Commit Graph

9077 Commits

Author SHA1 Message Date
Sanjay Patel c71adc8040 [Intrinsics] define funnel shift IR intrinsics + DAG builder support
As discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123292.html
http://lists.llvm.org/pipermail/llvm-dev/2018-July/124400.html

We want to add rotate intrinsics because the IR expansion of that pattern is 4+ instructions, 
and we can lose pieces of the pattern before it gets to the backend. Generalizing the operation 
by allowing 2 different input values (plus the 3rd shift/rotate amount) gives us a "funnel shift" 
operation which may also be a single hardware instruction.

Initially, I thought we needed to define new DAG nodes for these ops, and I spent time working 
on that (much larger patch), but then I concluded that we don't need it. At least as a first 
step, we have all of the backend support necessary to match these ops...because it was required. 
And shepherding these through the IR optimizer is the primary concern, so the IR intrinsics are 
likely all that we'll ever need.

There was also a question about converting the intrinsics to the existing ROTL/ROTR DAG nodes
(along with improving the oversized shift documentation). Again, I don't think that's strictly 
necessary (as the test results here prove). That can be an efficiency improvement as a small 
follow-up patch.

So all we're left with is documentation, definition of the IR intrinsics, and DAG builder support. 

Differential Revision: https://reviews.llvm.org/D49242

llvm-svn: 337221
2018-07-16 22:59:31 +00:00
Fangrui Song cb0bab86b3 [CodeGen] Fix inconsistent declaration parameter name
llvm-svn: 337200
2018-07-16 18:51:40 +00:00
Roman Lebedev de506632aa [X86][AArch64][DAGCombine] Unfold 'check for [no] signed truncation' pattern
Summary:

[[ https://bugs.llvm.org/show_bug.cgi?id=38149 | PR38149 ]]

As discussed in https://reviews.llvm.org/D49179#1158957 and later,
the IR for 'check for [no] signed truncation' pattern can be improved:
https://rise4fun.com/Alive/gBf
^ that pattern will be produced by Implicit Integer Truncation sanitizer,
https://reviews.llvm.org/D48958 https://bugs.llvm.org/show_bug.cgi?id=21530
in signed case, therefore it is probably a good idea to improve it.

But the IR-optimal patter does not lower efficiently, so we want to undo it..

This handles the simple pattern.
There is a second pattern with predicate and constants inverted.

NOTE: we do not check uses here. we always do the transform.

Reviewers: spatel, craig.topper, RKSimon, javed.absar

Reviewed By: spatel

Subscribers: kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D49266

llvm-svn: 337166
2018-07-16 12:44:10 +00:00
Daniel Cederman c3d8002c2e Avoid losing Hi part when expanding VAARG nodes on big endian machines
Summary:
If the high part of the load is not used the offset to the next element
will not be set correctly.

For example, on Sparc V8, the following code will read val2 from offset 4
instead of 8.

```
int val = __builtin_va_arg(va, long long);
int val2 = __builtin_va_arg(va, int);
```

Reviewers: jyknight

Reviewed By: jyknight

Subscribers: fedor.sergeev, jrtc27, llvm-commits

Differential Revision: https://reviews.llvm.org/D48595

llvm-svn: 337161
2018-07-16 12:14:17 +00:00
Sanjay Patel 79a423cfa2 [DAGCombiner] fix typo in comment; NFC
llvm-svn: 337132
2018-07-15 17:09:35 +00:00
Sanjay Patel a41c886c55 [DAGCombiner] extend(ifpositive(X)) -> shift-right (not X)
This is almost the same as an existing IR canonicalization in instcombine, 
so I'm assuming this is a good early generic DAG combine too.

The motivation comes from reduced bit-hacking for select-of-constants in IR 
after rL331486. We want to restore that functionality in the DAG as noted in
the commit comments for that change and the llvm-dev discussion here:
http://lists.llvm.org/pipermail/llvm-dev/2018-July/124433.html

The PPC and AArch tests show that those targets are already doing something 
similar. x86 will be neutral in the minimal case and generally better when 
this pattern is extended with other ops as shown in the signbit-shift.ll tests.

Note the asymmetry: we don't include the (extend (ifneg X)) transform because 
it already exists in SimplifySelectCC(), and that is verified in the later 
unchanged tests in the signbit-shift.ll files. Without the 'not' op, the 
general transform to use a shift is always a win because that's a single 
instruction.

Alive proofs:
https://rise4fun.com/Alive/ysli

Name: if pos, get -1
  %c = icmp sgt i16 %x, -1
  %r = sext i1 %c to i16
  =>
  %n = xor i16 %x, -1
  %r = ashr i16 %n, 15

Name: if pos, get 1
  %c = icmp sgt i16 %x, -1
  %r = zext i1 %c to i16
  =>
  %n = xor i16 %x, -1
  %r = lshr i16 %n, 15

Differential Revision: https://reviews.llvm.org/D48970

llvm-svn: 337130
2018-07-15 16:27:07 +00:00
Matthias Braun 90ad6835dd CodeGen: Remove pipeline dependencies on StackProtector; NFC
This re-applies r336929 with a fix to accomodate for the Mips target
scheduling multiple SelectionDAG instances into the pass pipeline.

PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.

PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.

This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.

Patch by Stephen Crane <sjc@immunant.com>

Differential Revision: https://reviews.llvm.org/D49256

llvm-svn: 336964
2018-07-13 00:08:38 +00:00
Matthias Braun f03f32d478 Revert "(HEAD -> master, origin/master, arcpatch-D37582) CodeGen: Remove pipeline dependencies on StackProtector; NFC"
This was triggering pass scheduling failures.

This reverts commit r336929.

llvm-svn: 336934
2018-07-12 19:27:01 +00:00
Matthias Braun 9436570cbd CodeGen: Remove pipeline dependencies on StackProtector; NFC
PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.

PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.

This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.

Patch by Stephen Crane <sjc@immunant.com>

Differential Revision: https://reviews.llvm.org/D49256

llvm-svn: 336929
2018-07-12 18:33:32 +00:00
Eli Friedman 0319c28459 [CodeGen] Emit more precise AssertZext/AssertSext nodes.
This is marginally helpful for removing redundant extensions, and the
code is easier to read, so it seems like an all-around win. In the new
test i8-phi-ext.ll, we used to emit an AssertSext i8; now we emit an
AssertZext i2, which allows the extension of the return value to be
eliminated.

Differential Revision: https://reviews.llvm.org/D49004

llvm-svn: 336868
2018-07-11 23:26:35 +00:00
Diogo N. Sampaio b0d85ef975 [NFC][InstCombine] Converts isLegalNarrowLoad into isLegalNarrowLdSt
Reuse this function as to test correctness and profitability of
reducing width of either load or store operations.

Reviewsers: samparker

Differential Revision: https://reviews.llvm.org/D48624

llvm-svn: 336800
2018-07-11 12:59:42 +00:00
Simon Pilgrim 075b04a55f [SelectionDAG] Add constant buildvector support to isKnownNeverZero
This allows us to use SelectionDAG::isKnownNeverZero in DAGCombiner::visitREM (visitSDIVLike/visitUDIVLike handle the checking for constants).

llvm-svn: 336779
2018-07-11 09:56:41 +00:00
Simon Pilgrim df9d59771b [DAGCombiner] Support non-uniform X%C -> X-(X/C)*C folds
First stage in PR38057 - support non-uniform constant vectors in the combine to reuse the division-by-constant logic.

We can definitely do better for srem pow2 remainders (and avoid that extra multiply....) but this at least helps keep everything on the vector unit.

Differential Revision: https://reviews.llvm.org/D48975

llvm-svn: 336774
2018-07-11 09:22:42 +00:00
Simon Pilgrim 97cf111689 [DAGCombiner] Add (urem X, -1) -> select(X == -1, 0, x) fold
llvm-svn: 336773
2018-07-11 09:14:37 +00:00
Simon Pilgrim 4cb4609392 [DAGCombiner] Add special case fast paths for udiv x,1 and udiv x,-1
udiv x,-1 was going down the (slow) BuildUDIV route resulting in unnecessary shifts.

llvm-svn: 336701
2018-07-10 16:33:07 +00:00
Simon Pilgrim 641097d561 [DAGCombiner] visitREM - call visitSDIVLike/visitUDIVLike directly to avoid recursive combining.
As suggested by @efriedma on D48975 use the visitSDIVLike/visitUDIVLike functions introduced at rL336656.

llvm-svn: 336664
2018-07-10 13:18:16 +00:00
Simon Pilgrim ce5c19b623 [DAGCombiner] Split SDIV/UDIV optimization expansions from the rest of the combines. NFCI.
As suggested by @efriedma on D48975, this patch separates the BuildDiv/Pow2 style optimizations from the rest of the visitSDIV/visitUDIV to make it easier to reuse the combines and will allow us to avoid some rather nasty node recursive combining in visitREM.

llvm-svn: 336656
2018-07-10 11:38:00 +00:00
Roman Lebedev 5ccae1750b [X86][TLI] DAGCombine: Unfold variable bit-clearing mask to two shifts.
Summary:
This adds a reverse transform for the instcombine canonicalizations
that were added in D47980, D47981.

As discussed later, that was worse at least for the code size,
and potentially for the performance, too.

https://rise4fun.com/Alive/Zmpl

Reviewers: craig.topper, RKSimon, spatel

Reviewed By: spatel

Subscribers: reames, llvm-commits

Differential Revision: https://reviews.llvm.org/D48768

llvm-svn: 336585
2018-07-09 19:06:42 +00:00
Craig Topper e3b0c7e5bd [SelectionDAG] Add VT consistency checks to the creation of ISD::FMA.
This is similar to what is done for binops. I don't know if this would have helped us catch the bug fixed in r336566 earlier or not, but I figured it couldn't hurt.

llvm-svn: 336576
2018-07-09 18:23:55 +00:00
Simon Pilgrim 23f9eddabe [SelectionDAG] Split float and integer isKnownNeverZero tests
Splits off isKnownNeverZeroFloat to handle +/- 0 float cases.

This will make it easier to be more aggressive with the integer isKnownNeverZero tests (similar to ValueTracking), use computeKnownBits etc.

Differential Revision: https://reviews.llvm.org/D48969

llvm-svn: 336492
2018-07-07 18:17:14 +00:00
Simon Pilgrim 0a36daa5a2 Use const APInt& to avoid extra copy. NFCI.
As discussed on D48825.

llvm-svn: 336491
2018-07-07 17:33:48 +00:00
Simon Pilgrim c1d1944053 [DAGCombiner] Add EXTRACT_SUBVECTOR to SimplifyDemandedVectorElts
As discussed on PR37989, this patch adds EXTRACT_SUBVECTOR handling to TargetLowering::SimplifyDemandedVectorElts and calls it from DAGCombiner::visitEXTRACT_SUBVECTOR.

Differential Revision: https://reviews.llvm.org/D48825

llvm-svn: 336490
2018-07-07 17:30:06 +00:00
Nico Weber 038dbf3c24 Revert 336426 (and follow-ups 428, 440), it very likely caused PR38084.
llvm-svn: 336453
2018-07-06 17:37:24 +00:00
Diogo N. Sampaio 17be994942 Added missing semicolon
llvm-svn: 336428
2018-07-06 10:09:04 +00:00
Diogo N. Sampaio 742bf1a255 [SelectionDAG] https://reviews.llvm.org/D48278
D48278

Allow to reduce redundant shift masks.
For example:
x1 = x & 0xAB00
x2 = (x >> 8) & 0xAB

can be reduced to:
x1 = x & 0xAB00
x2 = x1 >> 8
It only allows folding when the masks and shift values are constants.

llvm-svn: 336426
2018-07-06 09:42:25 +00:00
Diogo N. Sampaio 734cfd11fe Testing commit permision
llvm-svn: 336384
2018-07-05 18:49:32 +00:00
Simon Pilgrim 74cc4cfa94 [DAGCombiner] visitSDIV - Permit MIN_SIGNED_VALUE in pow2 vector codegen
Now that D45806 has landed, we can re-enable support for MIN_SIGNED_VALUE in the sdiv by pow2-constant code

llvm-svn: 336198
2018-07-03 14:11:32 +00:00
Piotr Padlewski 5b3db45e8f Implement strip.invariant.group
Summary:
This patch introduce new intrinsic -
strip.invariant.group that was described in the
RFC: Devirtualization v2

Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar

Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits

Differential Revision: https://reviews.llvm.org/D47103

Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 336073
2018-07-02 04:49:30 +00:00
Simon Pilgrim fae337704e [DAGCombiner] Handle correctly non-splat power of 2 -1 divisor (PR37119)
The combine added in commit 329525 overlooked the case where one, but not all, of the divisor elements is -1, -1 is the only power of two value for which the sdiv expansion recipe breaks.

Thanks to @zvi for the original patch.

Differential Revision: https://reviews.llvm.org/D45806

llvm-svn: 336048
2018-06-30 12:22:55 +00:00
Simon Pilgrim 9c70d48cb2 [DAGCombiner] Ensure we use the correct CC result type in visitSDIV (REAPPLIED)
We could get away with it for constant folded cases, but not for rL335719.

Thanks to Krzysztof Parzyszek for noticing.

Reapply original commit rL335821 which was reverted at rL335871 due to a WebAssembly bug that was fixed at rL335884.

llvm-svn: 335886
2018-06-28 17:33:41 +00:00
Matthias Braun da5e7e11d1 SelectionDAGBuilder, mach-o: Skip trap after noreturn call (for Mach-O)
Add NoTrapAfterNoreturn target option which skips emission of traps
behind noreturn calls even if TrapUnreachable is enabled.

Enable the feature on Mach-O to save code size; Comments suggest it is
not possible to enable it for the other users of TrapUnreachable.

rdar://41530228

DifferentialRevision: https://reviews.llvm.org/D48674
llvm-svn: 335877
2018-06-28 17:00:45 +00:00
Haojian Wu 2103990e63 Revert "[DAGCombiner] Ensure we use the correct CC result type in visitSDIV"
This reverts commit r335821.

This crashes the webassembly test, run "ninja check-llvm-codegen-webassembly" to reproduce.

llvm-svn: 335871
2018-06-28 16:25:57 +00:00
Simon Pilgrim abebe4c746 [DAGCombiner] Ensure we use the correct CC result type in visitSDIV
We could get away with it for constant folded cases, but not for rL335719.

Thanks to Krzysztof Parzyszek for noticing.

llvm-svn: 335821
2018-06-28 09:54:28 +00:00
Simon Pilgrim 49cb65bb7b [DAGCombiner] Remove unused variable. NFCI.
Noticed in D45806 review.

llvm-svn: 335817
2018-06-28 09:29:08 +00:00
Nirav Dave 7c57ae57a8 [DAGCombine] Disable TokenFactor simplifications when optnone.
llvm-svn: 335773
2018-06-27 19:41:25 +00:00
Sanjay Patel d052de856d [DAGCombiner] restrict (float)((int) f) --> ftrunc with no-signed-zeros
As noted in the D44909 review, the transform from (fptosi+sitofp) to ftrunc 
can produce -0.0 where the original code does not:

#include <stdio.h>
  
int main(int argc) {
  float x;
  x = -0.8 * argc;
  printf("%f\n", (float)((int)x));
  return 0;
}

$ clang -O0 -mavx fp.c ; ./a.out 
0.000000
$ clang -O1 -mavx fp.c ; ./a.out 
-0.000000

Ideally, we'd use IR/node flags to predicate the transform, but the IR parser 
doesn't currently allow fast-math-flags on the cast instructions. So for now, 
just use the function attribute that corresponds to clang's "-fno-signed-zeros" 
option.

Differential Revision: https://reviews.llvm.org/D48085

llvm-svn: 335761
2018-06-27 18:16:40 +00:00
Simon Pilgrim d3e583a52d [DAGCombiner] visitSDIV - add special case handling for (sdiv X, 1) -> X in pow2 expansion
For divisor = 1, perform a select of X - reduces scalarisation of simple SDIVs

llvm-svn: 335727
2018-06-27 12:45:31 +00:00
Simon Pilgrim e835f662fa [DAGCombiner] visitSDIV - simplify pow2 handling. NFCI.
Use the builtin constant folding of getNode() etc. instead of doing it manually.

llvm-svn: 335720
2018-06-27 10:51:55 +00:00
Simon Pilgrim dfbcc66adc [DAGCombiner] Fold SDIV(%X, MIN_SIGNED) -> SELECT(%X == MIN_SIGNED, 1, 0)
Fixes PR37569.

llvm-svn: 335719
2018-06-27 10:21:06 +00:00
Simon Pilgrim 0a566bc0ae [DAGCombiner] Don't accept signbit sdiv divisors in sdiv-by-pow2 vector expansion (PR37569)
llvm-svn: 335717
2018-06-27 09:41:22 +00:00
Sanjay Patel fb9c440ba5 [DAGCombiner] use isBitwiseNot to simplify code; NFC
llvm-svn: 335652
2018-06-26 19:46:56 +00:00
Simon Pilgrim 7f55af37f4 [DAGCombiner] Don't accept -1 sdiv divisors in sdiv-by-pow2 vector expansion (PR37119)
Temporary fix until I've managed to get D45806 updated - both +1 and -1 special cases need to be properly supported.

llvm-svn: 335637
2018-06-26 17:46:51 +00:00
Simon Pilgrim 133b1cdf08 [DAGCombiner] Pull out VT bitwidth in visitSDIV. NFCI.
llvm-svn: 335617
2018-06-26 15:39:16 +00:00
Vedant Kumar b725c69f12 [SelectionDAG] Remove debug locations from ConstantSD(FP)Nodes
This removes debug locations from ConstantSDNode and ConstantSDFPNode.

When this kind of node is materialized we no longer create a line table
entry which jumps back to the constant's first point of use. This makes
single-stepping behavior smoother, and it matches the model used by IR,
where Constants have no locations. See this thread for more context:

  http://lists.llvm.org/pipermail/llvm-dev/2018-June/124164.html

I'd like to handle constant BuildVectorSDNodes and to try to eliminate
passing SDLocs to SelectionDAG::getConstant*() in follow-up commits.

Differential Revision: https://reviews.llvm.org/D48468

llvm-svn: 335497
2018-06-25 17:06:18 +00:00
Simon Pilgrim 5b6b500687 Fix -Wparentheses gcc warning. NFCI.
llvm-svn: 335451
2018-06-25 11:19:05 +00:00
Sanjay Patel 962ee178fa [DAGCombiner] eliminate setcc bool math when input is low-bit of some value
This patch has the same motivating example as D48466:
define void @foo(i64 %x, i32 %c.0282.in, i32 %d.0280, i32* %ptr0, i32* %ptr1) {
    %c.0282 = and i32 %c.0282.in, 268435455
    %a16 = lshr i64 32508, %x
    %a17 = and i64 %a16, 1
    %tobool = icmp eq i64 %a17, 0
    %. = select i1 %tobool, i32 1, i32 2
    %.286 = select i1 %tobool, i32 27, i32 26
    %shr97 = lshr i32 %c.0282, %.
    %shl98 = shl i32 %c.0282.in, %.286
    %or99 = or i32 %shr97, %shl98
    %shr100 = lshr i32 %d.0280, %.
    %shl101 = shl i32 %d.0280, %.286
    %or102 = or i32 %shr100, %shl101
    store i32 %or99, i32* %ptr0
    store i32 %or102, i32* %ptr1
    ret void
}

...but I'm trying to kill the setcc bool math sooner rather than later.

By matching a larger pattern that includes both the low-bit mask and the trailing add/sub, 
we can create a universally good fold because we always eliminate the condition code 
intermediate value.

Here are Alive proofs for these (currently instcombine folds the 'add' variants, but 
misses the 'sub' patterns):
https://rise4fun.com/Alive/Gsyp

Name: sub of zext cmp mask
  %a = and i8 %x, 1
  %c = icmp eq i8 %a, 0
  %z = zext i1 %c to i32
  %r = sub i32 C1, %z
  =>
  %optional_cast = zext i8 %a to i32
  %r = add i32 %optional_cast, C1-1

Name: add of zext cmp mask
  %a = and i32 %x, 1
  %c = icmp eq i32 %a, 0
  %z = zext i1 %c to i8
  %r = add i8 %z, C1
  =>
  %optional_cast = trunc i32 %a to i8
  %r = sub i8 C1+1, %optional_cast

All of the tests look like improvements or neutral to me. But it is possible that x86 
test+set+bitop is better than what we now show here. I suspect we could do better by 
adding another fold for the 'sub' variants.

We start with select-of-constant in IR in the larger motivating test, so that's why I 
included tests with selects. Proofs for those variants:
https://rise4fun.com/Alive/Bx1

Name: true const is bigger
Pre: C2 == (C1 + 1)
  %a = and i8 %x, 1
  %c = icmp eq i8 %a, 0
  %r = select i1 %c, i64 C2, i64 C1
  =>
  %z = zext i8 %a to i64
  %r = sub i64 C2, %z

Name: false const is bigger
Pre: C2 == (C1 + 1)
  %a = and i8 %x, 1
  %c = icmp eq i8 %a, 0
  %r = select i1 %c, i64 C1, i64 C2
  =>
  %z = zext i8 %a to i64
  %r = add i64 C1, %z

Differential Revision: https://reviews.llvm.org/D48466

llvm-svn: 335433
2018-06-24 14:37:30 +00:00
Stanislav Mekhanoshin 22ee191c3e DAG combine "and|or (select c, -1, 0), x" -> "select c, x, 0|-1"
Allowed folding for "and/or" binops with non-constant operand if
arguments of select are 0/-1 values.

Normally this code with "and" opcode does not get to a DAG combiner
and simplified yet in the InstCombine. However AMDGPU produces it
during lowering and InstCombine has no chance to optimize it out.

In turn the same pattern with "or" opcode can reach DAG.

Differential Revision: https://reviews.llvm.org/D48301

llvm-svn: 335250
2018-06-21 16:02:05 +00:00
Mikael Holmen 42f7bc96dd [DebugInfo] Make sure all DBG_VALUEs' reguse operands have IsDebug property
Summary:
In some cases, these operands lacked the IsDebug property, which is meant to signal that
they should not affect codegen. This patch adds a check for this property in the
MachineVerifier and adds it where it was missing.

This includes refactorings to use MachineInstrBuilder construction functions instead of
manually setting up the intrinsic everywhere.

Patch by: JesperAntonsson

Reviewers: aprantl, rnk, echristo, javed.absar

Reviewed By: aprantl

Subscribers: qcolombet, sdardis, nemanjai, JDevlieghere, atanasyan, llvm-commits

Differential Revision: https://reviews.llvm.org/D48319

llvm-svn: 335214
2018-06-21 10:03:34 +00:00
David Green a465188500 [DAGCombine] Fix alignment for offset loads/stores
The alignment parameter to getExtLoad is treated as a base alignment,
not the alignment of the load (base + offset). When we infer a better
alignment for a Ptr we need to ensure that it applies to the base to
prevent the alignment on the load from being wrong.

This fixes a bug where the alignment could then be used to incorrectly
prove noalias between a load and a store, leading to a miscompile.

Differential Revision: https://reviews.llvm.org/D48029

llvm-svn: 335210
2018-06-21 08:30:07 +00:00
Stanislav Mekhanoshin 20279dc025 Allow binop C1, (select cc, CF, CT) -> select folding
Previously this folding was done only if select is a first operand.
However, for non-commutative operations constant may go before
select.

Differential Revision: https://reviews.llvm.org/D48223

llvm-svn: 335167
2018-06-20 20:24:20 +00:00
Bjorn Pettersson 7bf676662a [DAG] Don't map a TableId to itself in the ReplacedValues map
Summary:
Found some regressions (infinite loop in DAGTypeLegalizer::RemapId)
after r334880. This patch makes sure that we do map a TableId to
itself.

Reviewers: niravd

Reviewed By: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D48364

llvm-svn: 335141
2018-06-20 16:06:09 +00:00
Nirav Dave cd558887d3 [DAG] Fix and-mask folding when narrowing loads.
Summary:
Check that and masks are strictly smaller than implicit mask from
narrowed load.

Fixes PR37820.

Reviewers: samparker, RKSimon, nemanjai

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D48335

llvm-svn: 335137
2018-06-20 15:36:29 +00:00
Craig Topper ddd88a559f [DAGCombiner] Add some comments to some true/false arguments to make it obvious what they are. NFC
llvm-svn: 335095
2018-06-20 04:32:07 +00:00
Craig Topper 59da74370b [SelectionDAG] Don't crash on inline assembly errors when the inline assembly return type is a struct.
Summary:
If we get an error building the SelectionDAG for inline assembly we try to continue and still build the DAG.

But if the return type for the inline assembly is a struct we end up crashing because we try to create an UNDEF node with a struct type which isn't valid.

Instead we need to create an UNDEF for each element of the struct and join them with merge_values.

This patch relies on single operand merge_values being handled gracefully by getMergeValues. If the return type is void there will be no VTs returned by ComputeValueVTs and now we just return instead of calling setValue. Hopefully that's ok, I assumed nothing would need to look up the mapped value for void node.

Fixes PR37359

Reviewers: rengolin, rovka, echristo, efriedma, bogner

Reviewed By: efriedma

Subscribers: craig.topper, llvm-commits

Differential Revision: https://reviews.llvm.org/D46560

llvm-svn: 335093
2018-06-20 04:32:05 +00:00
Heejin Ahn 33c3fce592 [WebAssembly] Add WasmEHFuncInfo for unwind destination information
Summary:
Add WasmEHFuncInfo and routines to calculate and fill in this struct to
keep track of unwind destination information. This will be used in
other EH related passes.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, chrib, llvm-commits

Differential Revision: https://reviews.llvm.org/D48263

llvm-svn: 335005
2018-06-19 00:26:39 +00:00
Michael Berg 7b993d762f Utilize new SDNode flag functionality to expand current support for fadd
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed.

Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar

Reviewed By: spatel

Subscribers: wdng, nhaehnle

Differential Revision: https://reviews.llvm.org/D47909

llvm-svn: 334996
2018-06-18 23:44:59 +00:00
Michael Berg 932ba20af8 refactor of visitFADD for AllowNewConst cases
Summary: Refactoring for all constant cases which require AllowNewConst and some staging for future fmf usage.

Reviewers: spatel, hfinkel, wristow

Reviewed By: spatel

Subscribers: nhaehnle

Differential Revision: https://reviews.llvm.org/D48289

llvm-svn: 334984
2018-06-18 21:12:21 +00:00
Nirav Dave d4ff2f8a74 Avoid needing to walk out legalization tables. NFCI.
Relanding after fixing expensive check from modifying tables.

To avoid redundant work, during DAG legalization we keep tables
mapping pre-legalized SDValues to post-legalized SDValues and a
SDValue-to-SDValue map to enable fast node replacements. However, as
the keys are nodes which may be reused it is possible that an entry in
a table refers to a now deleted node N (that should have been renamed
by the value replacement map) while a new node N' exists. If N' is
then replaced that entry would be wrong. Previously we avoided this by
when potentially violating this property, walking every table and
updating all node pointers. This is very expensive but hopefully rare
occurance.

This patch assigns each instance of a SDValue used in legalization a
unique id and uses these ids in the legalization tables. This avoids
any such aliasing issue, avoiding the full table search and allowing
more aggressive incremental table pruning.

In some cases this is a 1000x speedup to compilation.

Reviewers: jyknight, echristo, bogner, tra

Reviewed By: bogner

Subscribers: dberris, grandinj, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47959

llvm-svn: 334880
2018-06-16 02:51:29 +00:00
Michael Berg 8e570c3390 Utilize new SDNode flag functionality to expand current support for fma
Summary: This patch originated from D47388 and is a proper subset of the originating changes, containing only the fmf optimization guard extensions.

Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar, rampitec, nhaehnle, nemanjai

Reviewed By: rampitec, nhaehnle

Subscribers: tpr, nemanjai, wdng

Differential Revision: https://reviews.llvm.org/D47918

llvm-svn: 334876
2018-06-16 00:03:06 +00:00
Francis Visoiu Mistrih dc705a6a89 Revert r334729 "[DAG] Avoid needing to walk out legalization tables. NFCI."
This reverts commit r334729.

llvm-svn: 334869
2018-06-15 23:05:41 +00:00
Francis Visoiu Mistrih 1c9df30eca Revert r334731 "Avoid unused variable in non-assert builds."
This reverts commit r334731.

It breaks EXPENSIVE_CHECKS bots.

llvm-svn: 334868
2018-06-15 23:05:40 +00:00
Cameron McInally 7caac670b2 [FPEnv] Expand constrained FP POWI
Modify ExpandStrictFPOp(...) to handle nodes that have scalar
operands. 

Also, add a Strict FMA test and do some other light cleanup in the
Strict FP code.

Differential Revision: https://reviews.llvm.org/D48149

llvm-svn: 334863
2018-06-15 20:57:55 +00:00
Michael Berg 02d1c6c0cf Utilize new SDNode flag functionality to expand current support for fdiv
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed.

Reviewers: spatel, hfinkel, wristow, arsenm

Reviewed By: spatel

Subscribers: wdng, nhaehnle

Differential Revision: https://reviews.llvm.org/D47954

llvm-svn: 334862
2018-06-15 20:44:55 +00:00
Matt Arsenault df2f4ef29d DAG: Fix creating concat_vectors with illegal type
Test passes as is, but fails with future patch to make v4i16/v4f16
legal.

llvm-svn: 334823
2018-06-15 12:09:15 +00:00
Michael Berg 0c20447a02 easing the constraint for isNegatibleForFree and GetNegatedExpression
Summary:
Here we relax the old constraint which utilized unsafe with the TargetOption flag HonorSignDependentRoundingFPMathOption, with the assertion that unsafe is no longer needed or never was required for correctness on FDIV/FMUL.  



Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar

Reviewed By: spatel

Subscribers: efriedma, wdng, tpr

Differential Revision: https://reviews.llvm.org/D48057

llvm-svn: 334769
2018-06-14 20:54:13 +00:00
Michael Berg 4663ceb63f updating isNegatibleForFree and GetNegatedExpression with fmf for fadd
Summary:  A FMF constraint is added to FADD with unsafe still available as the fallback

Reviewers: spatel, wristow, arsenm, hfinkel

Reviewed By: spatel

Subscribers: wdng

Differential Revision: https://reviews.llvm.org/D48180

llvm-svn: 334753
2018-06-14 18:48:31 +00:00
Nirav Dave 41e69a8e8b Avoid unused variable in non-assert builds.
llvm-svn: 334731
2018-06-14 15:55:15 +00:00
Nirav Dave a1ee983a95 [DAG] Avoid needing to walk out legalization tables. NFCI.
To avoid redundant work, during DAG legalization we keep tables
mapping pre-legalized SDValues to post-legalized SDValues and a
SDValue-to-SDValue map to enable fast node replacements. However, as
the keys are nodes which may be reused it is possible that an entry in
a table refers to a now deleted node N (that should have been renamed
by the value replacement map) while a new node N' exists. If N' is
then replaced that entry would be wrong. Previously we avoided this by
when potentially violating this property, walking every table and
updating all node pointers. This is very expensive but hopefully rare
occurance.

This patch assigns each instance of a SDValue used in legalization a
unique id and uses these ids in the legalization tables. This avoids
any such aliasing issue, avoiding the full table search and allowing
more aggressive incremental table pruning.

In some cases this is a 1000x speedup to compilation.

Reviewers: jyknight, echristo, bogner, tra

Reviewed By: bogner

Subscribers: dberris, grandinj, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47959

llvm-svn: 334729
2018-06-14 15:46:23 +00:00
Sanjay Patel 7d4929611c [DAGCombiner] remove hasOneUse() check from fadd constants transform
We're constant folding here, so we shouldn't check uses. This matches
the IR optimizer behavior.

The x86 test shows the expected win. The AArch64 test shows something
else. This only seems to happen if the "generic" AArch64 CPU model is 
used by MachineCombiner, so I'll file a bug report to follow-up.

llvm-svn: 334608
2018-06-13 15:22:48 +00:00
Cameron McInally f37bd01ddc [FPEnv] Expand constrained FP operations
Add a helper function to expand constrained FP operations as needed. 
Note that the Strict POWI operation is not handled in this patch since 
the format is slightly different from the others.

Differential Revision: https://reviews.llvm.org/D47491

llvm-svn: 334603
2018-06-13 14:32:12 +00:00
Krzysztof Parzyszek 82d284c1d2 [DAGCombiner] Recognize more patterns for ABS
Differential Revision: https://reviews.llvm.org/D47831

llvm-svn: 334553
2018-06-12 21:51:49 +00:00
Michael Berg 5d49f66570 Utilize new SDNode flag functionality to expand current support for fmul
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed for fmul.

Reviewers: spatel, hfinkel, wristow, arsenm

Reviewed By: spatel

Subscribers: nhaehnle, wdng

Differential Revision: https://reviews.llvm.org/D47911

llvm-svn: 334514
2018-06-12 16:13:11 +00:00
Krzysztof Parzyszek 3d671248ab [SelectionDAG] Provide default expansion for rotates
Implement default legalization of rotates: either in terms of the rotation
in the opposite direction (if legal), or in terms of shifts and ors.

Implement generating of rotate instructions for Hexagon. Hexagon only
supports rotates by an immediate value, so implement custom lowering of
ROTL/ROTR on Hexagon. If a rotate is not legal, use the default expansion.

Differential Revision: https://reviews.llvm.org/D47725

llvm-svn: 334497
2018-06-12 12:49:36 +00:00
Matt Arsenault 5615fa0a87 DAG: Fix extract_subvector combine for a single element
This would fail before because 1x vectors aren't legal,
so instead just use the scalar type.

Avoids regressions in a future AMDGPU commit to add
v4i16/v4f16 as legal types.

Test update is just the one test that this triggers
on in tree now. It wasn't checking anything before.
The result is completely  changed since the selects
are eliminated. Not sure if it's considered better
or not.

llvm-svn: 334440
2018-06-11 21:27:41 +00:00
Sanjay Patel 3e5c70cc1d [DAGCombiner] match vector compare and select sizes with extload operand (PR37427)
This patch started off much more general and ambitious, but it's been a nightmare 
seeing all the ways x86 vector codegen can go wrong.

So the code is still structured to allow extending easily, but it's currently 
limited in several ways:

1. Only handle cases with an extending load.
2. Only handle cases with a zero constant compare.
3. Ignore setcc with vector bitmask (SetCCWidth != 1) - so AVX512 should be unaffected.

The motivating case from PR37427:
https://bugs.llvm.org/show_bug.cgi?id=37427
...is the 1st test, and that shows the expected win - we eliminated the unnecessary 
intermediate cast.

There's a clear regression in the last test (sgt_zero_fp_select) because we longer 
recognize a 'SHRUNKBLEND' opportunity. I think that general problem is also present 
in sgt_zero, so I'll try to fix that in a follow-up. We need to match a sign-bit 
setcc from a sign-extended operand and remove it.

Differential Revision: https://reviews.llvm.org/D47330

llvm-svn: 334378
2018-06-10 23:09:50 +00:00
Craig Topper 61998289f9 Use SmallPtrSet instead of SmallSet in places where we iterate over the set.
SmallSet forwards to SmallPtrSet for pointer types. SmallPtrSet supports iteration, but a normal SmallSet doesn't. So if it wasn't for the forwarding, this wouldn't work.

These places were found by hiding the begin/end methods in the SmallSet forwarding

llvm-svn: 334343
2018-06-09 05:04:20 +00:00
Sanjay Patel 498564e6fb [DAGCombiner] clean up comments; NFC
llvm-svn: 334312
2018-06-08 18:00:46 +00:00
Michael Berg bf90d1f263 Utilize new SDNode flag functionality to expand current support for fsub
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed for fsub.

Reviewers: spatel, hfinkel, wristow, arsenm

Reviewed By: spatel

Subscribers: wdng

Differential Revision: https://reviews.llvm.org/D47910

llvm-svn: 334306
2018-06-08 17:39:50 +00:00
Sam Parker 16f963ba0d [DAGCombine] Fix for PR37667
While trying to propagate AND masks back to loads, we currently allow
one non-load node to be included as a leaf in chain. This fix now
limits that node to produce only a single data value.

Differential Revision: https://reviews.llvm.org/D47878

llvm-svn: 334268
2018-06-08 07:49:04 +00:00
Michael Berg 77b5be7ec6 propagate fast math flags via IR on fma and sub expressions
Summary: This change uses fmf subflags to guard fma optimizations as well as unsafe. These changes originated from D46483 and have been simplified via getNode.

Reviewers: spatel, arsenm, hfinkel, javed.absar

Reviewed By: spatel

Subscribers: nemanjai, wdng

Differential Revision: https://reviews.llvm.org/D47388

llvm-svn: 334242
2018-06-07 22:49:09 +00:00
Matt Arsenault e8eb567e17 DAG: Avoid bitcast/ext/build_vector combine
This avoids regressions in a future AMDGPU change
to make v4i16/v4f16 legal. For these types, build_vector
is implemented as bitcasted operations on v2i32. This
combine was creating v4i16s out of what would have been
already been a v2i32 build_vector, creating a mess
of nodes that never get cleaned up.

I'm not sure this is the right condition to check.
I initially tried just checking for the legality of the
new build_vector. This works for my case, but breaks dozens
of x86 tests. A Mips test seems to show some improvement
or at least a neutral change. I don't want to think
about how long it would take to analyze the set of
different x86 vector operations impacted.

Test included in future commit.

llvm-svn: 334218
2018-06-07 19:42:27 +00:00
Michael Berg cc1c4b6912 guard fsqrt with fmf sub flags
Summary:
This change uses fmf subflags to guard optimizations as well as unsafe. These changes originated from D46483.
It contains only context for fsqrt.


Reviewers: spatel, hfinkel, arsenm

Reviewed By: spatel

Subscribers: hfinkel, wdng, andrew.w.kaylor, wristow, efriedma, nemanjai

Differential Revision: https://reviews.llvm.org/D47749

llvm-svn: 334113
2018-06-06 18:47:55 +00:00
Michael Berg 96925fe0df guard fneg with fmf sub flags
Summary: This change uses fmf subflags to guard optimizations as well as unsafe. These changes originated from D46483.

Reviewers: spatel, hfinkel

Reviewed By: spatel

Subscribers: nemanjai

Differential Revision: https://reviews.llvm.org/D47389

llvm-svn: 334037
2018-06-05 18:49:47 +00:00
Matt Arsenault 191bc71541 DAG: Stop dropping invariant/dereferencable
When legalizing illegal FP load results, this was
for some reason dropping the invariant and dereferencable
memory flags. There doesn't seem to be any reason for this,
and the equivalent isn't done for integer loads.

Fixes an issue in a future AMDGPU commit where some identical
loads fail to merge because one of the loads ends up
dropping the flags.

llvm-svn: 334020
2018-06-05 14:52:24 +00:00
Reid Kleckner adcaddb6da Fix -Wcovered-switch-default warning and clang-format it
llvm-svn: 333967
2018-06-04 23:47:29 +00:00
Scott Linder ba81d7f1eb [CodeGen] Always update divergence in SelectionDAG::UpdateNodeOperands
Some overloads failed to update divergence.

Differential Revision: https://reviews.llvm.org/D47148

llvm-svn: 333947
2018-06-04 20:19:45 +00:00
Amaury Sechet da661e9236 [DAGcombine] Teach the combiner about -a = ~a + 1
Summary: This include variant for add, uaddo and addcarry. usubo and subcarry require the carry to be flipped to preserve semantic, but we chose to do the transform anyway in that case as to push the transform down the carry chain.

Reviewers: efriedma, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46505

llvm-svn: 333943
2018-06-04 19:23:22 +00:00
Amaury Sechet 93a7d2aa3c Get rid of SETCCE
Summary: It has been deprecated in favor of SETCCCARRY for a year now and isn't used by any in tree backend.

Reviewers: efriedma, craig.topper, dblaikie, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47685

llvm-svn: 333939
2018-06-04 18:36:22 +00:00
Krzysztof Parzyszek 623eb54361 [SelectionDAG] Add missing closing parentheses in comments, NFC
llvm-svn: 333907
2018-06-04 14:54:53 +00:00
Nirav Dave fc9a700f94 [DAG] Avoid checking for consecutive stores in store merge. NFCI.
llvm-svn: 333766
2018-06-01 15:05:55 +00:00
Nirav Dave 39ece11ae5 [DAG] Simplify Expression. NFC.
llvm-svn: 333765
2018-06-01 15:05:30 +00:00
Nirav Dave 0fc27acaa2 [DAG] Remove untriggerable check. NFCI.
Candidate check precludes this check.

llvm-svn: 333764
2018-06-01 15:05:05 +00:00
Nirav Dave a74921a696 [DAG] Prune store merge legal store check to stop invalid size. NFCI.
Do not consider store sizes large than the maximum legal store size.

llvm-svn: 333763
2018-06-01 15:04:40 +00:00
Krzysztof Parzyszek 0b6187c1a9 [SelectionDAG] Expand UADDO/USUBO into ADD/SUBCARRY if legal for target
Additionally, implement handling of ADD/SUBCARRY on Hexagon, utilizing
the UADDO/USUBO expansion.

Differential Revision: https://reviews.llvm.org/D47559

llvm-svn: 333751
2018-06-01 14:00:32 +00:00
Heejin Ahn 5ef4d5f9c1 [WebAssembly] Support instruction selection for catching exceptions
Summary:
This lowers exception catching-related instructions:
1. Lowers `wasm.catch` intrinsic to `catch` instruction
2. Removes `catchpad` and `cleanuppad` instructions; they are not
necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or
`MachineBasicBlock::isEHPad()` can be used instead.)
3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret`
and `cleanupret` instructions in isel, which will be replaced with other
instructions in `WebAssemblyExceptionPrepare` pass.
4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various
transformation for EH. Currently this pass only replaces `catchret` and
`cleanupret` instructions into appropriate wasm instructions to make
this patch successfully run until the end.

Currently this does not handle lowering of intrinsics related to LSDA
info generation (`wasm.landingpad.index` and `wasm.lsda`), because they
cannot be tested without implementing `EHStreamer`'s wasm-specific
handlers. They are marked as TODO, which is needed to make isel pass.
Also this does not generate `try` and `end_try` markers yet, which will
be handled in later patches.

This patch is based on the first wasm EH proposal.
(https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md)

Reviewers: dschuff, majnemer

Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D44090

llvm-svn: 333705
2018-05-31 22:25:54 +00:00
Matt Arsenault ab2b79cb97 DAG: Remove redundant version of getRegisterTypeForCallingConv
There seems to be no real reason to have these separate copies.
The existing implementations just copy each other for x86.
For Mips there is a subtle difference, which is just a bug
since it changes based on the context where which one was called.
Dropping this version, all tests pass. If I try to merge them
to match the removed version, a test fails.

llvm-svn: 333440
2018-05-29 17:42:26 +00:00
Cameron McInally b1bb60aec9 [StrictFP] Make getStrictFPOpcodeAction(...) more accessible
NFCI. This function will be reused in upcoming patches.

Differential Revision: https://reviews.llvm.org/D47380

llvm-svn: 333433
2018-05-29 16:49:32 +00:00
Heejin Ahn 1e4d35044f [WebAssembly] Add functions for EHScopes
Summary:
There are functions using the term 'funclet' to refer to both
1. an EH scopes, the structure of BBs that starts with
catchpad/cleanuppad and ends with catchret/cleanupret, and
2. a small function that gets outlined in AsmPrinter, which is the
original meaning of 'funclet'.

So far the two have been the same thing; EH scopes are always outlined
in AsmPrinter as funclets at the end of the compilation pipeline. But
now wasm also uses scope-based EH but does not outline those, so we now
need to correctly distinguish those two use cases in functions.

This patch splits `MachineBasicBlock::isFuncletEntry` into
`isFuncletEntry` and `isEHScopeEntry`, and
`MachineFunction::hasFunclets` into `hasFunclets` and `hasEHScopes`, in
order to distinguish the two different use cases. And this also changes
some uses of the term 'funclet' to 'scope' in `getFuncletMembership` and
change the function name to `getEHScopeMembership` because this function
is not about outlined funclets but about EH scope memberships.

This change is in the same vein as D45559.

Reviewers: majnemer, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D47005

llvm-svn: 333045
2018-05-23 00:32:46 +00:00
Sanjay Patel 17a870f07c [DAG] fold FP binops with undef operands to NaN
This is the FP sibling of D43141 with the corresponding IR change in rL327212.

We can't propagate undef here because if a variable operand is a NaN, these 
binops must propagate NaN. Neither global nor node-level fast-math makes a 
difference. If we have 'nnan', I think later folds can turn the NaN into undef.

The tests in X86/fp-undef.ll are meant to be the definitive verification for 
these folds - everything reduces identically now.

The other test changes are collateral damage. They may need to be altered to
preserve their intent.

Differential Revision: https://reviews.llvm.org/D47026

llvm-svn: 332920
2018-05-21 23:54:19 +00:00
Roman Lebedev 9f65d16d5d [DAGCombiner] isAllOnesConstantOrAllOnesSplatConstant(): look through bitcasts
Summary:
As pointed out in D46528, we errneously transform cases like `xor X, -1`,
even though we use said function.
It's because the `-1` is actually a bitcast there.
So i think we can just look through it in the function.

Differential Revision: https://reviews.llvm.org/D47156

llvm-svn: 332905
2018-05-21 21:41:10 +00:00