00
Craig Topper 72ee6945af [Analysis][Transforms] Use commutable matchers instead of m_CombineOr in a few places. NFC
llvm-svn: 306204
2017-06-24 06:24:01 +00:00
Vitaly Buka df19ad456e [InstCombine] Don't replace allocas with smaller globals
Summary:
InstCombine replaces large allocas with small globals consts causing buffer overflows
on valid code, see PR33372.

This fix permits this optimization only if the global is dereference for alloca size.

Fixes PR33372

Reviewers: eugenis, majnemer, chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34311

llvm-svn: 306194
2017-06-24 01:35:19 +00:00
Anna Thomas d67165c93c [InstCombine] Recognize and simplify three way comparison idioms
Summary:
Many languages have a three way comparison idiom where comparing two values
produces not a boolean, but a tri-state value. Typical values (e.g. as used in
the lcmp/fcmp bytecodes from Java) are -1 for less than, 0 for equality, and +1
for greater than.

We actually do a great job already of converting three way comparisons into
binary comparisons when the result produced has one a single use. Unfortunately,
such values can have more than one use, and in that case, our existing
optimizations break down.

The patch adds a peephole which converts a three-way compare + test idiom into a
binary comparison on the original inputs. It focused on replacing the test on
the result of the three way compare and does nothing about removing the three
way compare itself. That's left to other optimizations (which do actually kick
in commonly.)
We currently recognize one idiom on signed integer compare. In the future, we
plan to recognize and simplify other comparison idioms on
other signed/unsigned datatypes such as floats, vectors etc.

This is a resurrection of Philip Reames' original patch:
https://reviews.llvm.org/D19452

Reviewers: majnemer, apilipenko, reames, sanjoy, mkazantsev

Reviewed by: mkazantsev

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34278

llvm-svn: 306100
2017-06-23 13:41:45 +00:00
Craig Topper dffbbcb3fd [InstCombine] Teach foldSelectICmpAndOr to recognize (select (icmp slt (trunc (X)), 0), Y, (or Y, C2))
Summary:
InstCombine likes to turn (icmp eq (and X, C1), 0) into (icmp slt (trunc (X)), 0) sometimes. This breaks foldSelectICmpAndOr's ability to recognize (select (icmp eq (and X, C1), 0), Y, (or Y, C2))->(or (shl (and X, C1), C3), y).

This patch tries to recover this. I had to flip around some of the early out checks so that I could create a new And instruction during the compare processing without it possibly never getting used.

Reviewers: spatel, majnemer, davide

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34184

llvm-svn: 306029
2017-06-22 16:23:30 +00:00
Craig Topper 0de5e6a729 [InstCombine] Add one use checks to or/and->xnor folding
If the components of the and/or had multiple uses, this transform created an additional instruction.

This patch makes sure we remove one of the components.

Differential Revision: https://reviews.llvm.org/D34498

llvm-svn: 306027
2017-06-22 16:12:02 +00:00
Sanjay Patel d1e811979c [InstCombine] reverse bitcast + bitwise-logic canonicalization (PR33138)
There are 2 parts to this patch made simultaneously to avoid a regression.

We're reversing the canonicalization that moves bitwise vector ops before bitcasts. 
We're moving bitwise vector ops *after* bitcasts instead. That's the 1st and 3rd hunks 
of the patch. The motivation is that there's only one fold that currently depends on 
the existing canonicalization (see next), but there are many folds that would 
automatically benefit from the new canonicalization. 
PR33138 ( https://bugs.llvm.org/show_bug.cgi?id=33138 ) shows why/how we have these 
patterns in IR.

There's an or(and,andn) pattern that requires an adjustment in order to continue matching
to 'select' because the bitcast changes position. This match is unfortunately complicated 
because it requires 4 logic ops with optional bitcast and sext ops.

Test diffs:

  1. The bitcast.ll and bitcast-bigendian.ll changes show the most basic difference - 
     bitcast comes before logic.
  2. There are also tests with no diffs in bitcast.ll that verify that we're still doing 
     folds that were enabled by the previous canonicalization.
  3. icmp-xor-signbit.ll shows the payoff. We don't need to adjust existing icmp patterns 
     to look through bitcasts.
  4. logical-select.ll contains several tests for the or(and,andn) --> select fold to 
     verify that we are still handling those cases. The lone diff shows the movement of 
     the bitcast from the new canonicalization rule.

Differential Revision: https://reviews.llvm.org/D33517

llvm-svn: 306011
2017-06-22 15:46:54 +00:00
Sanjay Patel e800df8eac [InstCombine] add peekThroughBitcast() helper; NFC
This is an NFC portion of D33517. We have similar helpers in the backend.

llvm-svn: 306008
2017-06-22 15:28:01 +00:00
Craig Topper a074c101e5 [InstCombine] Cleanup using commutable matchers. Make a couple helper methods standalone static functions. Put 'if' around variable declaration instead of after. NFC
llvm-svn: 305941
2017-06-21 18:57:00 +00:00
Craig Topper 5b173f2bb3 [InstCombine] Add range metadata to cttz/ctlz/ctpop intrinsic calls based on known bits
Summary:
I noticed that passing known bits across these intrinsics isn't great at capturing the information we really know. Turning known bits of the input into known bits of a count output isn't able to convey a lot of what we really know.

This patch adds range metadata to these intrinsics based on the known bits.

Currently the patch punts if we already have range metadata present.

Reviewers: spatel, RKSimon, davide, majnemer

Reviewed By: RKSimon

Subscribers: sanjoy, hfinkel, llvm-commits

Differential Revision: https://reviews.llvm.org/D32582

llvm-svn: 305927
2017-06-21 16:32:35 +00:00
Craig Topper ae86cc725d [InstCombine] Don't let folding (select (icmp eq (and X, C1), 0), Y, (or Y, C2)) create more instructions than it removes
Summary:
Previously this folding had no checks to see if it was going to result in less instructions. This was pointed out during the review of D34184

This patch adds code to count how many instructions its going to create vs how many its going to remove so we can make a proper decision.

Reviewers: spatel, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34437

llvm-svn: 305926
2017-06-21 16:07:13 +00:00
Sanjay Patel 4ccbd58d70 [InstCombine] fix code/test comments for r305792; NFC
These diffs were in the last version of the patch in D33342,
but I accidentally committed the previous rev. 

llvm-svn: 305793
2017-06-20 12:45:46 +00:00
Sanjay Patel adca825dc1 [InstCombine] try to canonicalize xor-of-icmps to and-of-icmps
We have a large portfolio of folds for and-of-icmps and or-of-icmps in InstSimplify and InstCombine, 
but hardly anything for xor-of-icmps. Rather than trying to rethink and translate all of those folds, 
we can use the truth table definition of xor:

X ^ Y --> (X | Y) & !(X & Y)

...to see if we can convert the xor to and/or and then use the existing folds.

http://rise4fun.com/Alive/J9v

Differential Revision: https://reviews.llvm.org/D33342

llvm-svn: 305792
2017-06-20 12:40:55 +00:00
Bjorn Pettersson 475fcd9cd8 [InstCombine] Make sure AddReachableCodeToWorklist sets MadeIRChange
Summary:
Some optimizations in AddReachableCodeToWorklist did not update
the MadeIRChange state. This could happen both when removing
trivially dead instructions (DCE) and at constant folds.

It is essential that changes to the IR is reported correctly,
since for example InstCombinePass::run() will indicate that all
analyses are preserved otherwise.
And the CGPassManager determines if the CallGraph is up-to-date
based on status from InstructionCombiningPass::runOnFunction().

The new test case early_dce_clobbers_callgraph.ll is a reproducer
for some asserts that started to trigger after changes in the
inliner in r305245. With this patch the test case passes again.

Reviewers: sanjoy, craig.topper, dblaikie

Reviewed By: craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34346

llvm-svn: 305725
2017-06-19 18:00:27 +00:00
Craig Topper a7529b68cc [InstCombine] Cleanup some duplicated one use checks
Summary:
These 4 patterns have the same one use check repeated twice for each. Once without a cast and one with. But the cast has no effect on what method is called.

For the OR case I believe it is always profitable regardless of the number of uses since we'll never increase the instruction count.

For the AND case I believe it is profitable if the pair of xors has one use such that we'll get rid of it completely. Or if the C value is something freely invertible, in which case the not doesn't cost anything.

Reviewers: spatel, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34308

llvm-svn: 305705
2017-06-19 16:23:49 +00:00
Anna Thomas 6bc14c65ad [InstCombine] Set correct insertion point for selects generated while folding phis
Summary:
When we fold vector constants that are operands of phi's that feed into select,
we need to set the correct insertion point for the *new* selects that get generated.
The correct insertion point is the incoming block for the phi.
Such cases can occur with patch r298845, which fixed folding of
vector constants, but the new selects could be inserted incorrectly (as the added
test case shows).

Reviewers: majnemer, spatel, sanjoy

Reviewed by: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34162

llvm-svn: 305591
2017-06-16 21:08:37 +00:00
Daniel Neilson 3faabbbe85 [Atomics] Rename and change prototype for atomic memcpy intrinsic
Summary:

Background: http://lists.llvm.org/pipermail/llvm-dev/2017-May/112779.html

This change is to alter the prototype for the atomic memcpy intrinsic. The prototype itself is being changed to more closely resemble the semantics and parameters of the llvm.memcpy intrinsic -- to ease later combination of the llvm.memcpy and atomic memcpy intrinsics. Furthermore, the name of the atomic memcpy intrinsic is being changed to make it clear that it is not a generic atomic memcpy, but specifically a memcpy is unordered atomic.

Reviewers: reames, sanjoy, efriedma

Reviewed By: reames

Subscribers: mzolotukhin, anna, llvm-commits, skatkov

Differential Revision: https://reviews.llvm.org/D33240

llvm-svn: 305558
2017-06-16 14:43:59 +00:00
Craig Topper da6ea0d3e8 [InstCombine] Fold (!iszero(A & K1) & !iszero(A & K2)) -> (A & (K1 | K2)) == (K1 | K2) if K1 and K2 are a 1-bit mask
Summary: This is the demorganed version of the case we already handle for the OR of iszero.

Reviewers: spatel

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34244

llvm-svn: 305548
2017-06-16 05:10:37 +00:00
Craig Topper 2ba991ff2c [InstCombine] Add two FIXMEs for bad single use checks. NFC
llvm-svn: 305510
2017-06-15 21:38:48 +00:00
Craig Topper f2d3e6d3d5 [InstCombine] Make the context instruction parameter of foldOrOfICmps a reference to discourage passing nullptr and to remove the '&' from all of the call sites. NFC
llvm-svn: 305493
2017-06-15 19:09:51 +00:00
Craig Topper 6eec9e21a5 [InstCombine] Handle (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2) when the one of the Ands is commuted relative to the other
Currently we expect A to be on the same side in both Ands but nothing guarantees that.

While there also switch to using matchers for some of the code.

Differential Revision: https://reviews.llvm.org/D34230

llvm-svn: 305487
2017-06-15 17:55:20 +00:00
Sanjay Patel 2e33bbaff0 [InstCombine] lshr (sext iM X to iN), N-M --> zext (ashr X, min(N-M, M-1)) to iN
This is a follow-up to https://reviews.llvm.org/D33879 / https://reviews.llvm.org/rL304939 ,
and was discussed in https://reviews.llvm.org/D33338.

We prefer this form because a narrower shift may be cheaper, and we can more easily fold a
zext than a sext.

http://rise4fun.com/Alive/slVe

Name: shz
%s = sext i8 %x to i12
%r = lshr i12 %s, 4
=>
%a = ashr i8 %x, 4
%r = zext i8 %a to i12 

llvm-svn: 305190
2017-06-12 14:23:43 +00:00
Andrew Kaylor 647025f9e1 [InstSimplify] Don't constant fold or DCE calls that are marked nobuiltin
Differential Revision: https://reviews.llvm.org/D33737

llvm-svn: 305132
2017-06-09 23:18:11 +00:00
Craig Topper a420562257 [InstCombine] Pass a proper context instruction to all of the calls into InstSimplify
Summary: This matches the behavior we already had for compares and makes us consistent everywhere.

Reviewers: dberlin, hfinkel, spatel

Reviewed By: dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33604

llvm-svn: 305049
2017-06-09 03:21:29 +00:00
Sanjay Patel 66f7fdb300 [InstCombine] fold lshr (sext X), C1 --> zext (lshr X, C2)
This was discussed in D33338. We have larger pattern-matching ending in a truncate that 
we can reduce or remove by handling these smaller patterns first. Further motivation is 
that narrower shift ops are easier for value tracking and zext is better than sext.

http://rise4fun.com/Alive/rhh

Name: boolshift
%sext = sext i1 %x to i8
%r = lshr i8 %sext, 7

=>

%r = zext i1 %x to i8

Name: noboolshift
%sext = sext i3 %x to i8
%r = lshr i8 %sext, 7

=>

%sh = lshr i3 %x, 2
%r = zext i3 %sh to i8

Differential Revision: https://reviews.llvm.org/D33879

llvm-svn: 304939
2017-06-07 20:32:08 +00:00
Craig Topper 73ba1c84be [InstCombine][InstSimplify] Use APInt::isNullValue/isOneValue to reduce compiled code for comparing APInts with 0 and 1. NFC
These methods are specifically optimized to only counting leading zeros without an additional uint64_t compare.

llvm-svn: 304876
2017-06-07 07:40:37 +00:00
Craig Topper 29c282eac8 [InstCombine] Fix two asserts that were accidentally checking that an APInt pointer is non-zero instead of checking that the APInt self is non-zero.
I believe this code used to use APInt references which would have worked. But then they were changed to pointers to allow m_APInt to be used.

llvm-svn: 304875
2017-06-07 07:40:29 +00:00
Zachary Turner 264b5d9e88 Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864
2017-06-07 03:48:56 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Sven van Haastregt 78819e0fd4 [InstCombine] Fix extractelement use before def
This fixes a bug that can cause extractelements with operands that
haven't been defined yet to be inserted at a wrong point when
optimising insertelements.

Patch by Karl Hylen.

Differential Revision: https://reviews.llvm.org/D33449

llvm-svn: 304701
2017-06-05 09:18:10 +00:00
Craig Topper 0799ff9e64 [InstCombine] Add support for simplifying ctlz/cttz intrinsics based on known bits.
llvm-svn: 304669
2017-06-03 18:50:32 +00:00
Sanjay Patel ce241f48c5 [InstCombine] fix icmp with not op and constant to work with splat vector constant
llvm-svn: 304562
2017-06-02 16:29:41 +00:00
Sanjay Patel 4dc85eb75a [InstCombine] improve perf by not creating a known non-canonical instruction
Op1 (RHS) is a constant, so putting it on the LHS makes us churn through visitICmp
an extra time to canonicalize it:

INSTCOMBINE ITERATION #1 on cmpnot
IC: ADDING: 3 instrs to worklist
IC: Visiting:   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp sgt i8 %notx, 42
IC: Old =   %cmp = icmp sgt i8 %notx, 42
    New =   <badref> = icmp sgt i8 -43, %x
IC: ADD:   %cmp = icmp sgt i8 -43, %x
IC: ERASE   %1 = icmp sgt i8 %notx, 42
IC: ADD:   %notx = xor i8 %x, -1
IC: DCE:   %notx = xor i8 %x, -1
IC: ERASE   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp sgt i8 -43, %x
IC: Mod =   %cmp = icmp sgt i8 -43, %x
    New =   %cmp = icmp slt i8 %x, -43
IC: ADD:   %cmp = icmp slt i8 %x, -43
IC: Visiting:   %cmp = icmp slt i8 %x, -43
IC: Visiting:   ret i1 %cmp

If we create the swapped ICmp directly, we go faster:

INSTCOMBINE ITERATION #1 on cmpnot
IC: ADDING: 3 instrs to worklist
IC: Visiting:   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp sgt i8 %notx, 42
IC: Old =   %cmp = icmp sgt i8 %notx, 42
    New =   <badref> = icmp slt i8 %x, -43
IC: ADD:   %cmp = icmp slt i8 %x, -43
IC: ERASE   %1 = icmp sgt i8 %notx, 42
IC: ADD:   %notx = xor i8 %x, -1
IC: DCE:   %notx = xor i8 %x, -1
IC: ERASE   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp slt i8 %x, -43
IC: Visiting:   ret i1 %cmp

llvm-svn: 304558
2017-06-02 16:11:14 +00:00
Reid Kleckner 5fbdd17714 [IR] Add additional addParamAttr/removeParamAttr to AttributeList API
Summary:
Fairly straightforward patch to fill in some of the holes in the
attributes API with respect to accessing parameter/argument attributes.
The patch aims to step further towards encapsulating the
idx+FirstArgIndex pattern to access these attributes to within the
AttributeList.

Patch by Daniel Neilson!

Reviewers: rnk, chandlerc, pete, javed.absar, reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33355

llvm-svn: 304329
2017-05-31 19:23:09 +00:00
Craig Topper d45185f231 [InstCombine] Pass the DominatorTree, AssumptionCache, and context instruction to a few calls to isKnownPositive, isKnownNegative, and isKnownNonZero
Every other place in InstCombine that uses these methods in ValueTracking already pass this information. This makes the remaining sites consistent.

Differential Revision: https://reviews.llvm.org/D33567

llvm-svn: 304018
2017-05-26 18:23:57 +00:00
Craig Topper d4039f7283 [InstCombine] Add an InstCombine specific wrapper around isKnownToBeAPowerOfTwo to shorten code. NFC
We have wrappers for several other ValueTracking methods that take care of passing all of the analysis and assumption cache parameters. This extends it to isKnownToBeAPowerOfTwo.

llvm-svn: 303924
2017-05-25 21:51:12 +00:00
Artur Pilipenko 315eafc339 [InstCombine] Teach isAllocSiteRemovable to look through addrspacecasts
Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D28565

llvm-svn: 303870
2017-05-25 15:14:48 +00:00
Sanjay Patel 5150612012 [InstCombine] make icmp-mul fold more efficient
There's probably a lot more like this (see also comments in D33338 about responsibility), 
but I suspect we don't usually get a visible manifestation.

Given the recent interest in improving InstCombine efficiency, another potential micro-opt
that could be repeated several times in this function: morph the existing icmp pred/operands
instead of creating a new instruction.

llvm-svn: 303860
2017-05-25 14:13:57 +00:00
Sanjay Patel 07b1ba54b5 [InstCombine] use m_APInt to allow icmp-mul-mul vector fold
The swapped operands in the first test is a manifestation of an 
inefficiency for vectors that doesn't exist for scalars because 
the IRBuilder checks for an all-ones mask for scalars, but not 
vectors.

llvm-svn: 303818
2017-05-24 22:58:17 +00:00
Craig Topper 2f9c6dafe3 [InstCombine] Merge together the SimplifyDemandedUseBits implementations for ZExt and Trunc. NFC
While there avoid resizing the DemandedMask twice. Make a copy into a separate variable instead. This potentially removes an allocation on large bit widths.

With the use of the zextOrTrunc methods on APInt and KnownBits these can be made almost source identical. The only difference is the zero of the upper bits for ZExt. This is similar to how its done in computeKnownBits in ValueTracking.

llvm-svn: 303791
2017-05-24 18:40:25 +00:00
Craig Topper 1c660dbea6 [InstCombine] Use less bitwise operations to handle Instruction::SExt in SimplifyDemandedUseBits. Other improvements.
The current code created a NewBits mask and used it as a mask several times. One of them just before a call to trunc making it unnecessary. A call to getActiveBits can get us the same information for the case. We also ORed with this mask later when we should have just sign extended the known bits.

We also called trunc on the guaranteed to be zero KnownZeros/Ones masks entering this code. Creating appropriately sized temporary APInts is probably better.

Differential Revision: https://reviews.llvm.org/D32098

llvm-svn: 303779
2017-05-24 17:33:30 +00:00
Craig Topper 8205a1a9b6 [ValueTracking] Convert most of the calls to computeKnownBits to use the version that returns the KnownBits object.
This continues the changes started when computeSignBit was replaced with this new version of computeKnowBits.

Differential Revision: https://reviews.llvm.org/D33431

llvm-svn: 303773
2017-05-24 16:53:07 +00:00
Sanjay Patel d3106add77 [InstCombine] allow icmp-xor folds for vectors (PR33138)
This fixes the first part of:
https://bugs.llvm.org/show_bug.cgi?id=33138

More work is needed for the bitcasted variant.

llvm-svn: 303660
2017-05-23 17:29:58 +00:00
Craig Topper 7e0aeeb884 [KnownBits] Use !hasConflict() in asserts in place of Zero & One == 0 or similar. NFC
llvm-svn: 303614
2017-05-23 07:18:37 +00:00
Craig Topper 2b1fc32f22 [InstCombine] Cleanup the interface for overflow checks
Summary:
Fix naming conventions and const correctness.
This completes the changes made in rL303029.

Patch by Yoav Ben-Shalom.

Reviewers: craig.topper

Reviewed By: craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33377

llvm-svn: 303529
2017-05-22 06:25:31 +00:00
Craig Topper aaef41f71b [KnownBits] Use isNegative/isNonNegative to shorten some code. NFC
llvm-svn: 303522
2017-05-22 00:49:33 +00:00
Davide Italiano 21a49dcdf1 [InstCombine] Take in account the size in sext->lshr->trunc patterns.
Otherwise we end up miscompiling, transforming:

define i8 @tinky() {
  %sext = sext i1 1 to i16
  %hibit = lshr i16 %sext, 15
  %tr = trunc i16 %hibit to i8
  ret i8 %tr
}

into:

  %sext = sext i1 1 to i8
  ret i8 %sext

and the first get folded to ret i8 1, while the second gets folded
to ret i8 -1.

Eventually we should get rid of this transform entirely, but for now,
this at least fixes a know correctness bug.

Differential Revision:  https://reviews.llvm.org/D33338

llvm-svn: 303513
2017-05-21 20:30:27 +00:00
Sanjay Patel 5e456b943a [InstCombine] add helper to foldXorOfICmps(); NFCI
Also, fix the old-style capitalization of the related functions
and move them to the 'private' section of the class since they
are just helpers of the visit* functions.

As shown in the post-commit comments for D32143, we are missing
folds for xor-of-icmps. 

llvm-svn: 303381
2017-05-18 20:53:16 +00:00
Sanjay Patel ba212c241a [InstCombine] handle icmp i1 X, C early to avoid creating an unknown pattern
The missing optimization for xor-of-icmps still needs to be added, but by
being more efficient (not generating unnecessary logic ops with constants)
we avoid the bug.

See discussion in post-commit comments:
https://reviews.llvm.org/D32143

llvm-svn: 303312
2017-05-17 22:29:40 +00:00
Sanjay Patel e5747e3cbd [InstCombine] move icmp bool canonicalizations to helper; NFC
As noted in the post-commit comments in D32143, we should be
catching the constant operand cases sooner to be more efficient
and less likely to expose a missing fold.

llvm-svn: 303309
2017-05-17 22:15:07 +00:00
Sanjay Patel b2e7003103 [InstCombine] add isCanonicalPredicate() helper function and use it; NFCI
There should be a slight efficiency improvement from handling icmp/fcmp with one matcher and reducing duplicated code.

The larger motivation is that there are questions about how predicate canonicalization is handled, and the refactoring
should make it easier if we want to change any of that behavior.

1. As noted in the code comment, we've chosen 3 of the 16 FCMP preds as not canonical. Why those 3? It goes back to 
   rL32751 from what I can tell, but I'm not sure if there's a justification for that rule.
2. We currently do not canonicalize integer select conditions. Should we use the same rule that applies to branches 
   for selects?
3. We currently do canonicalize some FP select conditions, and those rules would conflict with the rule shown here. 
   Should one or both be changed? 

No-functional-change-intended, but adding tests anyway because there's no coverage for most of the predicates.

Differential Revision: https://reviews.llvm.org/D33247

llvm-svn: 303261
2017-05-17 14:21:19 +00:00
Dmitry Mikulin fce148c568 In debug builds non-trivial amount of time is spent in InstCombine processing
@llvm.dbg.* calls in visitCallInst(). They can be safely ignored.

llvm-svn: 303202
2017-05-16 20:08:49 +00:00
Sanjay Patel 878715f978 [InstCombine] restrict icmp fold with 2 sdiv exact operands (PR32949)
This is the InstCombine counterpart to D32954. 
I added some comments about the code duplication in:
rL302436

Alive-based verification:
http://rise4fun.com/Alive/dPw

This is a 2nd fix for the problem reported in:
https://bugs.llvm.org/show_bug.cgi?id=32949

Differential Revision: https://reviews.llvm.org/D32970

llvm-svn: 303105
2017-05-15 19:27:53 +00:00
Sanjay Patel 941e8dfcbf [InstCombine] use m_OneUse to reduce code; NFCI
llvm-svn: 303090
2017-05-15 18:08:17 +00:00
Craig Topper 1a36b7d836 [ValueTracking] Replace all uses of ComputeSignBit with computeKnownBits.
This patch finishes off the conversion of ComputeSignBit to computeKnownBits.

Differential Revision: https://reviews.llvm.org/D33166

llvm-svn: 303035
2017-05-15 06:39:41 +00:00
Craig Topper bb9737247a [InstCombine] Merge duplicate functionality between InstCombine and ValueTracking
Summary:
Merge overflow computation for signed add,
appearing both in InstCombine and ValueTracking.

As part of the merge,
cleanup the interface for overflow checks in InstCombine.

Patch by Yoav Ben-Shalom.

Reviewers: craig.topper, majnemer

Reviewed By: craig.topper

Subscribers: takuto.ikuta, llvm-commits

Differential Revision: https://reviews.llvm.org/D32946

llvm-svn: 303029
2017-05-15 02:44:08 +00:00
Craig Topper 26c4159956 [InstCombine] Remove 'return' of a called function that also returned void. NFC
llvm-svn: 303028
2017-05-15 02:30:27 +00:00
Craig Topper 935f7b050f [InstCombine] Prevent InstCombine from triggering an extra iteration if something changed in the initial Worklist creation
Summary:
If the Worklist build causes an IR change this change flag currently factors into the flag for running another iteration of the iteration loop. But only changes during processing should trigger another loop.

This patch captures the worklist creation change flag into the outside the loop flag currently used for DbgDeclares and only sends that flag up to the caller. Rerunning the loop only depends on IC.run() now.

This uses the debug output of InstCombine to determine if one or two iterations run. I couldn't think of a better way to detect it since the second spurious iteration shoudn't make any visible changes. Just wasted computation.

I can do a pre-commit of the test case with the CHECK-NOT as a CHECK if this is an ok way to check this.

This is a subset of D31678 as I'm still not sure how to verify the analysis behavior for that.

Reviewers: davide, majnemer, spatel, chandlerc

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32453

llvm-svn: 302982
2017-05-13 06:56:04 +00:00
Craig Topper 8df66c602a [KnownBits] Add bit counting methods to KnownBits struct and use them where possible
This patch adds min/max population count, leading/trailing zero/one bit counting methods.

The min methods return answers based on bits that are known without considering unknown bits. The max methods give answers taking into account the largest count that unknown bits could give.

Differential Revision: https://reviews.llvm.org/D32931

llvm-svn: 302925
2017-05-12 17:20:30 +00:00
Sanjay Patel 40a87a909b [InstCombine] remove fold that swaps xor/or with constants; NFCI
// (X ^ C1) | C2 --> (X | C2) ^ (C1&~C2)

This canonicalization was added at:
https://reviews.llvm.org/rL7264 

By moving xors out/down, we can more easily combine constants. I'm adding
tests that do not change with this patch, so we can verify that those kinds
of transforms are still happening.

This is no-functional-change-intended because there's a later fold:
// (X^C)|Y -> (X|Y)^C iff Y&C == 0
...and demanded-bits appears to guarantee that any fold that would have
hit the fold we're removing here would be caught by that 2nd fold.

Similar reasoning was used in:
https://reviews.llvm.org/rL299384

The larger motivation for removing this code is that it could interfere with 
the fix for PR32706:
https://bugs.llvm.org/show_bug.cgi?id=32706

Ie, we're not checking if the 'xor' is actually a 'not', so we could reverse
a 'not' optimization and cause an infinite loop by altering an 'xor X, -1'. 

Differential Revision: https://reviews.llvm.org/D33050

llvm-svn: 302733
2017-05-10 21:33:55 +00:00
Sanjay Patel 2e069f250a [InstCombine] add (ashr (shl i32 X, 31), 31), 1 --> and (not X), 1
This is another step towards favoring 'not' ops over random 'xor' in IR:
https://bugs.llvm.org/show_bug.cgi?id=32706

This transformation may have occurred in longer IR sequences using computeKnownBits,
but that could be much more expensive to calculate.

As the scalar result shows, we do not currently favor 'not' in all cases. The 'not'
created by the transform is transformed again (unnecessarily). Vectors don't have
this problem because vectors are (wrongly) excluded from several other combines.

llvm-svn: 302659
2017-05-10 13:56:52 +00:00
Sanjay Patel 4133d4a56e [InstCombine] add helper function for add X, C folds; NFCI
llvm-svn: 302605
2017-05-10 00:07:16 +00:00
Sanjay Patel 7caaa79879 [InstCombine] clean up matchDeMorgansLaws(); NFCI
The motivation for getting rid of dyn_castNotVal is to allow fixing:
https://bugs.llvm.org/show_bug.cgi?id=32706

So this was supposed to be functional-change-intended for the case
of inverting constants and applying DeMorgan. However, I can't find 
any cases where that pattern will actually get to matchDeMorgansLaws()
because we have other folds in visitAnd/visitOr that do the same
thing. So this ends up just being a clean-up patch with slight efficiency
improvement, but no-functional-change-intended.

llvm-svn: 302581
2017-05-09 20:05:05 +00:00
Sanjay Patel 6844e21f59 [InstCombineCasts] Fix checks in sext->lshr->trunc pattern.
The comment says to avoid the case where zero bits are shifted into the truncated value, 
but the code checks that the shift is smaller than the truncated value instead of the 
number of bits added by the sign extension. Fixing this allows a shift by more than the 
value size to be introduced, which is undefined behavior, so the shift is capped at the 
value size minus one, which has the expected behavior of filling the value with the sign 
bit.

Patch by Jacob Young!

Differential Revision: https://reviews.llvm.org/D32285

llvm-svn: 302548
2017-05-09 16:24:59 +00:00
Sanjay Patel a1c8814891 [InstCombine] add folds for not-of-shift-right
This is another step towards getting rid of dyn_castNotVal, 
so we can recommit:
https://reviews.llvm.org/rL300977

As the tests show, we were missing the lshr case for constants
and both ashr/lshr vector splat folds. The ashr case with constant
was being performed inefficiently in 2 steps. It's also possible
there was a latent bug in that case because we can't do that fold
if the constant is positive:
http://rise4fun.com/Alive/Bge

llvm-svn: 302465
2017-05-08 20:49:59 +00:00
Sanjay Patel 2a06263036 [InstCombine] use local variable to reduce code duplication; NFCI
llvm-svn: 302438
2017-05-08 16:33:42 +00:00
Sanjay Patel 2df38a80f1 [InstCombine/InstSimplify] add comments about code duplication; NFC
llvm-svn: 302436
2017-05-08 16:21:55 +00:00
Sanjay Patel 599e65b1ff [InstSimplify] use ConstantRange to simplify or-of-icmps
We can simplify (or (icmp X, C1), (icmp X, C2)) to 'true' or one of the icmps in many cases.
I had to check some of these with Alive to prove to myself it's right, but everything seems 
to check out. Eg, the deleted code in instcombine was completely ignoring predicates with
mismatched signedness.

This is a follow-up to:
https://reviews.llvm.org/rL301260
https://reviews.llvm.org/D32143

llvm-svn: 302370
2017-05-07 15:11:40 +00:00
Craig Topper f0aeee01c3 [KnownBits] Add wrapper methods for setting and clear all bits in the underlying APInts in KnownBits.
This adds routines for reseting KnownBits to unknown, making the value all zeros or all ones. It also adds methods for querying if the value is zero, all ones or unknown.

Differential Revision: https://reviews.llvm.org/D32637

llvm-svn: 302262
2017-05-05 17:36:09 +00:00
Craig Topper cff357c322 [InstCombine][KnownBits] Use KnownBits better to detect nsw adds
Change checkRippleForAdd from a heuristic to a full check -
if it is provable that the add does not overflow return true, otherwise false.

Patch by Yoav Ben-Shalom

Differential Revision: https://reviews.llvm.org/D32686

llvm-svn: 302093
2017-05-03 23:22:46 +00:00
Craig Topper 8189a87a1e [KnownBits] Add methods for determining if KnownBits is a constant value
This patch adds isConstant and getConstant for determining if KnownBits represents a constant value and to retrieve the value. Use them to simplify code.

Differential Revision: https://reviews.llvm.org/D32785

llvm-svn: 302091
2017-05-03 23:12:29 +00:00
Craig Topper d938fd1397 [KnownBits] Add zext, sext, and trunc methods to KnownBits
This patch adds zext, sext, and trunc methods to KnownBits and uses them where possible.

Differential Revision: https://reviews.llvm.org/D32784

llvm-svn: 302088
2017-05-03 22:07:25 +00:00
Reid Kleckner a0b45f4bfc [IR] Abstract away ArgNo+1 attribute indexing as much as possible
Summary:
Do three things to help with that:
- Add AttributeList::FirstArgIndex, which is an enumerator currently set
  to 1. It allows us to change the indexing scheme with fewer changes.
- Add addParamAttr/removeParamAttr. This just shortens addAttribute call
  sites that would otherwise need to spell out FirstArgIndex.
- Remove some attribute-specific getters and setters from Function that
  take attribute list indices.  Most of these were only used from
  BuildLibCalls, and doesNotAlias was only used to test or set if the
  return value is malloc-like.

I'm happy to split the patch, but I think they are probably easier to
review when taken together.

This patch should be NFC, but it sets the stage to change the indexing
scheme to this, which is more convenient when indexing into an array:
  0: func attrs
  1: retattrs
  2...: arg attrs

Reviewers: chandlerc, pete, javed.absar

Subscribers: david2050, llvm-commits

Differential Revision: https://reviews.llvm.org/D32811

llvm-svn: 302060
2017-05-03 18:17:31 +00:00
Sanjay Patel 6381db18fe [InstCombine] don't use DeMorgan's Law on integer constants (2nd try)
This was originally checked in here:
https://reviews.llvm.org/rL301923

And reverted here:
https://reviews.llvm.org/rL301924

Because there's a clang test that would fail after this. I fixed/removed the
offending CHECK lines in:
https://reviews.llvm.org/rL301928

So let's try this again. Original commit message:

This is the fold that causes the infinite loop in BoringSSL
(https://github.com/google/boringssl/blob/master/crypto/cipher/e_rc2.c)
when we fix instcombine demanded bits to prefer 'not' ops as in https://reviews.llvm.org/D32255.

There are 2 or 3 problems with dyn_castNotVal, and I don't think we can
reinstate https://reviews.llvm.org/D32255 until dyn_castNotVal is completely eliminated.

1. As shown here, it transforms 'not' into random xor. This transform is harmful to SCEV and codegen because 'not' can often be folded while random xor cannot.
2. It does not transform vector constants. This is actually a good thing, but if you don't believe the above argument, then we shouldn't have excluded vectors.
3. It tries to avoid transforming not(not(X)). That's nice, but it doesn't match the greedy nature of instcombine. If we DeMorganize a pattern that has an extra 'not' in it: ~(~(~X) & Y) --> (~X | ~Y)

  That's just another case of DeMorgan, so we should trust that we'll fold that pattern too: (~X | ~ Y) --> ~(X & Y)

Differential Revision: https://reviews.llvm.org/D32665

llvm-svn: 301929
2017-05-02 15:31:40 +00:00
Sanjay Patel da0b4deafa revert r301923 : [InstCombine] don't use DeMorgan's Law on integer constants
There's a clang test that is wrongly using -O1 and failing after this commit.

llvm-svn: 301924
2017-05-02 14:48:23 +00:00
Sanjay Patel 096a981982 [InstCombine] don't use DeMorgan's Law on integer constants
This is the fold that causes the infinite loop in BoringSSL 
(https://github.com/google/boringssl/blob/master/crypto/cipher/e_rc2.c) 
when we fix instcombine demanded bits to prefer 'not' ops as in D32255.

There are 2 or 3 problems with dyn_castNotVal, and I don't think we can 
reinstate D32255 until dyn_castNotVal is completely eliminated.
1. As shown here, it transforms 'not' into random xor. This transform is 
   harmful to SCEV and codegen because 'not' can often be folded while 
   random xor cannot.
2. It does not transform vector constants. This is actually a good thing, 
   but if you don't believe the above argument, then we shouldn't have 
   excluded vectors.
3. It tries to avoid transforming not(not(X)). That's nice, but it doesn't
   match the greedy nature of instcombine. If we DeMorganize a pattern 
   that has an extra 'not' in it:
   ~(~(~X) & Y) --> (~X | ~Y)

   That's just another case of DeMorgan, so we should trust that we'll fold
   that pattern too:
   (~X | ~ Y) --> ~(X & Y)

Differential Revision: https://reviews.llvm.org/D32665

llvm-svn: 301923
2017-05-02 14:31:30 +00:00
Sanjay Patel 59d0aeaafe [InstCombine] check one-use before applying DeMorgan nor/nand folds
If we have ~(~X & Y), it only makes sense to transform it to (X | ~Y) when we do not need 
the intermediate (~X & Y) value. In that case, we would need an extra instruction to 
generate ~Y + 'or' (as shown in the test changes).

It's ok if we have multiple uses of ~X or Y, however. In those cases, we may not reduce the
instruction count or critical path, but we might improve throughput because we can generate 
~X and ~Y in parallel. Whether that actually makes perf sense or not for a target is something 
we can't answer in IR.

Differential Revision: https://reviews.llvm.org/D32703

llvm-svn: 301848
2017-05-01 22:25:42 +00:00
Sanjoy Das e6bca0eecb Rename WeakVH to WeakTrackingVH; NFC
This relands r301424.

llvm-svn: 301812
2017-05-01 17:07:49 +00:00
Craig Topper ca48af3c87 [KnownBits] Add methods for determining if the known bits represent a negative/nonnegative number and add methods for changing the negative/nonnegative state
Summary: This patch adds isNegative, isNonNegative for querying whether the sign bit is known. It also adds makeNegative and makeNonNegative for controlling the sign bit.

Reviewers: RKSimon, spatel, davide

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32651

llvm-svn: 301747
2017-04-29 16:43:11 +00:00
Craig Topper 24db6b800f [APInt] Add clearSignBit method. Use it and setSignBit in a few places. NFCI
llvm-svn: 301656
2017-04-28 16:58:05 +00:00
Craig Topper 24e71017aa [APInt] Use inplace shift methods where possible. NFCI
llvm-svn: 301612
2017-04-28 03:36:24 +00:00
Sanjay Patel 73d8c43da8 [InstCombine] fix matcher to bind to specific operand (PR32830)
Matching any random value would be very wrong:
https://bugs.llvm.org/show_bug.cgi?id=32830

llvm-svn: 301594
2017-04-27 21:55:03 +00:00
Craig Topper 9474e9b6c8 [InstCombine] Use APInt bit counting methods to avoid a temporary APInt. NFC
llvm-svn: 301516
2017-04-27 04:51:25 +00:00
Daniel Berlin 2c75c63063 InstCombine: Use the new SimplifyQuery versions of Simplify*. Use AssumptionCache, DominatorTree, TargetLibraryInfo everywhere.
llvm-svn: 301464
2017-04-26 20:56:07 +00:00
Craig Topper b45eabcf82 [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for computeKnownBits
This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit.

Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch.

I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases.

Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with.

Differential Revision: https://reviews.llvm.org/D32376

llvm-svn: 301432
2017-04-26 16:39:58 +00:00
Sanjoy Das 2cbeb00f38 Reverts commit r301424, r301425 and r301426
Commits were:

"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"

The changes assumed pointers are 8 byte aligned on all architectures.

llvm-svn: 301429
2017-04-26 16:37:05 +00:00
Sanjoy Das 01de557738 Rename WeakVH to WeakTrackingVH; NFC
Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.

Reviewers: dblaikie, davide

Reviewed By: davide

Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle

Differential Revision: https://reviews.llvm.org/D32266

llvm-svn: 301424
2017-04-26 16:20:52 +00:00
Craig Topper 09a5878d33 [InstCombine] Remove redundant code from SimplifyUsingDistributiveLaws
The code I've removed here exists in ExpandBinOp in InstSimplify which we call into before SimplifyUsingDistributiveLaws. The code in InstSimplify looks to have been copied from here.

I verified this code doesn't fire on any lit tests. Not that that proves its definitely dead.

Differential Revision: https://reviews.llvm.org/D32472

llvm-svn: 301341
2017-04-25 17:54:12 +00:00
Craig Topper f3dbd17d0a [APInt] Use isSubsetOf, intersects, and bit counting methods to reduce temporary APInts
This patch uses various APInt methods to reduce temporary APInt creation.

This should be all of the unrelated cleanups that got buried in D32376(creating a KnownBits struct) as well as some pointed out by Simon during the review of that. Plus a few improvements to use counting instead of masking.

I've left out any places where we do something like (KnownZero & KnownOne) != 0 as I plan to add a helper method to KnownBits to ask that question and didn't want to thrash that code an additional time.

Differential Revision: https://reviews.llvm.org/D32495

llvm-svn: 301338
2017-04-25 17:46:30 +00:00
Craig Topper 7603dce6b2 [InstCombine] Remove superfluous curly braces around a single line if body. NFC
llvm-svn: 301326
2017-04-25 16:48:19 +00:00
Craig Topper ba01143193 [InstCombine] Add missing commute handling to (A | B) & (B ^ (~A)) -> (A & B)
The matching here wasn't able to handle all the possible commutes. It always assumed the not would be on the left of the xor, but that's not guaranteed.

Differential Revision: https://reviews.llvm.org/D32474

llvm-svn: 301316
2017-04-25 15:19:04 +00:00
Craig Topper c4b48a32f0 [InstCombine] Use commutable matchers to reduce some code. NFC
llvm-svn: 301294
2017-04-25 06:02:11 +00:00
Sanjay Patel 35c362ebbb [InstSimplify] use ConstantRange to simplify more and-of-icmps
We can simplify (and (icmp X, C1), (icmp X, C2)) to one of the icmps in many cases. 
I had to check some of these with Alive to prove to myself it's right, but everything 
seems to check out. Eg, the code in instcombine was completely ignoring predicates with 
mismatched signedness.

Handling or-of-icmps would be a follow-up step.

Differential Revision: https://reviews.llvm.org/D32143

llvm-svn: 301260
2017-04-24 21:52:39 +00:00
Sanjay Patel 0889225f51 [InstSimplify] move (A & ~B) | (A ^ B) -> (A ^ B) from InstCombine
This is a straight cut and paste, but there's a bigger problem: if this
fold exists for simplifyOr, there should be a DeMorganized version for
simplifyAnd. But more than that, we have a patchwork of ad hoc logic
optimizations in InstCombine. There should be some structure to ensure 
that we're not missing sibling folds across and/or/xor.
 

llvm-svn: 301213
2017-04-24 18:24:36 +00:00
Matt Arsenault 02907f3039 InstCombine: Fix assert when reassociating fsub with undef
There is logic to track the expected number of instructions
produced. It thought in this case an instruction would
be necessary to negate the result, but here it folded
into a ConstantExpr fneg when the non-undef value operand
was cancelled out by the second fsub.

I'm not sure why we don't fold constant FP ops with undef currently,
but I think that would also avoid this problem.

llvm-svn: 301199
2017-04-24 17:24:37 +00:00
Nicolai Haehnle 9c66185315 InstCombine/AMDGPU: Fix constant folding of llvm.amdgcn.{icmp,fcmp}
Summary:
The return value of these intrinsics should always have 0 bits for
inactive threads. This means that when all arguments are constant
and the comparison evaluates to true, the intrinsic should return
the current exec mask.

Fixes some GL_ARB_shader_ballot tests.

Reviewers: arsenm

Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, llvm-commits, t-tye

Differential Revision: https://reviews.llvm.org/D32344

llvm-svn: 301195
2017-04-24 17:08:43 +00:00
Sanjay Patel e0c26e0640 [InstCombine] add/move folds for [not]-xor
We handled all of the commuted variants for plain xor already,
although they were scattered around and sometimes folded less
efficiently using distributive laws. We had no folds for not-xor.

Handling all of these patterns consistently is part of trying to 
reinstate:
https://reviews.llvm.org/rL300977

llvm-svn: 301144
2017-04-23 22:00:02 +00:00
Sanjay Patel d13b0bfdac [InstCombine] add pattern matches for commuted variants of xor-to-xor
There's probably some better way to write this that eliminates the
code duplication without hurting readability, but at least this
eliminates the logic holes and is hopefully slightly more efficient
than creating new instructions.

llvm-svn: 301129
2017-04-23 16:03:00 +00:00
Renato Golin 4abfb3d741 Revert "[APInt] Fix a few places that use APInt::getRawData to operate within the normal API."
This reverts commit r301105, 4, 3 and 1, as a follow up of the previous
revert, which broke even more bots.

For reference:
Revert "[APInt] Use operator<<= where possible. NFC"
Revert "[APInt] Use operator<<= instead of shl where possible. NFC"
Revert "[APInt] Use ashInPlace where possible."

PR32754.

llvm-svn: 301111
2017-04-23 12:15:30 +00:00
Craig Topper 5f68af0806 [APInt] Use operator<<= instead of shl where possible. NFC
llvm-svn: 301103
2017-04-23 05:18:31 +00:00
Sanjay Patel 3b863f8a1e [InstCombine] use 'match' to reduce code; NFCI
The later uses of dyn_castNotVal in this block are either
incomplete (doesn't handle vector constants) or overstepping
(shouldn't handle constants at all), but this first use is
just unnecessary. 'I' is obviously not a constant, and it 
can't be a not-of-a-not because that would already be
instsimplified.

llvm-svn: 301088
2017-04-22 18:05:35 +00:00
Artur Pilipenko 0632bdc648 Fix for PR32740 - Invalid floating type, unreachable between r300969 and r301029
The bug was introduced by r301018 "[InstCombine] fadd double (sitofp x), y check that the promotion is valid". The patch didn't expect that fadd can be on vectors not necessarily scalars. Add vector support along with the test.

llvm-svn: 301070
2017-04-22 07:24:52 +00:00
Sanjay Patel 8ce1d4cbe1 [InstCombine] revert r300977 and r301021
This can cause an inf-loop. Investigating...

llvm-svn: 301035
2017-04-21 20:29:17 +00:00
Sanjay Patel 0f001a4701 [InstCombine] use isSubsetOf() for efficiency
C | ~D == -1
~(C | ~D) == 0
~C & D == 0
D & ~C == 0
D.isSubsetOf(C)

llvm-svn: 301021
2017-04-21 19:16:52 +00:00
Artur Pilipenko 134d94f9a3 [InstCombine] fadd double (sitofp x), y check that the promotion is valid
Doing these transformations check that the result of integer addition is representable in the FP type.

(fadd double (sitofp x), fpcst) --> (sitofp (add int x, intcst))
(fadd double (sitofp x), (sitofp y)) --> (sitofp (add int x, y))

This is a fix for https://bugs.llvm.org//show_bug.cgi?id=27036

Reviewed By: andrew.w.kaylor, scanon, spatel

Differential Revision: https://reviews.llvm.org/D31182

llvm-svn: 301018
2017-04-21 18:45:25 +00:00
Sanjay Patel 347b54b093 [InstCombine] prefer xor with -1 because 'not' is easier to understand (PR32706)
This matches the demanded bits behavior in the DAG and should fix:
https://bugs.llvm.org/show_bug.cgi?id=32706

Differential Revision: https://reviews.llvm.org/D32255

llvm-svn: 300977
2017-04-21 14:03:54 +00:00
Craig Topper 358cd9ae3a [InstCombine] Remove the zextOrTrunc from ShrinkDemandedConstant.
The demanded mask and the constant should always be the same width for all callers today.

Also stop copying the demanded mask as its passed in. We should avoid allocating memory unless we are going to do something. The final AND to create the new constant will take care of it.

llvm-svn: 300927
2017-04-20 23:58:27 +00:00
Sanjay Patel cc663b82fa [InstCombine] function names start with lower-case letter; NFC
Forgot to make this fix with the signature change in r300911.

llvm-svn: 300912
2017-04-20 22:37:01 +00:00
Sanjay Patel c9485ca895 [InstCombine] allow shl+shr demanded bits folds with splat constants
llvm-svn: 300911
2017-04-20 22:33:54 +00:00
Sanjay Patel 3e1ae72fcf [InstCombine] allow shl demanded bits folds with splat constants
More fixes are needed to enable the helper SimplifyShrShlDemandedBits().

llvm-svn: 300898
2017-04-20 21:33:02 +00:00
Craig Topper ff23889609 [InstCombine] Use APInt::intersects and APInt::isSubsetOf to improve a few more places in SimplifyDemandedBits.
llvm-svn: 300896
2017-04-20 21:24:37 +00:00
Sanjay Patel fb5b3e773a [InstCombine] allow ashr/lshr demanded bits folds with splat constants
llvm-svn: 300888
2017-04-20 20:59:02 +00:00
Craig Topper 17f37ba3b9 [InstCombine] Use APInt::isSubsetOf to simplify some code in SimplifyDemandedBits. NFC
This allows us to use less temporary APInt for And and Invert operations.

llvm-svn: 300885
2017-04-20 20:47:35 +00:00
Craig Topper 0ec3f2f39a [InstCombine] Remove redundant code from SimplifyDemandedBits handling for Or. The code above it is equivalent if you work through the bitwise math.
llvm-svn: 300876
2017-04-20 19:31:22 +00:00
Craig Topper bcfd2d1789 [APInt] Rename getSignBit to getSignMask
getSignBit is a static function that creates an APInt with only the sign bit set. getSignMask seems like a better name to convey its functionality. In fact several places use it and then store in an APInt named SignMask.

Differential Revision: https://reviews.llvm.org/D32108

llvm-svn: 300856
2017-04-20 16:56:25 +00:00
Craig Topper a8129a1122 [APInt] Add isSubsetOf method that can check if one APInt is a subset of another without creating temporary APInts
This question comes up in many places in SimplifyDemandedBits. This makes it easy to ask without allocating additional temporary APInts.

The BitVector class provides a similar functionality through its (IMHO badly named) test(const BitVector&) method. Though its output polarity is reversed.

I've provided one example use case in this patch. I plan to do more as a follow up.

Differential Revision: https://reviews.llvm.org/D32258

llvm-svn: 300851
2017-04-20 16:17:13 +00:00
Craig Topper 83dc1c60aa In SimplifyDemandedUseBits, use computeKnownBits directly to handle Constants
Currently we don't explicitly process ConstantDataSequential, ConstantAggregateZero, or ConstantVector, or Undef before applying the Depth limit. Instead they occur after the depth check in the non-instruction path.

For the constant types that we do handle, the code is replicated from computeKnownBits.

This patch fixes the missing constant handling and the reduces the amount of code by just using computeKnownBits directly for any type of Constant.

Differential Revision: https://reviews.llvm.org/D32123

llvm-svn: 300849
2017-04-20 16:14:58 +00:00
Reid Kleckner aa0cec7d6d Simplify test for sret attribute in instcombine
This change is correct because the verifier requires that at most one
argument be marked 'sret'.

NFC, removes a use of AttributeList slot APIs.

llvm-svn: 300784
2017-04-19 23:17:47 +00:00
Craig Topper 9b71a402c2 [APInt] Cast calls to add/sub/mul overflow methods to void if only their overflow bool out param is used.
This is preparation for a clang change to improve the [[nodiscard]] warning to not be ignored on methods that return a class marked [[nodiscard]] that are defined in the class itself. See D32207.

We should consider adding wrapper methods to APInt that return the overflow flag directly and discard the APInt result. This would eliminate the void casts and the need to create a bool before the call to pass to the out param.

llvm-svn: 300758
2017-04-19 21:09:45 +00:00
Davide Italiano ffcb4df204 [InstCombine] Reduce visitLoadInst() code duplication. NFCI.
llvm-svn: 300717
2017-04-19 17:26:57 +00:00
Sanjoy Das f09c1e346e Add a getPointerOperandType() helper to LoadInst and StoreInst; NFC
I will use this in a later change.

llvm-svn: 300613
2017-04-18 22:00:54 +00:00
Craig Topper fc947bcfba [APInt] Use lshrInPlace to replace lshr where possible
This patch uses lshrInPlace to replace code where the object that lshr is called on is being overwritten with the result.

This adds an lshrInPlace(const APInt &) version as well.

Differential Revision: https://reviews.llvm.org/D32155

llvm-svn: 300566
2017-04-18 17:14:21 +00:00
Davide Italiano cdc937d0fc [InstCombine] Matchers work with both ConstExpr and Instructions.
So, `cast<Instruction>` is not guaranteed to succeed. Change the
code so that we create a new constant and use it in the newly
created instruction, as it's done in other places in InstCombine.

OK'ed by Sanjay/Craig. Fixes PR32686.

llvm-svn: 300495
2017-04-17 20:49:50 +00:00
Craig Topper d23004c37b Introduce APInt::isSignBitSet/isSignBitClear. Use in place isSignBitSet in place of isNegative in known bits tracking.
This makes statements like KnownZero.isNegative() (which means the value we're tracking is positive) less confusing.

llvm-svn: 300457
2017-04-17 16:38:20 +00:00
Matt Arsenault 7205f3c2e4 AMDGPU: SimplifyDemandedElts for image intrinsics
Causes some VGPR usage improvements in shaderdb, but
introduces some SGPR spilling regressions due to random
scheduling changes later.

llvm-svn: 300453
2017-04-17 15:12:44 +00:00
Craig Topper 218a359fbd [InstCombine] Simplify 1/X for vectors.
llvm-svn: 300439
2017-04-17 03:41:47 +00:00
Craig Topper 1a18a7c51e [InstCombine] Add support for vector srem->urem.
llvm-svn: 300437
2017-04-17 01:51:24 +00:00
Craig Topper f248468359 [InstCombine] Add support for turning vector sdiv into udiv.
llvm-svn: 300435
2017-04-17 01:51:19 +00:00
Craig Topper da886c665b [InstCombine][ValueTracking] When computing known bits for Srem make sure we don't compute known bits for the LHS twice.
If we already called computeKnownBits for the RHS being a constant power of 2, we've already computed everything we can and should just stop. I think previously we would still recurse if we had determined the result was negative or had not determined the sign bit at all.

llvm-svn: 300432
2017-04-16 21:46:12 +00:00
Craig Topper 0d304f01b4 [InstCombine] In SimplifyDemandedUseBits, don't bother to mask known bits of constants with DemandedMask.
Just because we didn't demand them doesn't mean they aren't known.

llvm-svn: 300430
2017-04-16 20:55:58 +00:00
Michael Zuckerman 16b20d2fc5 [X86][X86 intrinsics]Folding cmp(sub(a,b),0) into cmp(a,b) optimization
This patch adds new optimization (Folding cmp(sub(a,b),0) into cmp(a,b))
to instCombineCall pass and was written specific for X86 CMP intrinsics.

Differential Revision: https://reviews.llvm.org/D31398

llvm-svn: 300422
2017-04-16 13:26:08 +00:00
Sanjay Patel ef9f586bb2 [InstCombine] allow (X != C1 && X != C2) and similar patterns to match splat vector constants
llvm-svn: 300402
2017-04-15 17:55:06 +00:00
Craig Topper 9a458cd517 [InstCombine] MakeAnd/Or/Xor handling to reuse previous APInt computations
When checking if we should return a constant, we create some temporary APInts to see if we know all bits. But the exact computations we do are needed in several other locations in the same code.

This patch moves them to named temporaries so we can reuse them.

Ideally we'd write directly to KnownZero/One, but we currently seem to only write those variables after all the simplifications checks and I didn't want to change that with this patch.

Differential Revision: https://reviews.llvm.org/D32094

llvm-svn: 300376
2017-04-14 22:34:14 +00:00
Reid Kleckner fb502d2f5e [IR] Make paramHasAttr to use arg indices instead of attr indices
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.

Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.

llvm-svn: 300367
2017-04-14 20:19:02 +00:00
Sanjay Patel 7cfe41659c [InstCombine] (X != C1 && X != C2) --> (X | (C1 ^ C2)) != C2
...when C1 differs from C2 by one bit and C1 <u C2:
http://rise4fun.com/Alive/Vuo

And move related folds to a helper function. This reduces code duplication and
will make it easier to remove the scalar-only restriction as a follow-up step.

llvm-svn: 300364
2017-04-14 19:23:50 +00:00
Craig Topper fb71b7d3e0 [InstCombine] Support folding a subtract with a constant LHS into a phi node
We currently only support folding a subtract into a select but not a PHI. This fixes that.

I had to fix an assumption in FoldOpIntoPhi that assumed the PHI node was always in operand 0. Now we pass it in like we do for FoldOpIntoSelect. But we still require some dancing to find the Constant when we create the BinOp or ConstantExpr. This is based code is similar to what we do for selects.

Since I touched all call sites, this also renames FoldOpIntoPhi to foldOpIntoPhi to match coding standards.

Differential Revision: https://reviews.llvm.org/D31686

llvm-svn: 300363
2017-04-14 19:20:12 +00:00
Craig Topper c22c7b1459 [InstCombine] Refactor SimplifyUsingDistributiveLaws to more explicitly skip code when LHS/RHS aren't BinaryOperators
Currently this code always makes 2 or 3 calls to tryFactorization regardless of whether the LHS/RHS are BinaryOperators. We make 3 calls when both operands are BinaryOperators with the same opcode. Or surprisingly, when neither are BinaryOperators. This is because getBinOpsForFactorization returns Instruction::BinaryOpsEnd when the operand is not a BinaryOperator. If both LHS and RHS are not BinaryOperators then they both have an Opcode of Instruction::BinaryOpsEnd. When this happens we rely on tryFactorization to early out due to A/B/C/D being null. Similar behavior occurs for the other calls, we rely on getBinOpsForFactorization having made A/B or C/D null to get tryFactorization to early out.

We also rely on these null checks to check the result of getIdentityValue and early out for it.

This patches refactors this to pull these checks up to SimplifyUsingDistributiveLaws so we don't rely on BinaryOpsEnd as a sentinel or this A/B/C/D null behavior. I think this makes this code easier to reason about. Should also give a tiny performance improvement for cases where the LHS or RHS isn't a BinaryOperator.

Differential Revision: https://reviews.llvm.org/D31913

llvm-svn: 300353
2017-04-14 17:55:41 +00:00
Craig Topper c9a4fc0750 [InstCombine] Use APInt::setSignBit and APInt::isNegative(). NFC
llvm-svn: 300305
2017-04-14 05:09:04 +00:00
Reid Kleckner f021fab2af [IR] Make getParamAttributes take argument numbers, not ArgNo+1
Add hasParamAttribute() and use it instead of hasAttribute(ArgNo+1,
Kind) everywhere.

The fact that the AttributeList index for an argument is ArgNo+1 should
be a hidden implementation detail.

NFC

llvm-svn: 300272
2017-04-13 23:12:13 +00:00
Craig Topper e7563f8dda [InstCombine] Use APInt::getBitsSetFrom instead of inverting the result of getLowBitsSet. NFC
llvm-svn: 300265
2017-04-13 21:49:48 +00:00
Richard Smith 6c2615177b Revert accidentally-committed files in r300252.
llvm-svn: 300253
2017-04-13 20:31:21 +00:00
Richard Smith 55bd375b69 Remove all allocation and divisions from GreatestCommonDivisor
Switch from Euclid's algorithm to Stein's algorithm for computing GCD. This
avoids the (expensive) APInt division operation in favour of bit operations.
Remove all memory allocation from within the GCD loop by tweaking our `lshr`
implementation so it can operate in-place.

Differential Revision: https://reviews.llvm.org/D31968

llvm-svn: 300252
2017-04-13 20:29:59 +00:00
Reid Kleckner 257cb4e099 [InstCombine] Fix !prof metadata preservation for invokes
Summary:
Bug noticed by inspection.

Extend the test to handle invokes as well as calls, and rewrite it to
not depend on the inliner and other passes.

Also simplify the call site replacement code with CallSite, similar to
what I did to dead arg elimination and arg promotion (rL300235 and
rL300229).

Reviewers: danielcdh, davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32041

llvm-svn: 300251
2017-04-13 20:26:38 +00:00
Sanjay Patel 445d03bf00 [InstCombine] fold X == 0 || X == -1 to one compare (PR32524)
This is effectively a retry of:
https://reviews.llvm.org/rL299851
but now we have tests and an assert to make sure the bug
that was exposed with that attempt will not happen again.

I'll fix the code duplication and missing sibling fold next,
but I want to make this change as small as possible to reduce
risk since I messed it up last time.

This should fix:
https://bugs.llvm.org/show_bug.cgi?id=32524

llvm-svn: 300236
2017-04-13 18:47:06 +00:00
Reid Kleckner c3fae796fd [InstCombine] Simplify attribute code with new AttributeList::get NFC
llvm-svn: 300230
2017-04-13 18:11:03 +00:00
Sanjay Patel 9745d24a66 [InstCombine] use similar ops for related folds; NFCI
It's less efficient to produce 'ule' than 'ult' since we know we're going to
canonicalize to 'ult', but we shouldn't have duplicated code for these folds.

As a trade-off, this was a pretty terrible way to make a '2'. :)
       if (LHSC == SubOne(RHSC)) 
         AddC = ConstantExpr::getSub(AddOne(RHSC), LHSC);

The next steps are to share the code to fix PR32524 and add the missing 'and'
fold that was left out when PR14708 was fixed:
https://bugs.llvm.org/show_bug.cgi?id=14708

llvm-svn: 300222
2017-04-13 17:36:24 +00:00
Sanjay Patel a8ebb46e0e [InstCombine] fix assert to not always be true
llvm-svn: 300202
2017-04-13 16:05:01 +00:00
Reid Kleckner 7f72033e1c [IR] Take func, ret, and arg attrs separately in AttributeList::get
This seems like a much more natural API, based on Derek Schuff's
comments on r300015. It further hides the implementation detail of
AttributeList that function attributes come last and appear at index
~0U, which is easy for the user to screw up. git diff says it saves code
as well: 97 insertions(+), 137 deletions(-)

This also makes it easier to change the implementation, which I want to
do next.

llvm-svn: 300153
2017-04-13 00:58:09 +00:00
Craig Topper c75f94bfa5 [InstCombine] Teach SimplifyMultipleUseDemandedBits to handle And/Or/Xor known bits using the LHS/RHS known bits it already acquired without recursing back into computeKnownBits.
This replicates the known bits and constant creation code from the single use case for these instructions and adds it here. The computeKnownBits and constant creation code for other instructions is now in the default case of the opcode switch.

llvm-svn: 300094
2017-04-12 19:32:47 +00:00
Craig Topper cf3641fd57 [InstCombine] Remove unreachable code for turning an And where all demanded bits on both sides are known to be zero into a constant 0.
We already handled a superset check that included the known ones too and folded to a constant that may include ones. But it can also handle the case of no ones.

llvm-svn: 300093
2017-04-12 19:08:03 +00:00
Sanjay Patel 6e41018942 [InstCombine] fix wrong undef handling when converting select to shuffle
As discussed in:
https://bugs.llvm.org/show_bug.cgi?id=32486
...the canonicalization of vector select to shufflevector does not hold up
when undef elements are present in the condition vector. 

Try to make the undef handling clear in the code and the LangRef.

Differential Revision: https://reviews.llvm.org/D31980

llvm-svn: 300092
2017-04-12 18:39:53 +00:00
Craig Topper f35a7f7b49 [InstCombine] In SimplifyMultipleUseDemandedBits, use a switch instead of cascaded ifs on opcode. NFC
llvm-svn: 300085
2017-04-12 18:25:25 +00:00
Craig Topper 9a51c7f343 [InstCombine] Teach SimplifyDemandedInstructionBits that even if we reach an instruction that has multiple uses, if we know all the bits for the demanded bits for this context we can go ahead and create a constant.
Currently if we reach an instruction with multiples uses we know we can't do any optimizations to that instruction itself since we only have the demanded bits for one of the users. But if we know all of the bits are zero/one for that one user we can still go ahead and create a constant to give to that user.

This might then reduce the instruction to having a single use and allow additional optimizations on the other path.

This picks up an additional case that r300075 didn't catch.

Differential Revision: https://reviews.llvm.org/D31552

llvm-svn: 300084
2017-04-12 18:17:46 +00:00
Craig Topper b0076fe8b4 [InstCombine] Move portion of SimplifyDemandedUseBits that deals with instructions with multiple uses out to a separate method. NFCI
llvm-svn: 300082
2017-04-12 18:05:21 +00:00
Craig Topper 845033a6c9 Teach SimplifyDemandedUseBits that adding or subtractings 0s from every bit below the highest demanded bit can be simplified
If we are adding/subtractings 0s below the highest demanded bit we can just use the other operand and remove the operation.

My primary motivation is observing that we can call ShrinkDemandedConstant for the add/sub and create a 0 constant, rather than removing the add completely. In the case I saw, we modified the constant on an add instruction to a 0, but the add is not put into the worklist. So we didn't revisit it until the next InstCombine iteration. This caused an IR modification to remove add and a subsequent iteration to be ran.

With this change we get bypass the add in the first iteration and prevent the second iteration from changing anything.

Differential Revision: https://reviews.llvm.org/D31120

llvm-svn: 300075
2017-04-12 16:49:59 +00:00
Sanjay Patel 33439f982b [InstCombine] morph an existing instruction instead of creating a new one
One potential way to make InstCombine (very slightly?) faster is to recycle instructions 
when possible instead of creating new ones. It's not explicitly stated AFAIK, but we don't
consider this an "InstSimplify". We could, however, make a new layer to house transforms 
like this if that makes InstCombine more manageable (just throwing out an idea; not sure 
how much opportunity is actually here).

Differential Revision: https://reviews.llvm.org/D31863

llvm-svn: 300067
2017-04-12 15:11:33 +00:00
Chandler Carruth 927d8e610a [IR] Redesign the case iterator in SwitchInst to actually be an iterator
and to expose a handle to represent the actual case rather than having
the iterator return a reference to itself.

All of this allows the iterator to be used with common STL facilities,
standard algorithms, etc.

Doing this exposed some missing facilities in the iterator facade that
I've fixed and required some work to the actual iterator to fully
support the necessary API.

Differential Revision: https://reviews.llvm.org/D31548

llvm-svn: 300032
2017-04-12 07:27:28 +00:00
Craig Topper b5194eeebf [InstCombine][IR] Add a commutable BinOp matcher. Use it to reduce some code. NFC
llvm-svn: 300030
2017-04-12 05:49:28 +00:00
Reid Kleckner c2cb560045 [IR] Add AttributeSet to hide AttributeSetNode* again, NFC
Summary:
For now, it just wraps AttributeSetNode*. Eventually, it will hold
AvailableAttrs as an inline bitset, and adding and removing enum
attributes will be super cheap.

This sinks AttributeSetNode back down to lib/IR/AttributeImpl.h.

Reviewers: pete, chandlerc

Subscribers: llvm-commits, jfb

Differential Revision: https://reviews.llvm.org/D31940

llvm-svn: 300014
2017-04-12 00:38:00 +00:00
Craig Topper 957a94cc03 Fix spelling compliment->complement. Mostly refering to 2s complement. NFC
llvm-svn: 299970
2017-04-11 18:47:58 +00:00
Craig Topper 271b2245f4 [InstCombine] Use ConstantExpr::getBinOpIdentity to implement getIdentityValue.
This removes a TODO in getIdentityValue and may allow some transforms to occur earlier. But I was unable to find any transforms we didn't already handle.

llvm-svn: 299966
2017-04-11 17:42:40 +00:00
Sanjay Patel 28611acef9 revert r299851 - [InstCombine] fix matching of or-of-icmps constants (PR32524)
This is a candidate culprit for multiple bot fails, so reverting pending investigation.

llvm-svn: 299955
2017-04-11 15:57:32 +00:00
Craig Topper 8c75adf95b [InstCombine] Refinement of r299915. Only consider a ConstantVector for Neg if all the elements are Undef or ConstantInt.
llvm-svn: 299917
2017-04-11 06:32:48 +00:00
Craig Topper 18f9e424e7 [InstCombine] Support weird size element types in dyn_castNegVal.
llvm-svn: 299915
2017-04-11 05:42:47 +00:00
Reid Kleckner eb9dd5b87f Reland "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This re-lands r299875.

I introduced a bug in Clang code responsible for replacing K&R, no
prototype declarations with a real function definition with a prototype.
The bug was here:

       // Collect any return attributes from the call.
  -    if (oldAttrs.hasAttributes(llvm::AttributeList::ReturnIndex))
  -      newAttrs.push_back(llvm::AttributeList::get(newFn->getContext(),
  -                                                  oldAttrs.getRetAttributes()));
  +    newAttrs.push_back(oldAttrs.getRetAttributes());

Previously getRetAttributes() carried AttributeList::ReturnIndex in its
AttributeList. Now that we return the AttributeSetNode* directly, it no
longer carries that index, and we call this overload with a single node:
  AttributeList::get(LLVMContext&, ArrayRef<AttributeSetNode*>)

That aborted with an assertion on x86_32 targets. I added an explicit
triple to the test and added CHECKs to help find issues like this in the
future sooner.

llvm-svn: 299899
2017-04-10 23:31:05 +00:00
Reid Kleckner 211b1f324f Revert "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This reverts r299875. A Linux bot came back with a test failure:
http://bb.pgr.jp/builders/test-clang-i686-linux-RA/builds/741/steps/test_clang/logs/Clang%20%3A%3A%20CodeGen__2006-05-19-SingleEltReturn.c

llvm-svn: 299878
2017-04-10 20:34:19 +00:00
Reid Kleckner 324c99dee5 [IR] Make AttributeSetNode public, avoid temporary AttributeList copies
Summary:
AttributeList::get(Fn|Ret|Param)Attributes no longer creates a temporary
AttributeList just to hide the AttributeSetNode type.

I've also added a factory method to create AttributeLists from a
parallel array of AttributeSetNodes. I think this simplifies
construction of AttributeLists when rewriting function prototypes.
Previously we would test if a particular index had attributes, and
conditionally add a temporary attribute list to a vector. Now the
attribute set vector is parallel to the argument vector already that
these passes already construct.

My long term vision is to wrap AttributeSetNode* inside an AttributeSet
type that holds the enum attributes, but that will come in a follow up
change.

I haven't done any performance measurements for this change because
profiling hasn't shown that any of the affected code is hot.

Reviewers: pete, chandlerc, sanjoy, hfinkel

Reviewed By: pete

Subscribers: jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D31198

llvm-svn: 299875
2017-04-10 20:18:10 +00:00
Sanjay Patel e4159d2238 [InstCombine] improve variable names; NFCI
llvm-svn: 299871
2017-04-10 19:38:36 +00:00
Craig Topper 0d830ff7bf [InstCombine] Use commutable matchers and m_OneUse in visitSub to shorten code. Add missing test cases.
In one case I removed commute handling for a multiply with a constant since we'll eventually get the constant on the right hand side.

llvm-svn: 299863
2017-04-10 18:09:25 +00:00
Craig Topper 98851adc2a [InstCombine] Use m_c_Add to shorten some code. Add testcases for this fold since they were missing. NFC
llvm-svn: 299853
2017-04-10 16:59:40 +00:00
Sanjay Patel 570e35c157 [InstCombine] fix matching of or-of-icmps constants (PR32524)
Also, make the same change in and-of-icmps and remove a hack for detecting that case.

Finally, add some FIXME comments because the code duplication here is awful.

This should fix the remaining IR problem noted in:
https://bugs.llvm.org/show_bug.cgi?id=32524

llvm-svn: 299851
2017-04-10 16:55:57 +00:00
Craig Topper 3eec73e20b [InstCombine] Support folding of add instructions with vector constants into select operations
We currently only fold scalar add of constants into selects. This improves this to support vectors too.

Differential Revision: https://reviews.llvm.org/D31683

llvm-svn: 299847
2017-04-10 16:40:00 +00:00
Craig Topper 31cc143b51 [InstCombine] Use commutable and/or/xor matchers to simplify some code
Summary:
This is my first time using the commutable matchers so wanted to make sure I was doing it right.

Are there any other matcher tricks to further shrink this? Can we commute the whole match so we don't have to LHS and RHS separately?

Reviewers: davide, spatel

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31680

llvm-svn: 299840
2017-04-10 07:13:40 +00:00
Craig Topper 838d13e7ee [InstCombine] Make sure we preserve fast math flags when folding fp instructions into phi nodes
Summary: I noticed in the select folding code that we copied fast math flags, but did not do the same for the similar handling in phi nodes. This patch fixes that to do the same thing as select

Reviewers: spatel, davide, majnemer, hfinkel

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31690

llvm-svn: 299838
2017-04-10 07:00:10 +00:00
Craig Topper d8840d7b10 [InstCombine] use m_c_And and m_c_Xor to handle commuted versions of a transform.
llvm-svn: 299837
2017-04-10 06:53:28 +00:00
Craig Topper 7639460367 [InstCombine] Remove unnecessary dyn_cast to BinaryOperator around some matcher checks in visitXor.
The matchers themselves should be enough.

llvm-svn: 299835
2017-04-10 06:53:23 +00:00
Craig Topper 4738321f0c [InstCombine] Make the (A|B)^B -> A & ~B transform code consistent with the very similar (A&B)^B -> ~A & B code. This should be NFC except for the addition of hasOneUse check.
I think this code is still overly complicated and should use matchers, but first I wanted to make it consistent.

llvm-svn: 299834
2017-04-10 06:53:21 +00:00
Craig Topper 4f16d82d6b [InstCombine] Use m_OneUse to shorten some code. NFC
llvm-svn: 299833
2017-04-10 06:53:19 +00:00
Sanjay Patel 16a054d5c7 [InstCombine] remove dead cases from icmp pair switches; NFCI
"PredicatesFoldable" returns false for signed/unsigned mismatched pairs,
so these cases should never exist. We'll default to 'unreachable' on those 
predicate combos instead.

Most of what's left in these switches belongs in InstSimplify (and may 
already be there), so there's probably more that can be done to reduce
this code.

llvm-svn: 299829
2017-04-09 21:51:34 +00:00
Craig Topper afa07c5ef6 [InstCombine] Extend some OR combines to support vectors.
This adds support for these combines for vectors
(X^C)|Y -> (X|Y)^C iff Y&C == 0
Y|(X^C) -> (X|Y)^C iff Y&C == 0

llvm-svn: 299822
2017-04-09 06:12:41 +00:00
Craig Topper e63c21b1ba [InstCombine] Extend a canonicalization check to apply to vector constants too.
llvm-svn: 299821
2017-04-09 06:12:39 +00:00
Craig Topper 437c97622b [InstCombine] Use the SubOne helper function to shorten some code. NFC
llvm-svn: 299819
2017-04-09 06:12:34 +00:00
Craig Topper 9d1821b262 [InstCombine] rename variable for easier reading; NFC
We usually give constants a 'C' somewhere in the name...

llvm-svn: 299818
2017-04-09 06:12:31 +00:00
Craig Topper 33e0dbcc58 [InstCombine] Handle more commuted cases of ((A & B) | ~A) -> (~A | B)
llvm-svn: 299747
2017-04-07 07:32:00 +00:00
Craig Topper 72a622cac7 [InstCombine] Add more commuted patterns to support folding ((~A & B) | A) -> (A | B).
llvm-svn: 299737
2017-04-07 00:29:47 +00:00
Craig Topper a521c30dc6 [InstCombine] Remove testing assert I accidentally left in r299710.
llvm-svn: 299715
2017-04-06 21:29:43 +00:00
Craig Topper b4da6840d8 [InstCombine] When checking to see if we can turn subtracts of 2^n - 1 into xor, we only need to call computeKnownBits on the RHS not the whole subtract. While there use isMask instead of isPowerOf2(C+1)
Calling computeKnownBits on the RHS should allows us to recurse one step further. isMask is equivalent to the isPowerOf2(C+1) except in the case where C is all ones. But that was already handled earlier by creating a not which is an Xor with all ones. So this should be fine.

llvm-svn: 299710
2017-04-06 21:06:03 +00:00
Craig Topper 7226d796aa [InstCombine] Remove redundant combine from visitAnd
This combine is fully handled by SimplifyDemandedInstructionBits as of r299658 where I fixed this code to ensure the Add/Sub had only a single user. Otherwise it would fire and create additional instructions. That fix resulted in an improvement to code generated for tsan which is why I committed it before deleting.

Differential Revision: https://reviews.llvm.org/D31543

llvm-svn: 299704
2017-04-06 20:41:48 +00:00
Craig Topper 3fc1225c18 [InstCombine] Fix a case where we weren't checking that an instruction had a single use resulting in extra instructions being created.
llvm-svn: 299658
2017-04-06 16:42:46 +00:00
Sanjay Patel 50c82c4395 [InstCombine] add fold for icmp with or mask of low bits (PR32542)
We already have these 'and' folds:

// X & -C == -C -> X >  u ~C
// X & -C != -C -> X <= u ~C
//   iff C is a power of 2

...but we were missing the 'or' siblings.

http://rise4fun.com/Alive/n6

This should improve:
https://bugs.llvm.org/show_bug.cgi?id=32524
...but there are 2 or more other pieces to fix still.

Differential Revision: https://reviews.llvm.org/D31712

llvm-svn: 299570
2017-04-05 17:57:05 +00:00
Sanjay Patel 519a87a468 [InstCombine] fix formatting and variable names; NFCI
There must be some opportunity to refactor big chunks of nearly duplicated code in FoldOrOfICmps / FoldAndOfICmps.
Also, none of this works with vectors, but it should.

llvm-svn: 299568
2017-04-05 17:38:34 +00:00
Sanjay Patel 0bf0abedf6 [InstCombine] rename variable for easier reading; NFC
We usually give constants a 'C' somewhere in the name...

llvm-svn: 299474
2017-04-04 22:06:03 +00:00
Craig Topper c745b6a1f6 [InstCombine] Turn subtract of vectors of i1 into xor like we do for scalar i1. Matches what we already do for add.
llvm-svn: 299472
2017-04-04 21:44:56 +00:00
Craig Topper 86173600ec [InstCombine] Support folding and/or/xor with a constant vector RHS into selects and phis
Currently we only fold with ConstantInt RHS. This generalizes to any Constant RHS.

Differential Revision: https://reviews.llvm.org/D31610

llvm-svn: 299466
2017-04-04 20:26:25 +00:00
Craig Topper e06b6bcfa1 [InstCombine] Use setAllBits in place of getAllOnesValue since we know the bitwidths are the same. NFCI
llvm-svn: 299413
2017-04-04 05:03:02 +00:00
Zvi Rackover 82bf48d8b9 InstCombine: Use the InstSimplify hook for shufflevector
Summary: Start using the recently added InstSimplify hook for shuffles in the respective InstCombine visitor.

Reviewers: spatel, RKSimon, craig.topper, majnemer

Reviewed By: majnemer

Subscribers: majnemer, llvm-commits

Differential Revision: https://reviews.llvm.org/D31526

llvm-svn: 299412
2017-04-04 04:47:57 +00:00
Craig Topper 1604f0773b [InstCombine] Remove canonicalization for (X & C1) | C2 --> (X | C2) & (C1|C2) when C1 & C2 have common bits.
It turns out that SimplifyDemandedInstructionBits will get called earlier and remove bits from C1 first. Effectively doing (X & (C1&C2)) | C2. So by the time it got to this check there could be no common bits.

I think the DAGCombiner has the same check but its check can be executed because it handles demanded bits later. I'll look at it next.

llvm-svn: 299384
2017-04-03 20:41:47 +00:00
Craig Topper 3882613956 [DAGCombine][InstCombine] Fix inverted if condition in equivalent comments in DAGCombine and InstCombine. NFC
llvm-svn: 299378
2017-04-03 19:18:48 +00:00
Craig Topper 79120e80b8 Revert r299337 "[InstCombine] Remove redundant combine from visitAnd"
One of the tsan bots started failing at this commit. I don't see anything obviously wrong with the commit so trying this to see if it recovers.

Failing log: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-autoconf/builds/6792

llvm-svn: 299366
2017-04-03 17:22:23 +00:00
Sanjay Patel 77bf622db6 [InstCombine] fix formatting for foldLogOpOfMaskedICmps and related bits; NFCI
1. Improve enum, function, and variable names.
2. Improve comments.
3. Fix variable capitalization.
4. Run clang-format.

As an existing code comment suggests, this should work with vector types / splat constants too,
so making this look right first will reduce the diffs needed for that change.

llvm-svn: 299365
2017-04-03 16:53:12 +00:00
Craig Topper d33ee1b960 [APInt] Move isMask and isShiftedMask out of APIntOps and into the APInt class. Implement them without memory allocation for multiword
This moves the isMask and isShiftedMask functions to be class methods. They now use the MathExtras.h function for single word size and leading/trailing zeros/ones or countPopulation for the multiword size. The previous implementation made multiple temorary memory allocations to do the bitwise arithmetic operations to match the MathExtras.h implementation.

Differential Revision: https://reviews.llvm.org/D31565

llvm-svn: 299362
2017-04-03 16:34:59 +00:00
Craig Topper d0b053d229 [InstCombine] Make foldOpWithConstantIntoOperand take a BinaryOperator instead of a generic Instruction.
It blindly assumes there are two operands so make it explicit.

llvm-svn: 299351
2017-04-03 07:08:08 +00:00
Craig Topper 07944f891c [InstCombine] Remove a And transform that should be handled by SimplifyDemandedInstructionBits. NFCI
llvm-svn: 299349
2017-04-03 06:02:09 +00:00
Craig Topper 70e4f434ae [InstCombine] Make InstCombiner::OptAndOp take a BinaryOperator instead of an Instruction.
The callers have already performed the necessary cast before calling. This allows us to remove a comment that says the instruction must be a BinaryOperator and make it explicit in the argument type.

Had to add a default case to the switch because BinaryOperator::getOpcode() returns a BinaryOps enum.

llvm-svn: 299339
2017-04-02 17:57:30 +00:00
Craig Topper d133591a7e [InstCombine] Remove redundant combine from visitAnd
As far as I can tell this combine is fully handled by SimplifyDemandedInstructionBits.

I was only looking at this because it is the only user of APIntOps::isShiftedMask which is itself broken. As demonstrated by r299187. I was going to fix isShiftedMask and needed to make sure we had coverage for the new cases it would expose to this combine. But looks like we can nuke it instead.

Differential Revision: https://reviews.llvm.org/D31543

llvm-svn: 299337
2017-04-02 17:34:30 +00:00
Craig Topper 47fd2de304 [APInt] Fix bugs in isShiftedMask to match behavior of the similar function in MathExtras.h
This removes a parameter from the routine that was responsible for a lot of the issue. It was a bit count that had to be set to the BitWidth of the APInt and would get passed to getLowBitsSet. This guaranteed the call to getLowBitsSet would create an all ones value. This was then compared to (V | (V-1)). So the only shifted masks we detected had to have the MSB set.

The one in tree user is a transform in InstCombine that never fires due to earlier transforms covering the case better. I've submitted a patch to remove it completely, but for now I've just adapted it to the new interface for isShiftedMask.

llvm-svn: 299273
2017-03-31 22:23:42 +00:00
Craig Topper e625d74271 [InstCombine] When adding an Instruction and its Users to the worklist at the same time, make sure we put the Users in first. Then put in the instruction.
This way we ensure we immediately revisit the instruction and do any additional optimizations before visiting the users. Otherwise we might visit the users, then the instruction, then users again, then instruction again.

llvm-svn: 299267
2017-03-31 21:35:30 +00:00
Craig Topper 885fa12e8a [APInt] Remove shift functions from APIntOps namespace. Replace the few users with the APInt class methods. NFCI
llvm-svn: 299248
2017-03-31 20:01:16 +00:00
Joerg Sonnenberger 28bed106e0 Do not translate rint into nearbyint, but truncate it like nearbyint.
A common way to implement nearbyint is by fiddling with the floating
point environment and calling rint. This is used at least by the BSD
libm and musl. As such, canonicalizing the latter to the former will
create infinite loops for libm and generally pessimize performance, at
least when the generic C versions are used.

This change preserves the rint in the libcall translation and also
handles the domain truncation logic, so that rint with float argument
will be reduced to rintf etc.

llvm-svn: 299247
2017-03-31 19:58:07 +00:00
Dehao Chen fed890ea3a Fix the InstCombine to reserve the VP metadata and sets correct call count.
Summary: Currently the VP metadata was dropped when InstCombine converts a call to direct call. This patch converts the VP metadata to branch_weights so that its hotness is recorded.

Reviewers: eraman, davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31344

llvm-svn: 299228
2017-03-31 15:59:52 +00:00
Craig Topper 79e5bc528d [InstCombine] Fix typo last->least. NFC
llvm-svn: 299123
2017-03-30 22:28:55 +00:00
Simon Pilgrim 68168d17b9 Spelling mistakes in comments. NFCI.
Based on corrections mentioned in patch for clang for PR27635

llvm-svn: 299072
2017-03-30 12:59:53 +00:00
Matthew Simpson c8f0aeccda [InstCombine] Correct the check for vector GEPs
Some of the GEP combines (e.g., descaling) can't handle vector GEPs. We have an
existing check that attempts to bail out if given a vector GEP. However, the
check only tests the GEP's pointer operand. A GEP results in a vector of
pointers if at least one of its operands is vector-typed (e.g., its pointer
operand could be a scalar, but its index could be a vector). We should just
check the type of the GEP itself. This should fix PR32414.

Reference: https://bugs.llvm.org/show_bug.cgi?id=32414
Differential Revision: https://reviews.llvm.org/D31470

llvm-svn: 299017
2017-03-29 18:23:08 +00:00
Anna Thomas 923e574bff [InstCombine] For select rule, use positive check of constant int for select operand. NFCI
llvm-svn: 298906
2017-03-28 09:32:24 +00:00
Anna Thomas f57ae33381 [InstCombine] Avoid incorrect folding of select into phi nodes when incoming element is a vector type
Summary:
We are incorrectly folding selects into phi nodes when the incoming value of a phi
node is a constant vector. This optimization is done in `FoldOpIntoPhi` when the
select condition is a phi node with constant incoming values.
Without the fix, we are miscompiling (i.e. incorrectly folding the
select into the phi node) when the vector contains non-zero
elements.
This patch fixes the miscompile and we will correctly fold based on the
select vector operand (see added test cases).

Reviewers: majnemer, sanjoy, spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31189

llvm-svn: 298845
2017-03-27 13:52:51 +00:00
Craig Topper 47596dd4cc [InstCombine] Change the interface of SimplifyDemandedBits so that it takes the instruction and operand instead of the Use.
The first thing it did was get the User for the Use to get the instruction back. This requires looking through the Uses for the User using the waymarking walk. That's pretty fast, but its probably still better to just pass the Instruction we already had.

llvm-svn: 298772
2017-03-25 06:52:52 +00:00
Craig Topper 8fbb74b5b2 Revert r298711 "[InstCombine] Provide a way to calculate KnownZero/One for Add/Sub in SimplifyDemandedUseBits without recursing into ComputeKnownBits"
Tsan bot is failing.

llvm-svn: 298745
2017-03-24 22:12:10 +00:00
Matt Arsenault 4c7795dd31 AMDGPU: Fold rcp/rsq of undef to undef
llvm-svn: 298725
2017-03-24 19:04:57 +00:00
Craig Topper d4521c2fc2 [InstCombine] Provide a way to calculate KnownZero/One for Add/Sub in SimplifyDemandedUseBits without recursing into ComputeKnownBits
SimplifyDemandedUseBits for Add/Sub already recursed down LHS and RHS for simplifying bits. If that didn't provide any simplifications we fall back to calling computeKnownBits which will recurse again. Instead just take the known bits for LHS and RHS we already have and call into a new function in ValueTracking that can calculate the known bits given the LHS/RHS bits.

llvm-svn: 298711
2017-03-24 16:56:51 +00:00
Craig Topper 36f2e0eee8 [InstCombine] Use range-based for loop. NFC
llvm-svn: 298680
2017-03-24 02:58:02 +00:00
Craig Topper df73e7c5b7 [InstCombine] Fix 80 column violation I accidentally introduced. NFC
llvm-svn: 298679
2017-03-24 02:57:59 +00:00
Craig Topper 74494d0179 [InstCombine] Remove some code from visitAnd that dealt with trying to reduce the LHS of a sub to 0. This should now be fully handled by SimplifyDemandedInstructionBits now.
Now that we call ShrinkDemandedConstant on the RHS of sub this should be taken care of. This code doesn't trigger on any in tree regressions, but did before ShrinkDemandedConstant was added to the RHS.

llvm-svn: 298644
2017-03-23 21:00:13 +00:00
Sanjay Patel 2f602cea41 [InstCombine] canonicalize insertelement of scalar constant ahead of insertelement of variable
insertelement (insertelement X, Y, IdxC1), ScalarC, IdxC2 -->
insertelement (insertelement X, ScalarC, IdxC2), Y, IdxC1

As noted in the code comment and seen in the test changes, the motivation is that by pulling
constant insertion up, we may be able to constant fold some insertelement instructions.

Differential Revision: https://reviews.llvm.org/D31196

llvm-svn: 298520
2017-03-22 17:10:44 +00:00
Craig Topper 07f2915ad8 [InstCombine] Teach SimplifyDemandedUseBits to shrink Constants on the left side of subtracts
Summary: Subtracts can have constants on the left side, but we don't shrink them based on demanded bits. This patch fixes that to match the right hand side.

Reviewers: davide, majnemer, spatel, sanjoy, hfinkel

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31119

llvm-svn: 298478
2017-03-22 04:03:53 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Artur Pilipenko 4cc6130f52 NFC. InstCombiner::visitFAdd extract LHSIntVal/RHSIntVal local variables
llvm-svn: 298359
2017-03-21 11:32:15 +00:00
Matt Arsenault 6b00d40900 InstCombine: Check source value precision when reducing cast intrinsic
Missed this check when porting from the libcall version.

llvm-svn: 298312
2017-03-20 21:59:24 +00:00
Craig Topper d92d2fc763 [InstCombine] Print a debug message when we constant fold an operand during worklist creation
InstCombine tries to constant fold instruction operands during worklist building, but we don't print that we're doing this.

We also set a change flag here that causes us to rebuild and rerun the worklist one more time even if processing the worklist itself created no additional changes. So in the log I saw two inst combine runs that visited all instructions without printing that anything was changed. I may be submitting another patch to remove the change flag unless I can find some reason why we should be doing that.

Differential Revision: https://reviews.llvm.org/D31091

llvm-svn: 298264
2017-03-20 16:31:14 +00:00
Craig Topper ff9749f759 [InstCombine] Remove duplicate code in SimplifyDemandedUseBits for URem. NFC
llvm-svn: 298231
2017-03-19 21:45:57 +00:00
Craig Topper 3a86a04404 [InstCombine] Use setHighBits/setLowBits/setBitsFrom in place of getLowBitsSet/getHighBitsSet.
llvm-svn: 298204
2017-03-19 05:49:16 +00:00
Adrian Prantl 47ea6478ed Salvage debug info from instructions about to be deleted
[Reapplies r297971 and punting on finding a better API for findDbgValues()]

This patch improves debug info quality in InstCombine by looking at
values that are about to be deleted, checking whether there are any
dbg.value instrinsics referring to them, and potentially encoding the
semantics of the deleted instruction into the dbg.value's
DIExpression.

In the example in the testcase (which was extracted from XNU) there is a sequence of

 %4 = load %struct.entry*, %struct.entry** %next2, align 8, !dbg !41
 %5 = bitcast %struct.entry* %4 to i8*, !dbg !42
 %add.ptr4 = getelementptr inbounds i8, i8* %5, i64 -8, !dbg !43
 %6 = bitcast i8* %add.ptr4 to %struct.entry*, !dbg !44
 call void @llvm.dbg.value(metadata %struct.entry* %6, i64 0, metadata !20, metadata !21), !dbg 34

When these instructions are eliminated by instcombine one after
another, we can still salvage the otherwise dead debug info:

- Bitcasts have no effect, so have the dbg.value point to operand(0)
- Loads can be expressed via a DW_OP_deref
- Constant gep instructions can be replaced by DWARF expression arithmetic

The API introduced by this patch is not specific to instcombine and
can be useful in other places, too.

rdar://problem/30725338

Differential Revision: https://reviews.llvm.org/D30919

llvm-svn: 297994
2017-03-16 21:14:09 +00:00
Sanjay Patel 6105bb5eaf [InstCombine] avoid breaking up bitcasted vector min/max patterns (PR32306)
As the related tests show, we're not canonicalizing to this form for scalars or vectors yet,
but this solves the immediate problem in:
https://bugs.llvm.org/show_bug.cgi?id=32306

llvm-svn: 297989
2017-03-16 20:42:45 +00:00
Adrian Prantl fa9e84eb6d Revert commit r297971 because of issues reported by msan.
llvm-svn: 297982
2017-03-16 20:11:54 +00:00
Adrian Prantl 4377314a98 Salvage debug info from instructions about to be deleted
This patch improves debug info quality in InstCombine by looking at
values that are about to be deleted, checking whether there are any
dbg.value instrinsics referring to them, and potentially encoding the
semantics of the deleted instruction into the dbg.value's
DIExpression.

In the example in the testcase (which was extracted from XNU) there is a sequence of

  %4 = load %struct.entry*, %struct.entry** %next2, align 8, !dbg !41
  %5 = bitcast %struct.entry* %4 to i8*, !dbg !42
  %add.ptr4 = getelementptr inbounds i8, i8* %5, i64 -8, !dbg !43
  %6 = bitcast i8* %add.ptr4 to %struct.entry*, !dbg !44
  call void @llvm.dbg.value(metadata %struct.entry* %6, i64 0, metadata !20, metadata !21), !dbg 34

When these instructions are eliminated by instcombine one after
another, we can still salvage the otherwise dead debug info:

- Bitcasts have no effect, so have the dbg.value point to operand(0)
- Loads can be expressed via a DW_OP_deref
- Constant gep instructions can be replaced by DWARF expression arithmetic

The API introduced by this patch is not specific to instcombine and
can be useful in other places, too.

rdar://problem/30725338

Differential Revision: https://reviews.llvm.org/D30919

llvm-svn: 297971
2017-03-16 18:22:52 +00:00
Bjorn Pettersson c98dabb1a0 [InstCombine] Liberate assert in InstCombiner::visitZExt
Summary:
The call to canEvaluateZExtd in InstCombiner::visitZExt may
return with BitsToClear == SrcTy->getScalarSizeInBits(), but
there is an assert that BitsToClear should be smaller than
SrcTy->getScalarSizeInBits().

I have a test case that triggers the assert, but it only happens
for my downstream target. I've not been able to trigger it for
any upstream target.

The assert triggered for a piece of code such as this
  %shr1 = lshr i16 undef, 15
  ...
  %shr2 = lshr i16 %shr1, 1
  %conv = zext i16 %shr2 to i32

Normally the lshr instructions are constant folded before we
visit the zext (that is why it is so hard to reproduce).
The original pattern, before instcombine, is of course a lot more
complicated in my test case. The shift count in the second lshr
is for example determined by the outcome of a PHI instruction.
It seems like other rewrites by instcombine leads up to
the pattern above. And then the zext is pulled from the
worklist, and visited (hitting the assert), before we detect
that the lshr instrucions can be constant folded.

Anyway, since the canEvaluateZExtd may return with BitsToClear
equal to SrcTy->getScalarSizeInBits(), and since the rewrite
that converts the expression type to avoid a zero extend works
also for the case where SrcBitsKept ends up being zero, then
it should be OK to liberate the assert to
  assert(BitsToClear <= SrcTy->getScalarSizeInBits() &&
         "Unreasonable BitsToClear");

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, llvm-commits

Differential Revision: https://reviews.llvm.org/D30993

llvm-svn: 297952
2017-03-16 13:22:01 +00:00
Sanjay Patel a0a5682d00 [InstCombine] improve readability; NFCI
llvm-svn: 297755
2017-03-14 17:27:27 +00:00
Matt Arsenault d81f557fe2 AMDGPU: Fold icmp/fcmp into icmp intrinsic
The typical use is a library vote function which
compares to 0. Fold the user condition into the intrinsic.

llvm-svn: 297650
2017-03-13 18:14:02 +00:00
Matt Arsenault a3bdd8f27b AMDGPU: Fix insertion point when reducing load intrinsics
The insertion point may be later than the next instruction,
so it is necessary to set it when replacing the call.

llvm-svn: 297439
2017-03-10 05:25:49 +00:00
Matt Arsenault efe949cc67 AMDGPU: Support for SimplifyDemandedVectorElts for load intrinsics
llvm-svn: 297408
2017-03-09 20:34:27 +00:00
Sanjay Patel 62906af379 [InstCombine] avoid crashing on shuffle shrinkage when input type is not same as result type
llvm-svn: 297280
2017-03-08 15:02:23 +00:00
Sanjay Patel fe9705149b [InstCombine] shrink truncated insertelement into undef vector
This is the 2nd part of solving:
http://lists.llvm.org/pipermail/llvm-dev/2017-February/110293.html

D30123 moves the trunc ahead of the shuffle, and this moves the trunc ahead of the insertelement. 
We're limiting this transform to undef rather than any constant to avoid backend problems.

Differential Revision: https://reviews.llvm.org/D30137

llvm-svn: 297242
2017-03-07 23:27:14 +00:00
Sanjay Patel 53fa17a014 [InstCombine] shrink truncated splat shuffle (2nd try)
This was committed at r297155 and reverted at r297166 because of an
over-reaching clang test. That should be fixed with r297189.

This is one part of solving a recent bug report:
http://lists.llvm.org/pipermail/llvm-dev/2017-February/110293.html

This keeps with our general approach: changing arbitrary shuffles is off-limts,
but changing splat is ok. The transform is very similar to the existing
shrinkBitwiseLogic() canonicalization.

Differential Revision: https://reviews.llvm.org/D30123

llvm-svn: 297232
2017-03-07 21:45:16 +00:00
Sanjay Patel 6d30606168 revert r297155 because there's a clang test that depends on InstCombine:
tools/clang/test/CodeGen/zvector.c

llvm-svn: 297166
2017-03-07 17:41:45 +00:00
Sanjay Patel defdb7bed5 [InstCombine] shrink truncated splat shuffle
This is one part of solving a recent bug report:
http://lists.llvm.org/pipermail/llvm-dev/2017-February/110293.html

This keeps with our general approach: changing arbitrary shuffles is off-limts, 
but changing splat is ok. The transform is very similar to the existing 
shrinkBitwiseLogic() canonicalization.

Differential Revision: https://reviews.llvm.org/D30123

llvm-svn: 297155
2017-03-07 16:10:36 +00:00
Sanjay Patel c3b4735b6f [InstCombine] use dyn_cast instead of isa+cast; NFCI
llvm-svn: 297092
2017-03-06 23:25:28 +00:00
Simon Pilgrim e938a152c5 Use APInt::getLowBitsSet instead of APInt::getBitsSet for lower bit mask creation
llvm-svn: 296882
2017-03-03 16:56:33 +00:00
Bjorn Pettersson e5027cfbcc [InstCombine] Avoid faulty combines of select-cmp-br
Summary:
When InstCombine is optimizing certain select-cmp-br patterns
it replaces the result of the select in uses outside of the
basic block containing the select. This is only legal if the
path from the select to the outside use is disjoint from all
other paths out from the originating basic block.

The problem found was that InstCombiner::replacedSelectWithOperand
did not consider the case when both edges out from the br pointed
to the same label. In that case the paths aren't disjoint and the
transformation is illegal. This patch avoids the faulty rewrites
by verifying that there is a single flow to the successor where
we want to replace uses.

Reviewers: llvm-commits, spatel, majnemer

Differential Revision: https://reviews.llvm.org/D30455

llvm-svn: 296752
2017-03-02 15:18:58 +00:00
Mikael Holmen 760dc9aba7 Remove sometimes faulty rewrite of memcpy in instcombine.
Summary:
Solves PR 31990.

The bad rewrite could replace a memcpy of one word with
 store i4 -1
while it should actually be
 store i8 -1

Hopefully opt and llc has improved enough so the original optimization
done by the code isn't needed anymore.

One already existing testcase is affected. It originally tested that
the memcpy was replaced with
 load double
but since we now remove that rewrite it will be
 load i64
instead.

Patch suggestion by Eli Friedman.

Reviewers: eli.friedman, majnemer, efriedma

Reviewed By: efriedma

Subscribers: efriedma, llvm-commits

Differential Revision: https://reviews.llvm.org/D30254

llvm-svn: 296585
2017-03-01 06:45:20 +00:00
Matt Arsenault cdb468c0f9 AMDGPU: Basic folds for fmed3 intrinsic
Constant fold, canonicalize constants to RHS,
reduce to minnum/maxnum when inputs are nan/undef.

llvm-svn: 296409
2017-02-27 23:08:49 +00:00
Yaxun Liu e6d1ce59c0 [InstCombine] Fix bug in pointer replacement
This optimisation was crashing when there was a chain of more than one bitcast
instruction to replace, as a result of the changes in D27283.

Patch by James Price.

Differential Revision: https://reviews.llvm.org/D30347

llvm-svn: 296163
2017-02-24 20:27:25 +00:00
Sanjay Patel ec9a8de0e6 [InstCombine] don't try SimplifyDemandedInstructionBits from zext/sext because it's slow and unnecessary
This one seems more obvious than D30270 that it can't make improvements because an extension always needs
all of the incoming bits. There's one specific transform in SimplifyDemandedInstructionBits of converting
a sext to a zext when the sign-bit is known zero, but that is handled explicitly in visitSext() with
ComputeSignBit().

Like D30270, there are no IR differences (other than instruction names) for the case in PR32037:
https://bugs.llvm.org//show_bug.cgi?id=32037
...and no regression test differences.

Zext/sext are a smaller part of the profile, but this still appears to shave off another 0.5% or so from
'opt -O2'.

Differential Revision: https://reviews.llvm.org/D30280

llvm-svn: 296129
2017-02-24 15:18:42 +00:00
Sanjay Patel 68e4cb3c86 [InstCombine] use loop instead of recursion to peek through FPExt; NFCI
llvm-svn: 295992
2017-02-23 16:39:51 +00:00
Sanjay Patel adf2ab16e4 [InstCombine] use 'match' to reduce code; NFCI
llvm-svn: 295991
2017-02-23 16:26:03 +00:00
Matt Arsenault d4bca1e9ef AMDGPU: Replace disabled exp inputs with undef
llvm-svn: 295914
2017-02-23 00:44:03 +00:00
Matt Arsenault f5262256a1 AMDGPU: Add replacement bfe intrinsics
llvm-svn: 295899
2017-02-22 23:04:58 +00:00
Sanjay Patel 4805ce0b17 [InstCombine] don't try SimplifyDemandedInstructionBits from add/sub because it's slow and unlikely to succeed
Notably, no regression tests change when we remove these calls, and these are expensive calls.

The motivation comes from the general acknowledgement that the compiler is getting slower:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/109188.html
http://lists.llvm.org/pipermail/llvm-dev/2016-December/108279.html

And specifically the test case attached to PR32037:
https://bugs.llvm.org//show_bug.cgi?id=32037

Profiling the middle-end (opt) part of the compile:
$ ./opt -O2 row_common.bc -o /dev/null

...visitAdd and visitSub are near the top of the instcombine list, and the calls to SimplifyDemandedInstructionBits()
are high within each of those. Those calls account for 1%+ of the opt time in either debug or release profiles. And 
that's the rough win I see from this patch when testing opt built release from r295864 on an iMac with Haswell 4GHz
(model 4790K).

It seems unlikely that we'd be able to eliminate add/sub or change their operands given that add/sub normally affect
all bits, and the PR32037 example shows no IR difference after this change using -O2.

Also worth noting - the code comment in visitAdd:
// This handles stuff like (X & 254)+1 -> (X&254)|1
...isn't true. That transform is handled later with a call to haveNoCommonBitsSet().

Differential Revision: https://reviews.llvm.org/D30270

llvm-svn: 295898
2017-02-22 23:01:12 +00:00
Matt Arsenault 1f17c66890 AMDGPU: Add cvt.pkrtz intrinsic
Convert llvm.SI.packf16 test uses

llvm-svn: 295797
2017-02-22 00:27:34 +00:00
Sanjay Patel cb731f1538 [InstCombine] canonicalize non-obivous forms of integer min/max
This is part of trying to clean up our handling of min/max patterns in IR.
By converting these to canonical form, we're more likely to recognize them
because there are various places in InstCombine that don't use 
matchSelectPattern or m_SMax and friends.

The backend fixups referenced in the now deleted TODO comment were added with:
https://reviews.llvm.org/rL291392
https://reviews.llvm.org/rL289738

If there's any codegen fallout from this change, we should be able to address
it in DAGCombiner or target-specific lowering. 

llvm-svn: 295758
2017-02-21 19:33:53 +00:00
Anna Thomas ec36f3b79a [InstCombine] Do not exercise nested max/min pattern on abs
Summary:
This is a fix for assertion failure in
`getInverseMinMaxSelectPattern` when ABS is passed in as a select pattern.

We should not be invoking the simplification rule for
ABS(MIN(~ x,y))) or ABS(MAX(~x,y)) combinations.

Added a test case which would cause an assertion failure without the patch.

Reviewers: sanjoy, majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30051

llvm-svn: 295719
2017-02-21 14:40:28 +00:00
Sanjay Patel 53c5c3d65d [InstCombine] add nsw/nuw X, signbit --> or X, signbit
Changing to 'or' (rather than 'xor' when no wrapping flags are set)
allows icmp simplifies to happen as expected.

Differential Revision: https://reviews.llvm.org/D29729

llvm-svn: 295574
2017-02-18 22:20:09 +00:00
Eugene Leviant 958fcd7502 InstCombine: fix extraction when performing vector/array punning
Differential revision: https://reviews.llvm.org/D29491

llvm-svn: 295429
2017-02-17 07:36:03 +00:00
Matt Arsenault 920576042d InstCombine: Canonicalize fast fmuladd to fmul + fadd
llvm-svn: 295353
2017-02-16 18:46:24 +00:00
Craig Topper 3731f4d173 [AVX-512][InstCombine] Teach InstCombine to optimize 512-bit packss/packus intrinsics like it does 128/256-bit.
llvm-svn: 295294
2017-02-16 07:35:23 +00:00
Sanjay Patel 845ea963aa [InstCombine] improve formatting; NFC
llvm-svn: 295237
2017-02-15 21:31:34 +00:00
Sanjay Patel 45b7e69fef [InstCombine] fold icmp sgt/slt (add nsw X, C2), C --> icmp sgt/slt X, (C - C2)
I found one special case of this transform for 'slt 0', so I removed that and added the general transform.

Alive code to check correctness:

Name: slt_no_overflow
Pre: WillNotOverflowSignedSub(C1, C2)
%a = add nsw i8 %x, C2
%b = icmp slt %a, C1
  =>
%b = icmp slt %x, C1 - C2

Name: sgt_no_overflow
Pre: WillNotOverflowSignedSub(C1, C2)
%a = add nsw i8 %x, C2
%b = icmp sgt %a, C1
  =>
%b = icmp sgt %x, C1 - C2

http://rise4fun.com/Alive/MH

Differential Revision: https://reviews.llvm.org/D29774

llvm-svn: 294898
2017-02-12 16:40:30 +00:00
Benjamin Kramer 03ab8a366e [InstCombine] Move class into anonymous namespace. NFC.
This is necessary to avoid warnings from GCC.
InstCombineLoadStoreAlloca.cpp:238:7: error: 'PointerReplacer' declared
with greater visibility than the type of its field 'PointerReplacer::IC'

llvm-svn: 294794
2017-02-10 22:26:35 +00:00
Benjamin Kramer 684c87be4f [InstCombine] Silence unused variable warning in Release builds.
llvm-svn: 294788
2017-02-10 22:04:17 +00:00
Yaxun Liu ba01ed00fe Fix invalid addrspacecast due to combining alloca with global var
For function-scope variables with large initialisation list, FE usually 
generates a global variable to hold the initializer, then generates 
memcpy intrinsic to initialize the alloca. InstCombiner::visitAllocaInst 
identifies such allocas which are accessed only by reading and replaces 
them with the global variable. This is done by casting the global variable 
to the type of the alloca and replacing all references.

However, when the global variable is in a different address space which 
is disjoint with addr space 0 (e.g. for IR generated from OpenCL, 
global variable cannot be in private addr space i.e. addr space 0), casting 
the global variable to addr space 0 results in invalid IR for certain 
targets (e.g. amdgpu).

To fix this issue, when the global variable is not in addr space 0, 
instead of casting it to addr space 0, this patch chases down the uses 
of alloca until reaching the load instructions, then replaces load from 
alloca with load from the global variable. If during the chasing 
bitcast and GEP are encountered, new bitcast and GEP based on the global 
variable are generated and used in the load instructions.

Differential Revision: https://reviews.llvm.org/D27283

llvm-svn: 294786
2017-02-10 21:46:07 +00:00
Sanjay Patel f38bab73aa [InstCombine] allow (X * C2) << C1 --> X * (C2 << C1) for vectors
This fold already existed for vectors but only when 'C1' was a splat
constant (but 'C2' could be any constant). 

There were no tests for any vector constants, so I'm adding a test
that shows non-splat constants for both operands.  

llvm-svn: 294650
2017-02-09 23:13:04 +00:00
Sanjay Patel ae3b43e488 [InstCombine] use m_APInt to allow demanded bits analysis on splat constants
llvm-svn: 294628
2017-02-09 21:43:06 +00:00
Sanjay Patel 6dd2eae76a [InstCombine] add local name for repeated calls; NFC
llvm-svn: 294470
2017-02-08 16:19:36 +00:00
Igor Laevsky a9b6872908 [InstComobineCalls] Fix buildbot failures after r294453.
Some targets don't support uint64_t options. Change type to unsigned.

Differential Revision: https://reviews.llvm.org/D28909

llvm-svn: 294461
2017-02-08 15:21:48 +00:00
Igor Laevsky 900ffa34c8 [InstCombineCalls] Unfold element atomic memcpy instruction
Differential Revision: https://reviews.llvm.org/D28909

llvm-svn: 294453
2017-02-08 14:32:04 +00:00
Igor Laevsky 4b317fa24e [InstCombineCalls] Remove zero length atomic memcpy intrinsics
Differential Revision: https://reviews.llvm.org/D28909

llvm-svn: 294452
2017-02-08 14:23:47 +00:00
David Blaikie 4c01af203e Fix the -Werror build for some sign-comparisons
llvm-svn: 294331
2017-02-07 18:58:17 +00:00
Davide Italiano 2133bf5562 [InstCombine] Make max size array combine a tunable.
Requested by Sanjoy/Hal a while ago, and forgotten by me
(r283612).

llvm-svn: 294323
2017-02-07 17:56:50 +00:00
Paul Robinson 383c5c228f Merge DebugLoc on combined stores; in this case, when combining stores
from the end of two blocks, merge instead of arbitrarily picking one.

Differential Revision: http://reviews.llvm.org/D29504

llvm-svn: 294251
2017-02-06 22:19:04 +00:00
Sanjay Patel cf4c90f3d3 [InstCombine] simplify dyn_cast + isa; NFCI
llvm-svn: 294198
2017-02-06 17:16:16 +00:00
Sanjay Patel 0fe32ac256 [InstCombine] treat i1 as a special type in shouldChangeType()
This patch is based on the llvm-dev discussion here:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/109631.html

Folding to i1 should always be desirable because that's better for value tracking 
and we have special folds for i1 types.

I checked for other users of shouldChangeType() where this might have an effect, 
but we already handle the i1 case differently than other types in all of those cases.

Side note: the default datalayout includes i1, so it seems we only find this gap in 
shouldChangeType + phi folding for the case when there is (1) an explicit datalayout 
without i1, (2) casting to i1 from a legal type, and (3) a phi with exactly 2 incoming
casted operands (as Björn mentioned).

Differential Revision: https://reviews.llvm.org/D29336

llvm-svn: 294066
2017-02-03 23:13:11 +00:00
Sanjay Patel 73fc8ddb06 [InstCombine] fix operand-complexity-based canonicalization (PR28296)
The code comments didn't match the code logic, and we didn't actually distinguish the fake unary (not/neg/fneg) 
operators from arguments. Adding another level to the weighting scheme provides more structure and can help 
simplify the pattern matching in InstCombine and other places.

I fixed regressions that would have shown up from this change in:
rL290067
rL290127

But that doesn't mean there are no pattern-matching logic holes left; some combines may just be missing regression tests.

Should fix:
https://llvm.org/bugs/show_bug.cgi?id=28296

Differential Revision: https://reviews.llvm.org/D27933

llvm-svn: 294049
2017-02-03 21:43:34 +00:00
Sanjay Patel c56d1ccd79 [InstCombine] move folds for shift-shift pairs; NFCI
Although this is 'no-functional-change-intended', I'm adding tests
for shl-shl and lshr-lshr pairs because there is no existing test 
coverage for those folds.

It seems like we should be able to remove some code from foldShiftedShift()
at this point because we're handling those patterns on the general path.

llvm-svn: 293814
2017-02-01 21:31:34 +00:00
Sanjoy Das e0e5795f6b [InstCombine] Allow InstCombine to merge adjacent guards
Summary:
If there are two adjacent guards with different conditions, we can
remove one of them and include its condition into the condition of
another one. This patch allows InstCombine to merge them by the
following pattern:

    guard(a); guard(b) -> guard(a & b).

Reviewers: reames, apilipenko, igor-laevsky, anna, sanjoy

Reviewed By: sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29378

llvm-svn: 293778
2017-02-01 16:34:55 +00:00
Davide Italiano aec4617dc8 [Instcombine] Combine consecutive identical fences
Differential Revision:  https://reviews.llvm.org/D29314

llvm-svn: 293661
2017-01-31 18:09:05 +00:00
Arnold Schwaighofer c368563bd6 Don't combine stores to a swifterror pointer operand to a different type
llvm-svn: 293658
2017-01-31 17:53:49 +00:00
Sanjay Patel 2217f75ad1 fix formatting; NFC
llvm-svn: 293652
2017-01-31 17:25:42 +00:00
Silviu Baranga c6d21eba0e [InstCombine] Make sure that LHS and RHS have the same type in
transformToIndexedCompare

If they don't have the same type, the size of the constant
index would need to be adjusted (and this wouldn't be always
possible).

Alternatively we could try the analysis with the initial
RHS value, which would guarantee that the two sides have
the same type. However it is unlikely that in practice this
would pass our transformation requirements.

Fixes PR31808 (https://llvm.org/bugs/show_bug.cgi?id=31808).

llvm-svn: 293629
2017-01-31 14:04:15 +00:00
Sanjay Patel 8c5f236197 [InstCombine] enable (X <<nsw C1) >>s C2 --> X <<nsw (C1 - C2) for vectors with splat constants
llvm-svn: 293570
2017-01-30 23:35:52 +00:00
Sanjay Patel 0c39d56a60 [InstCombine] enable more lshr(shl X, C1), C2 folds for vectors with splat constants
llvm-svn: 293562
2017-01-30 23:01:05 +00:00
Sanjay Patel 373db5ba6c [InstCombine] enable (X >>?exact C1) << C2 --> X >>?exact (C1-C2) for vectors with splat constants
llvm-svn: 293524
2017-01-30 18:40:23 +00:00
Sanjay Patel 062c14af5c [InstCombine] use auto with obvious type; NFC
llvm-svn: 293508
2017-01-30 17:38:55 +00:00
Sanjay Patel 77732d5033 [InstCombine] enable (X <<nsw C1) >>s C2 --> X <<nsw (C1-C2) for vectors with splat constants
llvm-svn: 293507
2017-01-30 17:19:32 +00:00
Sanjay Patel 8e644c08ee [InstCombine] fixed to propagate 'exact' on lshr
The original shift is bigger, so this may qualify as 'obvious', 
but here's an attempt at an Alive-based proof:

Name: exact
Pre: (C1 u< C2)
%a = shl i8 %x, C1
%b = lshr exact i8 %a, C2 
  =>
%c = lshr exact i8 %x, C2 - C1
%b = and i8 %c, ((1 << width(C1)) - 1) u>> C2

Optimization is correct!

llvm-svn: 293498
2017-01-30 16:53:03 +00:00
Sanjay Patel 1196d7cd7f [InstCombine] enable lshr(shl X, C1), C2 folds for vectors with splat constants
llvm-svn: 293489
2017-01-30 16:11:40 +00:00
Sanjay Patel 062adaab83 [InstCombine] enable (X >>?,exact C1) << C2 --> X << (C2 - C1) for vectors with splats
llvm-svn: 293435
2017-01-29 17:11:18 +00:00
Sanjay Patel febcb9ce54 [InstCombine] move icmp transforms that might be recognized as min/max and inf-loop (PR31751)
This is a minimal patch to avoid the infinite loop in:
https://llvm.org/bugs/show_bug.cgi?id=31751

But the general problem is bigger: we're not canonicalizing all of the min/max forms reported
by value tracking's matchSelectPattern(), and we don't define min/max consistently. Some code
uses matchSelectPattern(), other code uses matchers like m_Umax, and others have their own
inline definitions which may be subtly different from any of the above.

The reason that the test cases in this patch need a cast op to trigger is because we don't
(yet) canonicalize all min/max forms based on matchSelectPattern() in 
canonicalizeMinMaxWithConstant(), but we do make min/max+cast transforms based on 
matchSelectPattern() in visitSelectInst().

The location of the icmp transforms that trigger the inf-loop seems arbitrary at best, so
I'm moving those behind the min/max fence in visitICmpInst() as the quick fix.

llvm-svn: 293345
2017-01-27 23:26:27 +00:00
Justin Lebar 25ebe2d767 [NVPTX] [InstCombine] Add llvm_unreachable to appease MSVC.
llvm-svn: 293253
2017-01-27 02:04:07 +00:00
Justin Lebar e3ac0fb948 [NVPTX] Fix use-after-stack-free bug in InstCombineCalls.
Introduced in r293244.

llvm-svn: 293251
2017-01-27 01:49:39 +00:00
Justin Lebar 698c31b8db [NVPTX] Upgrade NVVM intrinsics in InstCombineCalls.
Summary:
There are many NVVM intrinsics that we can't entirely get rid of, but
that nonetheless often correspond to target-generic LLVM intrinsics.

For example, if flush denormals to zero (ftz) is enabled, we can convert
@llvm.nvvm.ceil.ftz.f to @llvm.ceil.f32.  On the other hand, if ftz is
disabled, we can't do this, because @llvm.ceil.f32 will be lowered to a
non-ftz PTX instruction.  In this case, we can, however, simplify the
non-ftz nvvm ceil intrinsic, @llvm.nvvm.ceil.f, to @llvm.ceil.f32.

These transformations are particularly useful because they let us
constant fold instructions that appear in libdevice, the bitcode library
that ships with CUDA and essentially functions as its libm.

Reviewers: tra

Subscribers: hfinkel, majnemer, llvm-commits

Differential Revision: https://reviews.llvm.org/D28794

llvm-svn: 293244
2017-01-27 00:58:58 +00:00
Sanjoy Das 7516192a71 Revert a couple of InstCombine/Guard checkins
This change reverts:

r293061: "[InstCombine] Canonicalize guards for NOT OR condition"
r293058: "[InstCombine] Canonicalize guards for AND condition"

They miscompile cases like:

```
declare void @llvm.experimental.guard(i1, ...)

define void @test_guard_not_or(i1 %A, i1 %B) {
  %C = or i1 %A, %B
  %D = xor i1 %C, true
  call void(i1, ...) @llvm.experimental.guard(i1 %D, i32 20, i32 30)[ "deopt"() ]
  ret void
}
```

because they do transfer the `i32 20, i32 30` parameters to newly
created guard instructions.

llvm-svn: 293227
2017-01-26 23:38:11 +00:00
Sanjay Patel 50753f02c2 [InstCombine] fold (X >>u C) << C --> X & (-1 << C)
We already have this fold when the lshr has one use, but it doesn't need that
restriction. We may be able to remove some code from foldShiftedShift().

Also, move the similar:
(X << C) >>u C --> X & (-1 >>u C)
...directly into visitLShr to help clean up foldShiftByConstOfShiftByConst().

That whole function seems questionable since it is called by commonShiftTransforms(),
but there's really not much in common if we're checking the shift opcodes for every
fold.

llvm-svn: 293215
2017-01-26 22:08:10 +00:00
Sanjay Patel b0d96d327e [InstCombine] use m_APInt to allow (X << C) >>u C --> X & (-1 >>u C) with splat vectors
llvm-svn: 293208
2017-01-26 20:52:27 +00:00
Craig Topper b6122122c9 [X86] Add demanded elts support for the inputs to pclmul intrinsic
This intrinsic uses bit 0 and bit 4 of an immediate argument to determine which bits of its inputs to read. This patch uses this information to simplify the demanded elements of the input vectors.

Differential Revision: https://reviews.llvm.org/D28979

llvm-svn: 293151
2017-01-26 05:17:13 +00:00
Artur Pilipenko b85f7a5d99 [InstCombine] Canonicalize guards for NOT OR condition
This is a partial fix for Bug 31520 - [guards] canonicalize guards in instcombine

Reviewed By: apilipenko

Differential Revision: https://reviews.llvm.org/D29075

Patch by Maxim Kazantsev.

llvm-svn: 293061
2017-01-25 14:45:12 +00:00
Simon Pilgrim 6f6b279109 [InstCombine][SSE] Add support for PACKSS/PACKUS constant folding
Differential Revision: https://reviews.llvm.org/D28949

llvm-svn: 293060
2017-01-25 14:37:24 +00:00
Artur Pilipenko 4df4c4a4aa [InstCombine] Canonicalize guards for AND condition
This is a partial fix for Bug 31520 - [guards] canonicalize guards in instcombine

Reviewed By: apilipenko

Differential Revision: https://reviews.llvm.org/D29074

Patch by Maxim Kazantsev.

llvm-svn: 293058
2017-01-25 14:20:52 +00:00
Artur Pilipenko e812ca00bb [InstCombine] Allow InstrCombine to remove one of adjacent guards if they are equivalent
This is a partial fix for Bug 31520 - [guards] canonicalize guards in instcombine

Reviewed By: majnemer, apilipenko

Differential Revision: https://reviews.llvm.org/D29071

Patch by Maxim Kazantsev.

llvm-svn: 293056
2017-01-25 14:12:12 +00:00
Amaury Sechet d90f5f6698 Use InstCombine's builder in foldSelectCttzCtlz instead of creating a new one.
Summary: As per title. This will add the instructiions we are interested in in the worklist.

Reviewers: mehdi_amini, majnemer, andreadb

Differential Revision: https://reviews.llvm.org/D29081

llvm-svn: 292957
2017-01-24 17:48:25 +00:00
Amaury Sechet 5da456e6a1 Fix formating in foldSelectCttzCtlz. NFC
llvm-svn: 292934
2017-01-24 14:22:27 +00:00
Simon Pilgrim 78f8630ac0 [InstCombine][X86] MULDQ/MULUDQ undef -> zero
Added early out for single undef input - we were already supporting (and testing) this in the constant folding code, we just do it quicker now

Drop undef handling from demanded elts code now that we handle it fully in InstCombiner::visitCallInst

llvm-svn: 292913
2017-01-24 11:07:41 +00:00
Matt Arsenault 954a624fb9 SimplifyLibCalls: Replace more unary libcalls with intrinsics
llvm-svn: 292855
2017-01-23 23:55:08 +00:00
Simon Pilgrim f6f3a36159 [InstCombine][X86] Add MULDQ/MULUDQ constant folding support
llvm-svn: 292793
2017-01-23 15:22:59 +00:00
Simon Pilgrim bb13fdabec [InstCombine][X86] MULDQ/MULUDQ undef -> zero
Match generic mul behaviour so that <X x i64> multiply and muldq/muludq pattern act the same

llvm-svn: 292784
2017-01-23 12:07:32 +00:00
Sanjay Patel 478a83c905 [InstCombine] use m_APInt to allow ashr folds for vectors with splat constants
We may be able to assert that no shl-shl or lshr-lshr pairs ever get here
because we should have already handled those in foldShiftedShift().

llvm-svn: 292726
2017-01-21 17:59:59 +00:00
Simon Pilgrim a50a93fcd0 [InstCombine][X86] Add MULDQ/MULUDQ undef handling
llvm-svn: 292627
2017-01-20 18:20:30 +00:00
Simon Pilgrim 51b3b98e3a [InstCombine][SSE] Add DemandedElts support for PACKSS/PACKUS instructions
Simplify a packss/packus truncation based on the elements of the mask that are actually demanded.

Differential Revision: https://reviews.llvm.org/D28777

llvm-svn: 292591
2017-01-20 09:28:21 +00:00
Davide Italiano 2ef8c4e708 [InstCombine] Simplify gep (gep p, a), (b-a)
Patch by Andrea Canciani.

Differential Revision:  https://reviews.llvm.org/D27413

llvm-svn: 292506
2017-01-19 18:51:56 +00:00
Sanjay Patel 291c3d8ff2 [InstCombine] icmp Pred (shl nsw X, C1), C0 --> icmp Pred X, C0 >> C1
Try harder to fold icmp with shl nsw as discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/108749.html

This is similar to the 'shl nuw' transforms that were added with D25913.

This may eventually help solve:
https://llvm.org/bugs/show_bug.cgi?id=30773

Differential Revision: https://reviews.llvm.org/D28406

llvm-svn: 292492
2017-01-19 16:12:10 +00:00
Sanjay Patel ae23d65a7d [InstCombine] add an assert to make a shl+icmp transform assumption explicit; NFCI
llvm-svn: 292440
2017-01-18 21:16:12 +00:00
Sanjay Patel 589de5ea4e [InstCombine] remove a redundant check; NFCI
I missed deleting this check when I refactored this chunk in:
https://reviews.llvm.org/rL292260

llvm-svn: 292433
2017-01-18 20:09:59 +00:00
Simon Pilgrim fe2c0ed4cf [InstCombine][AVX2] Add DemandedElts support for VPERMD/VPERMPS shuffles
Simplify a vpermv shuffle mask based on the elements of the mask that are actually demanded.

llvm-svn: 292371
2017-01-18 14:47:49 +00:00
Simon Pilgrim a22c3a1c0f [InstCombine] Remove unnecessary intrinsics demanded elts handling
As discussed on D28777 - we don't need to handle 'all element' shuffles inside InstCombiner::visitCallInst as InstCombiner::SimplifyDemandedVectorElts will do everything we need.

llvm-svn: 292365
2017-01-18 13:44:04 +00:00
Sanjay Patel 14715b3c2a [InstCombine] refactor foldICmpShlConstant(); NFCI
This reduces the size of and increases the symmetry with the planned functional change in:
https://reviews.llvm.org/D28406

llvm-svn: 292260
2017-01-17 21:25:16 +00:00
David Majnemer de55c606d1 [InstCombine] Fold ((C1 OP zext(X)) & C2) -> zext((C1 OP X) & C2)
This further extends r292179 to support additional binary operators
beyond subtraction.

llvm-svn: 292238
2017-01-17 18:08:06 +00:00
Sanjay Patel 5424bd2625 [InstCombine] reduce indent; NFCI
llvm-svn: 292230
2017-01-17 16:59:09 +00:00
Simon Pilgrim d4eb800b03 [InstCombine][X86][AVX] Add DemandedElts support for VPERMILPD/VPERMILPS instructions
Simplify a vpermilvar shuffle mask based on the elements of the mask that are actually demanded.

llvm-svn: 292209
2017-01-17 11:35:03 +00:00
Sanjoy Das 679bc32c6a [InstCombine] Don't DSE across readnone functions that may throw
Summary: Depends on D28740

Reviewers: dberlin, chandlerc, hfinkel, majnemer

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D28742

llvm-svn: 292197
2017-01-17 05:45:09 +00:00
David Majnemer 36d382b773 [InstCombine] Fold ((C1-zext(X)) & C2) -> zext((C1-X) & C2)
This is valid if C2 fits within the bitwidth of X thanks to two's
complement modulo arithmetic.

llvm-svn: 292179
2017-01-17 00:45:57 +00:00
Matt Arsenault 7233344c28 SimplifyLibCalls: Replace fabs libcalls with intrinsics
Add missing fabs(fpext) optimzation that worked with the call,
and also fixes it creating a second fpext when there were multiple
uses.

llvm-svn: 292172
2017-01-17 00:10:40 +00:00
Sanjay Patel da5682afdd [InstCombine] use m_APInt instead of faking it
llvm-svn: 292164
2017-01-16 21:24:41 +00:00
Sanjay Patel 65cce20caa [InstCombine] fix names in canEvaluateShiftedShift(); NFC
It's not clear what 'First' and 'Second' mean, so use 'Inner' and 'Outer'
to match foldShiftedShift() and add comments with formulas, so it's easier
to see what's going on.

llvm-svn: 292153
2017-01-16 20:05:26 +00:00
Sanjay Patel ab8b32de71 [InstCombine] use m_APInt to allow shift-shift folds for vectors with splat constants
Some existing 'FIXME' tests are still not folded because of splat holes in value tracking.

llvm-svn: 292151
2017-01-16 19:35:45 +00:00
Sanjay Patel 646734a6cd [InstCombine] refactor shift-of-shift folds; NFCI
Reduces code duplication and makes it easier to extend these folds for vectors.

llvm-svn: 292145
2017-01-16 17:27:50 +00:00
Simon Pilgrim 73a68c25a0 [InstCombine][SSE] Add DemandedElts support for PSHUFB instructions
Simplify a pshufb shuffle mask based on the elements of the mask that are actually demanded.

Differential Revision: https://reviews.llvm.org/D28745

llvm-svn: 292101
2017-01-16 11:30:41 +00:00
Sanjay Patel 20aaf58543 [InstCombine] fix formatting; NFC
llvm-svn: 292073
2017-01-15 17:55:35 +00:00
Sanjay Patel 5f8451afad [InstCombine] use m_APInt to allow ashr folds for vectors with splat constants
llvm-svn: 292064
2017-01-15 16:38:19 +00:00
Chandler Carruth ca68a3ec47 [PM] Introduce an analysis set used to preserve all analyses over
a function's CFG when that CFG is unchanged.

This allows transformation passes to simply claim they preserve the CFG
and analysis passes to check for the CFG being preserved to remove the
fanout of all analyses being listed in all passes.

I've gone through and removed or cleaned up as many of the comments
reminding us to do this as I could.

Differential Revision: https://reviews.llvm.org/D28627

llvm-svn: 292054
2017-01-15 06:32:49 +00:00
Chandler Carruth 2f19a324cb [PM] The assumption cache is fundamentally designed to be self-updating,
mark it as never invalidated in the new PM.

The old PM already required this to work, and after a discussion with
Hal this seems to really be the only sensible answer. The cache
gracefully degrades as the IR is mutated, and most things which do this
should already be incrementally updating the cache.

This gets rid of a bunch of logic preserving and testing the
invalidation of this analysis.

llvm-svn: 292039
2017-01-15 00:26:18 +00:00
Chandler Carruth 5edfd4d99e [PM] Fix instcombine's analysis preservation in the new pass manager to
cover domtree and alias analysis. These are the pretty clear analyses
that we would always want to survive this pass.

To make these survive, we also need to preserve the assumption cache.

Added a test that verifies the important bits of this preservation.

llvm-svn: 292037
2017-01-14 23:25:22 +00:00
Sanjay Patel ca3124f74b [InstCombine] clean up visitAshr(); NFCI
llvm-svn: 292036
2017-01-14 23:13:50 +00:00
Sanjay Patel 40f401776b [InstCombine] optimize unsigned icmp of increment
Allows LLVM to optimize sequences like the following:

%add = add nuw i32 %x, 1
%cmp = icmp ugt i32 %add, %y

Into:

%cmp = icmp uge i32 %x, %y

Previously, only signed comparisons were being handled.

Decrements could also be handled, but 'sub nuw %x, 1' is currently canonicalized to
'add %x, -1' in InstCombineAddSub, losing the nuw flag. Removing that canonicalization
seems like it might have far-reaching ramifications so I kept this simple for now.

Patch by Matti Niemenmaa!

Differential Revision: https://reviews.llvm.org/D24700

llvm-svn: 291975
2017-01-13 23:25:46 +00:00
Sanjay Patel 2d4b456427 [InstCombine] use m_APInt to allow lshr folds for vectors with splat constants
llvm-svn: 291972
2017-01-13 23:04:10 +00:00
Sanjay Patel acd24c7b6a [InstCombine] use 'match' and other clean-up; NFCI
llvm-svn: 291937
2017-01-13 18:52:10 +00:00
Sanjay Patel b22f6c5f26 [InstCombine] use m_APInt to allow shl folds for vectors with splat constants
llvm-svn: 291934
2017-01-13 18:39:09 +00:00
Sanjay Patel cf08203105 [InstCombine] use Op0/Op1 local variables more consistently with shifts; NFC
llvm-svn: 291923
2017-01-13 18:08:25 +00:00
Sanjay Patel 5178363687 [InstCombine] if the condition of a select may be known via assumes, eliminate the select
This is a limited solution for PR31512:
https://llvm.org/bugs/show_bug.cgi?id=31512

The motivation is that we will need to increase usage of llvm.assume and/or metadata to solve PR28430:
https://llvm.org/bugs/show_bug.cgi?id=28430

...and this kind of simplification is needed to take advantage of that extra information.

The 'not' test case would be handled by:
https://reviews.llvm.org/D28485

Differential Revision:
https://reviews.llvm.org/D28337

llvm-svn: 291915
2017-01-13 17:02:42 +00:00
Robert Lougher f5df7a18dd [DebugInfo] Add const to DILocation variable declaration; NFC.
llvm-svn: 291785
2017-01-12 18:29:28 +00:00
Hal Finkel 8a9a783f2c Make processing @llvm.assume more efficient - Add affected values to the assumption cache
Here's my second try at making @llvm.assume processing more efficient. My
previous attempt, which leveraged operand bundles, r289755, didn't end up
working: it did make assume processing more efficient but eliminating the
assumption cache made ephemeral value computation too expensive. This is a
more-targeted change. We'll keep the assumption cache, but extend it to keep a
map of affected values (i.e. values about which an assumption might provide
some information) to the corresponding assumption intrinsics. This allows
ValueTracking and LVI to find assumptions relevant to the value being queried
without scanning all assumptions in the function. The fact that ValueTracking
started doing O(number of assumptions in the function) work, for every
known-bits query, has become prohibitively expensive in some cases.

As discussed during the review, this is a pragmatic fix that, longer term, will
likely be replaced by a more-principled solution (perhaps based on an extended
SSA form).

Differential Revision: https://reviews.llvm.org/D28459

llvm-svn: 291671
2017-01-11 13:24:24 +00:00
Sanjay Patel db0938fd9a [InstCombine] add a wrapper for a common pair of transforms; NFCI
Some of the callers are artificially limiting this transform to integer types;
this should make it easier to incrementally remove that restriction.

llvm-svn: 291620
2017-01-10 23:49:07 +00:00
Matt Arsenault 3f509042b0 InstCombine: Set operands instead of creating new call
llvm-svn: 291612
2017-01-10 23:17:52 +00:00
Matt Arsenault fdb78f8bae InstCombine: fdiv -x, -y -> fdiv x, y
llvm-svn: 291611
2017-01-10 23:08:54 +00:00
Sanjay Patel 940c06188e fix comment typos; NFC
llvm-svn: 291447
2017-01-09 16:27:56 +00:00
Matt Arsenault 3bdd75d01e InstCombine: Fold cos(-x) -> cos(x)
Also cos(fabs(x)) -> cos(x)

llvm-svn: 291022
2017-01-04 22:49:03 +00:00
David Majnemer cb892e9066 [InstCombine] Move casts around shift operations
It is possible to perform a left shift before zero extending if the
shift would only shift out zeros.

llvm-svn: 290928
2017-01-04 02:21:34 +00:00
David Majnemer 022d2a563b [InstCombine] Combine adds across a zext
We can perform the following:
(add (zext (add nuw X, C1)), C2) -> (zext (add nuw X, C1+C2))

This is only possible if C2 is negative and C2 is greater than or equal to negative C1.

llvm-svn: 290927
2017-01-04 02:21:31 +00:00
Matt Arsenault 56ff4839ae InstCombine: Fold fabs on select of constants
llvm-svn: 290913
2017-01-03 22:40:34 +00:00
Sanjay Patel f0d1e77373 [InstCombine] use 'match' to reduce code bloat; NFCI
I wrote this patch before seeing the comment in:
https://reviews.llvm.org/D27114
...that suggests we should actually be canonicalizing the other way.

So just in case we decide this is the right way, we might as well
have a cleaner implementation.

llvm-svn: 290912
2017-01-03 22:25:31 +00:00
Matt Arsenault b264c94963 InstCombine: Add fma with constant transforms
DAGCombine already does these.

llvm-svn: 290860
2017-01-03 04:32:35 +00:00
Matt Arsenault 1cc294c85d InstCombine: Add fma + fabs/fneg transforms
fma (fneg x), (fneg y), z -> fma x, y, z
fma (fabs x), (fabs x), z -> fma x, x, z

llvm-svn: 290859
2017-01-03 04:32:31 +00:00
Sanjay Patel b38ad88e9f [InstCombine] use combineMetadataForCSE instead of copying it; NFCI
llvm-svn: 290844
2017-01-02 23:25:28 +00:00
Craig Topper d00db69227 [InstCombine][AVX-512] Teach InstCombine that llvm.x86.avx512.vcomi.sd and llvm.x86.avx512.vcomi.ss don't use the upper elements of their input.
This was already done for the SSE/SSE2 version of the intrinsics.

llvm-svn: 290776
2016-12-31 00:45:06 +00:00
Craig Topper 991636312b [InstCombine][AVX-512] When turning intrinsics with masking into native IR, don't emit a select if the mask is known to be all ones.
This saves InstCombine the burden of having to optimize the select later.

llvm-svn: 290774
2016-12-30 23:06:28 +00:00
David Majnemer 5ec5f278c9 [InstCombine] Address post-commit feedback
llvm-svn: 290741
2016-12-30 03:36:17 +00:00
David Majnemer a1cfd7c5f8 [InstCombine] More thoroughly canonicalize the position of zexts
We correctly canonicalized (add (sext x), (sext y)) to (sext (add x, y))
where possible.  However, we didn't perform the same canonicalization
for zexts or for muls.

llvm-svn: 290733
2016-12-30 00:28:58 +00:00
Craig Topper 17b5568bc7 [InstCombine] Use getVectorNumElements instead of explicitly casting to VectorType and calling getNumElements. NFC
llvm-svn: 290707
2016-12-29 07:03:18 +00:00
Craig Topper 62f06e241b [InstCombine] Fix typo in comment. NFC
llvm-svn: 290706
2016-12-29 05:38:31 +00:00
Craig Topper 2e18bcfc60 [InstCombine] Use a 32-bits instead of 64-bits for storing the number of elements in VectorType for a ShuffleVector. While there getVectorNumElements to avoid an explicit cast. NFC
llvm-svn: 290705
2016-12-29 04:24:32 +00:00
Craig Topper 1a8a3377cc [InstCombine][X86] If the lowest element of a scalar intrinsic isn't used make sure we add it to the worklist so we can DCE it sooner.
We bypassed the intrinsic and returned the passthru operand, but we should also add the intrinsic to the worklist since its now dead. This can allow DCE to find it sooner and remove it. Similar was done for InsertElement when the inserted element isn't demanded.

llvm-svn: 290704
2016-12-29 03:30:17 +00:00
Craig Topper 28ec3460e4 [InstCombine] Remove a piece of a comment that said that InstCombiner contains pass infrastructure. That hasn't been true since r226618. NFC
llvm-svn: 290648
2016-12-28 03:12:42 +00:00
Michael Kuperstein cd7ad7130f [InstCombine] Canonicalize insert splat sequences into an insert + shuffle
This adds a combine that canonicalizes a chain of inserts which broadcasts
a value into a single insert + a splat shufflevector.

This fixes PR31286.

Differential Revision: https://reviews.llvm.org/D27992

llvm-svn: 290641
2016-12-28 00:18:08 +00:00
Craig Topper 72f2d4e8d6 [InstCombine][X86] Add DemandedElts support for 512-bit PMULDQ/PMULUDQ instructions
PMULDQ/PMULUDQ vXi64 instructions only use the even numbered v2Xi32 input elements which SimplifyDemandedVectorElts should try and use.

This builds on r290554 which added supported for 128 and 256-bit.

llvm-svn: 290582
2016-12-27 05:30:09 +00:00
Craig Topper 7f8540b5e7 [AVX-512][InstCombine] Teach InstCombine to turn masked scalar add/sub/mul/div with rounding intrinsics into normal IR operations if the rounding mode is CUR_DIRECTION.
An earlier commit added support for unmasked scalar operations. At that time isel wouldn't generate an optimal sequence for masked operations, but that has now been fixed.

llvm-svn: 290566
2016-12-27 01:56:30 +00:00
Craig Topper 020b228155 [AVX-512][InstCombine] Teach InstCombine to turn packed add/sub/mul/div with rounding intrinsics into normal IR operations if the rounding mode is CUR_DIRECTION.
llvm-svn: 290559
2016-12-27 00:23:16 +00:00
Simon Pilgrim c9cf7fc7a4 [InstCombine][X86] Add DemandedElts support for PMULDQ/PMULUDQ instructions
PMULDQ/PMULUDQ vXi64 instructions only use the even numbered v2Xi32 input elements which SimplifyDemandedVectorElts should try and use.

Differential Revision: https://reviews.llvm.org/D28119

llvm-svn: 290554
2016-12-26 23:28:17 +00:00
Craig Topper 7b788ada2d [AVX-512][InstCombine] Teach InstCombine to turn scalar add/sub/mul/div with rounding intrinsics into normal IR operations if the rounding mode is CUR_DIRECTION.
Summary:
I only do this for unmasked cases for now because isel is failing to fold the mask. I'll try to fix that soon.

I'll do the same thing for packed add/sub/mul/div in a future patch.

Reviewers: delena, RKSimon, zvi, craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27879

llvm-svn: 290535
2016-12-26 06:33:19 +00:00
Craig Topper e328045711 [AVX-512][InstCombine] Teach InstCombine to converted masked vpermv intrinsics into shufflevector instructions
Summary:
This patch adds support for converting the masked vpermv intrinsics into shufflevector instructions if the indices are constants.

We also need to wrap a select instruction around the shuffle to take care of the masking part. InstCombine will take care of optimizing the select if the mask is constant so I didn't bother checking for that.

Reviewers: zvi, delena, spatel, RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27825

llvm-svn: 290530
2016-12-25 23:58:57 +00:00
David Majnemer b0761a0c1b Revert "[InstCombine] New opportunities for FoldAndOfICmp and FoldXorOfICmp"
This reverts commit r289813, it caused PR31449.

llvm-svn: 290266
2016-12-21 19:21:59 +00:00
George Burgess IV 3f08914e7e [Analysis] Centralize objectsize lowering logic.
We're currently doing nearly the same thing for @llvm.objectsize in
three different places: two of them are missing checks for overflow,
and one of them could subtly break if InstCombine gets much smarter
about removing alloc sites. Seems like a good idea to not do that.

llvm-svn: 290214
2016-12-20 23:46:36 +00:00
Sanjay Patel 5a443ac000 [InstCombine] use commutative matcher for pattern with commutative operators
This is a case that was missed in:
https://reviews.llvm.org/rL290067
...and it would regress if we fix operand complexity (PR28296).

llvm-svn: 290127
2016-12-19 18:35:37 +00:00
Sanjay Patel dd46b52942 [InstCombine] add folds for icmp (umin|umax X, Y), X
This is a follow-up to:
https://reviews.llvm.org/rL289855 (https://reviews.llvm.org/D27531)
https://reviews.llvm.org/rL290111

llvm-svn: 290118
2016-12-19 17:32:37 +00:00
Sanjay Patel 8296c6c96f [InstCombine] add folds for icmp (smax X, Y), X
This is a follow-up to:
https://reviews.llvm.org/rL289855 (D27531)

llvm-svn: 290111
2016-12-19 16:28:53 +00:00
Daniel Jasper aec2fa352f Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Sanjay Patel 2b9d4b4daf [InstCombine] use commutative matchers for patterns with commutative operators
Background/motivation - I was circling back around to:
https://llvm.org/bugs/show_bug.cgi?id=28296

I made a simple patch for that and noticed some regressions, so added test cases for
those with rL281055, and this is hopefully the minimal fix for just those cases.

But as you can see from the surrounding untouched folds, we are missing commuted patterns
all over the place, and of course there are no regression tests to cover any of those cases.

We could sprinkle "m_c_" dust all over this file and catch most of the missing folds, but 
then we still wouldn't have test coverage, and we'd still miss some fraction of commuted 
patterns because they require adjustments to the match order.

I'm aware of the concern about the potential compile-time performance impact of adding 
matches like this (currently being discussed on llvm-dev), but I don't think there's any
evidence yet to suggest that handling commutative pattern matching more thoroughly is not
a worthwhile goal of InstCombine.

Differential Revision: https://reviews.llvm.org/D24419

llvm-svn: 290067
2016-12-18 18:49:48 +00:00
Craig Topper e32b5fd7f9 [InstCombine] Simplify code slightly. NFC
llvm-svn: 290046
2016-12-17 18:10:04 +00:00
Sanjay Patel d640641a61 [InstCombine] add folds for icmp (smin X, Y), X
Min/max canonicalization (r287585) exposes the fact that we're missing combines for min/max patterns. 
This patch won't solve the example that was attached to that thread, so something else still needs fixing.

The line between InstCombine and InstSimplify gets blurry here because sometimes the icmp instruction that
we want to fold to already exists, but sometimes it's the swapped form of what we want.

Corresponding changes for smax/umin/umax to follow.

Differential Revision: https://reviews.llvm.org/D27531

llvm-svn: 289855
2016-12-15 19:13:37 +00:00
Ehsan Amiri 795b0671c5 [InstCombine] New opportunities for FoldAndOfICmp and FoldXorOfICmp
A number of new patterns for simplifying and/xor of icmp:

(icmp ne %x, 0) ^ (icmp ne %y, 0) => icmp ne %x, %y if the following is true:
1- (%x = and %a, %mask) and (%y = and %b, %mask)
2- %mask is a power of 2.

(icmp eq %x, 0) & (icmp ne %y, 0) => icmp ult %x, %y if the following is true:
1- (%x = and %a, %mask1) and (%y = and %b, %mask2)
2- Let %t be the smallest power of 2 where %mask1 & %t != 0. Then for any
   %s that is a power of 2 and %s & %mask2 != 0, we must have %s <= %t.
For example if %mask1 = 24 and %mask2 = 16, setting %s = 16 and %t = 8
violates condition (2) above. So this optimization cannot be applied.

llvm-svn: 289813
2016-12-15 12:25:13 +00:00
Craig Topper ab5f355d8c [AVX-512][InstCombine] Add masked scalar FMA intrinsics to SimplifyDemandedVectorElts.
llvm-svn: 289759
2016-12-15 03:49:45 +00:00
Hal Finkel 3ca4a6bcf1 Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
Hal Finkel cb9f78e1c3 Make processing @llvm.assume more efficient by using operand bundles
There was an efficiency problem with how we processed @llvm.assume in
ValueTracking (and other places). The AssumptionCache tracked all of the
assumptions in a given function. In order to find assumptions relevant to
computing known bits, etc. we searched every assumption in the function. For
ValueTracking, that means that we did O(#assumes * #values) work in InstCombine
and other passes (with a constant factor that can be quite large because we'd
repeat this search at every level of recursion of the analysis).

Several of us discussed this situation at the last developers' meeting, and
this implements the discussed solution: Make the values that an assume might
affect operands of the assume itself. To avoid exposing this detail to
frontends and passes that need not worry about it, I've used the new
operand-bundle feature to add these extra call "operands" in a way that does
not affect the intrinsic's signature. I think this solution is relatively
clean. InstCombine adds these extra operands based on what ValueTracking, LVI,
etc. will need and then those passes need only search the users of the values
under consideration. This should fix the computational-complexity problem.

At this point, no passes depend on the AssumptionCache, and so I'll remove
that as a follow-up change.

Differential Revision: https://reviews.llvm.org/D27259

llvm-svn: 289755
2016-12-15 02:53:42 +00:00
Robert Lougher cfd7198698 [InstCombine] Folding of a compare with RHS const should merge debug locations
If all the operands to a phi node are compares that have a RHS constant,
instcombine will try to pull them through the phi node, combining them into
a single operation. When it does this, the debug location of the new op
should be the merged debug locations of the phi node arguments.

Patch 8 of 8 for D26256.  Folding of a compare that has a RHS constant.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289704
2016-12-14 20:27:22 +00:00
Robert Lougher c9f7354776 [InstCombine] Folding of a binop with RHS const should merge the debug locations
If all the operands to a phi node are a binop with a RHS constant, instcombine
will try to pull them through the phi node, combining them into a single
operation. When it does this, the debug location of the new op should be the
merged debug locations of the phi node arguments.

Patch 7 of 8 for D26256.  Folding of a binop with RHS constant.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289699
2016-12-14 20:07:49 +00:00
Robert Lougher f02d9b8325 [InstCombine] When folding casts through a phi node merge the debug locations
If all the operands to a phi node are a cast, instcombine will try to pull
them through the phi node, combining them into a single cast. When it does
this, the debug location of the new cast should be the merged debug locations
of the phi node arguments.

Patch 6 of 8 for D26256.  Folding of a cast operation.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289693
2016-12-14 19:24:01 +00:00
Robert Lougher 373e36a410 [InstCombine] Folding loads through a phi node should merge the debug locations
If all the operands to a phi node are a load, instcombine will try to pull
them through the phi node, combining them into a single load. When it does
this, the debug location of the new load should be the merged debug locations
of the phi node arguments.

Patch 5 of 8 for D26256.  Folding of a load operation.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289688
2016-12-14 19:02:14 +00:00
Robert Lougher 8fc1e89bbb [InstCombine] When folding GEP through a phi node merge the debug locations
If all the operands to a phi node are getelementptr, instcombine
will try to pull them through the phi node, combining them into a single
operation.  When it does this, the debug location of the new getelementptr
should be the merged debug locations of the phi node arguments.

Patch 4 of 8 for D26256.  Folding of a getelementptr operation.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289684
2016-12-14 18:37:50 +00:00
Robert Lougher 4b0790d488 [InstCombine] Merge debug locations when folding through a phi node
If all the operands to a phi node are of the same operation, instcombine
will try to pull them through the phi node, combining them into a single
operation.  When it does this, the debug location of the operation should
be the merged debug locations of the phi node arguments.

Patch 3 of 8 for D26256.  Folding of a compare operation.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289681
2016-12-14 18:14:57 +00:00
Robert Lougher 2428a4050f [InstCombine] Merge debug locations when folding through a phi node
If all the operands to a phi node are of the same operation, instcombine
will try to pull them through the phi node, combining them into a single
operation.  When it does this, the debug location of the operation should
be the merged debug locations of the phi node arguments.

Patch 2 of 8 for D26256.  Folding of a binary operation.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289679
2016-12-14 17:49:19 +00:00
Stephan Bergmann 17c7f70362 Replace APFloatBase static fltSemantics data members with getter functions
At least the plugin used by the LibreOffice build
(<https://wiki.documentfoundation.org/Development/Clang_plugins>) indirectly
uses those members (through inline functions in LLVM/Clang include files in turn
using them), but they are not exported by utils/extract_symbols.py on Windows,
and accessing data across DLL/EXE boundaries on Windows is generally
problematic.

Differential Revision: https://reviews.llvm.org/D26671

llvm-svn: 289647
2016-12-14 11:57:17 +00:00
Craig Topper aeaa52cc11 [X86][InstCombine] Handle demanded elements for operand of AVX-512 scalar floating point to integer conversion intrinsics.
llvm-svn: 289639
2016-12-14 07:46:12 +00:00
Craig Topper 268b3abe6d [X86][InstCombine] Teach SimplifyDemandedVectorElts to handle masked scalar add/sub/mul/div/max/min intrinsics better.
Now we can remove these intrinsics if element 0 isn't used. Also fix undef element tracking.

llvm-svn: 289636
2016-12-14 06:06:58 +00:00
Craig Topper dfd268d76b [X86][InstCombine] Handle scalar fmadd intrinsics correctly in SimplifyDemandedVectorElts.
Now we pass a modified version of DemandedElts to each operand and we calculate undef elts correctly.

llvm-svn: 289632
2016-12-14 05:43:05 +00:00
Craig Topper eb6a20e79e [X86][InstCombine] Teach SimplifyDemandedVectorElts to handle scalar round intrinsics more correctly.
Now we only pass bit 0 of the DemandedElts to optimize operand 1 as we recurse since the upper bits are unused. Similarly we clear bit 0 for optimizing operand 0.

Also calculate UndefElts correctly.

Simplify InstCombineCalls for these instrinics to just call SimplifyDemandedVectorElts for the call instrution to reuse this support.

llvm-svn: 289629
2016-12-14 03:17:30 +00:00
Craig Topper a0372dec26 [X86][InstCombine] Teach SimplifyDemandedVectorElts to handle scalar min/max/cmp intrinsics more correctly.
Now we only pass bit 0 of the DemandedElts to optimize operand 1 as we recurse since the upper bits are unused.

Also calculate UndefElts correctly.

Simplify InstCombineCalls for these instrinics to just call SimplifyDemandedVectorElts for the call instrution to reuse this support.

llvm-svn: 289628
2016-12-14 03:17:27 +00:00
Craig Topper ac75bca1eb [X86][InstCombine] Fix SimplifyDemandedVectorElts to handle frcz scalar intrinsics correctly.
Only the lower bits of the input element are used. And only the lower element can be undef since the upper bits are zeroed.

Have InstCombineCalls call SimplifyDemandedVectorElts for these intrinsics to reuse this support.

llvm-svn: 289523
2016-12-13 07:45:45 +00:00
Sanjay Patel e730ce87a5 [InstCombine] fix bug when offsetting case values of a switch (PR31260)
We could truncate the condition and then try to fold the add into the
original condition value causing wrong case constants to be used.

Move the offset transform ahead of the truncate transform and return
after each transform, so there's no chance of getting confused values.

Fix for:
https://llvm.org/bugs/show_bug.cgi?id=31260

llvm-svn: 289442
2016-12-12 16:13:52 +00:00
Sanjay Patel 87e2f677d7 [InstCombine] clean up range-for-loops in visitSwitchInst(); NFCI
llvm-svn: 289439
2016-12-12 15:52:56 +00:00
Craig Topper 7fc6d34ed1 [InstCombine][XOP] The instructions for the scalar frcz intrinsics are defined to put 0 in the upper bits, not pass bits through like other intrinsics. So we should return a zero vector instead.
llvm-svn: 289411
2016-12-11 22:32:38 +00:00
Craig Topper 23ebd9564f [X86][InstCombine] Add support for scalar FMA intrinsics to SimplifyDemandedVectorElts.
This teaches SimplifyDemandedElts that the FMA can be removed if the lower element isn't used. It also teaches it that if upper elements of the first operand aren't used then we can simplify them.

llvm-svn: 289377
2016-12-11 08:54:52 +00:00
Craig Topper 61b280e7b0 [X86][InstCombine] Teach InstCombineCalls to simplify demanded elements for scalar FMA intrinsics.
These intrinsics don't read the upper bits of their second and third inputs so we can try to simplify them.

llvm-svn: 289372
2016-12-11 07:42:06 +00:00
Craig Topper d96395365a [AVX-512][InstCombine] Teach InstCombineCalls how to simplify demanded for scalar cmp intrinsics with masking and rounding.
These intrinsics don't read the upper elements of their first and second input. These are slightly different the the SSE version which does use the upper bits of its first element as passthru bits since the result goes to an XMM register. For AVX-512 the result goes to a mask register instead.

llvm-svn: 289371
2016-12-11 07:42:04 +00:00
Craig Topper 790d0fa569 [AVX-512][InstCombine] Teach InstCombineCalls how to simplify demanded elements for scalar add,div,mul,sub,max,min intrinsics with masking and rounding.
These intrinsics don't read the upper bits of their second input. And the third input is the passthru for masking and that only uses the lower element as well.

llvm-svn: 289370
2016-12-11 07:42:01 +00:00
Craig Topper 58917f3508 [AVX-512][InstCombine] Add 512-bit vpermilvar intrinsics to InstCombineCalls to match 128 and 256-bit.
llvm-svn: 289354
2016-12-11 01:59:36 +00:00
Craig Topper 9a63d7ade5 [X86][InstCombine] Teach InstCombineCalls to turn pshufb intrinsic into a shufflevector if the indices are constant.
llvm-svn: 289348
2016-12-11 00:23:50 +00:00
Sanjay Patel 4c48bbe94d [InstCombine] add helper for shift-by-shift folds; NFCI
These are currently limited to integer types, but we should
be able to extend to splat vectors and possibly general vectors.

llvm-svn: 289343
2016-12-10 22:16:29 +00:00
Sanjay Patel b7f8cb698c [InstCombine] change select type to eliminate bitcasts
This solves a secondary problem seen in PR6137:
https://llvm.org/bugs/show_bug.cgi?id=6137#c6

This is similar to the bitwise logic op fold added with:
https://reviews.llvm.org/rL287707

And like that patch, I'm artificially restricting the
transform from vector <-> scalar types until we're sure
that the backend can handle that. 

llvm-svn: 288584
2016-12-03 15:25:16 +00:00
Peter Collingbourne ab85225be4 IR: Change the gep_type_iterator API to avoid always exposing the "current" type.
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.

Differential Revision: https://reviews.llvm.org/D26594

llvm-svn: 288458
2016-12-02 02:24:42 +00:00
Philip Reames 89e92d21b4 [PR29121] Don't fold if it would produce atomic vector loads or stores
The instcombine code which folds loads and stores into their use types can trip up if the use is a bitcast to a type which we can't directly load or store in the IR. In principle, such types shouldn't exist, but in practice they do today. This is a workaround to avoid a bug while we work towards the long term goal.

Differential Revision: https://reviews.llvm.org/D24365

llvm-svn: 288415
2016-12-01 20:17:06 +00:00
Sanjay Patel aa8b28e509 [InstCombine] allow more narrowing transforms for logic ops
We had a limited version of this for scalar 'and'; this expands
the transform to 'or' and 'xor' and allows vectors types too.

llvm-svn: 288273
2016-11-30 20:48:54 +00:00
Sanjay Patel 8ca30ab0c5 [InstSimplify] allow integer vector types to use computeKnownBits
Note that the non-splat lshr+lshr test folded, but that does not
work in general. Something is missing or wrong in computeKnownBits
as the non-splat shl+shl test still shows.

llvm-svn: 288005
2016-11-27 21:07:28 +00:00
Sanjay Patel 8bd69b7ed9 [InstCombine] don't drop metadata in FoldOpIntoSelect()
llvm-svn: 287980
2016-11-26 15:23:20 +00:00
Sanjay Patel 91e73a7bfa add optional param to copy metadata when creating selects; NFC
There are other spots where we can use this; we're currently dropping 
metadata in some places, and there are proposed changes where we will
want to propagate metadata.

IRBuilder's CreateSelect() already has a parameter like this, so this
change makes the regular 'Create' API line up with that.

llvm-svn: 287976
2016-11-26 15:01:59 +00:00
David Majnemer d5648c7a7d Replace some callers of setTailCall with setTailCallKind
We were a little sloppy with adding tailcall markers.  Be more
consistent by using setTailCallKind instead of setTailCall.

llvm-svn: 287955
2016-11-25 22:35:09 +00:00
Sanjay Patel 1e6ca44a8e add and use isBitwiseLogicOp() helper function; NFCI
llvm-svn: 287712
2016-11-22 22:54:36 +00:00
Sanjay Patel e359eaaf70 [InstCombine] change bitwise logic type to eliminate bitcasts
In PR27925:
https://llvm.org/bugs/show_bug.cgi?id=27925

...we proposed adding this fold to eliminate a bitcast. In D20774, there was 
some concern about changing the type of a bitwise op as well as creating 
bitcasts that might not be free for a target. However, if we're strictly 
eliminating an instruction (by limiting this to one-use ops), then we should 
be able to do this in InstCombine.

But we're cautiously restricting the transform for now to vector types to
avoid possible backend problems. A transform to make sure the logic op is
legal for the target should be added to reverse this transform and improve
codegen.

Differential Revision: https://reviews.llvm.org/D26641

llvm-svn: 287707
2016-11-22 22:05:48 +00:00
Sanjay Patel 3b0bafee63 [InstCombine] canonicalize min/max constant to select's false value
This is a first step towards canonicalization and improved folding/codegen
for integer min/max as discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/106868.html

Here, we're just matching the simplest min/max patterns and adjusting the
icmp predicate while swapping the select operands.

I've included FIXME tests in test/Transforms/InstCombine/select_meta.ll
so it's easier to see how this might be extended (corresponds to the TODO
comment in the code). That's also why I'm using matchSelectPattern()
rather than a simpler check; once the backend is patched, we can just 
remove some of the restrictions to allow the obfuscated min/max patterns
in the FIXME tests to be matched.

Differential Revision: https://reviews.llvm.org/D26525

llvm-svn: 287585
2016-11-21 22:04:14 +00:00
Sanjay Patel c89911ba02 fix formatting; NFC
llvm-svn: 287582
2016-11-21 21:48:36 +00:00
Simon Pilgrim 7d18a70dac Fix spelling mistakes in Transforms comments. NFC.
Identified by Pedro Giffuni in PR27636.

llvm-svn: 287488
2016-11-20 13:19:49 +00:00
Craig Topper 1de753f7f5 [InstCombine][AVX-512] Teach InstCombineCalls how to handle the intrinsics for variable shift with 16-bit elements.
This is a straightforward extension of the existing support for 32/64-bit element types. Just needed to add the additional instrinsics to the switches.

llvm-svn: 287316
2016-11-18 06:04:33 +00:00
Chris Bieneman 05c279fc4b [CMake] NFC. Updating CMake dependency specifications
This patch updates a bunch of places where add_dependencies was being explicitly called to add dependencies on intrinsics_gen to instead use the DEPENDS named parameter. This cleanup is needed for a patch I'm working on to add a dependency debugging mode to the build system.

llvm-svn: 287206
2016-11-17 04:36:50 +00:00
Sanjay Patel 80baf69cb5 [InstCombine] replace unreachable with assert and remove unreachable code; NFCI
llvm-svn: 287147
2016-11-16 20:40:02 +00:00
Sanjay Patel 1b9560ffd6 [InstCombine] fix formatting and add FIXMEs to foldOperationIntoSelectOperand(); NFC
llvm-svn: 287145
2016-11-16 20:18:34 +00:00
Craig Topper 6910fa0ef4 [X86] Remove the scalar intrinsics for fadd/fsub/fdiv/fmul
Summary: These intrinsics have been unused for clang for a while. This patch removes them. We auto upgrade them to extractelements, a scalar operation and then an insertelement. This matches the sequence used by clangs intrinsic file.

Reviewers: zvi, delena, RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26660

llvm-svn: 287083
2016-11-16 05:24:10 +00:00
Craig Topper b4173a5a70 [InstCombine][AVX-512] Teach InstCombineCalls to handle the new unmasked AVX-512 variable shift intrinsics.
llvm-svn: 286755
2016-11-13 07:26:19 +00:00
Craig Topper 8b831cbb2a [InstCombine][AVX-512] Expand vector shift handling to work on the AVX-512 shift by immediate and shift by single value.
This does not include support for the AVX-512 variable shifts. That will be coming in a future patch.

llvm-svn: 286739
2016-11-13 01:51:55 +00:00
Sanjay Patel 84ae943f0d [InstCombine] use dyn_cast rather isa+cast; NFC
Follow-up to r286664 cleanup as suggested by Eli. Thanks!

llvm-svn: 286671
2016-11-11 23:20:01 +00:00
Sanjay Patel cb2199b2f3 [InstCombine] clean up foldSelectOpOp(); NFC
llvm-svn: 286664
2016-11-11 23:01:20 +00:00