Commit Graph

3535 Commits

Author SHA1 Message Date
Tom Stellard ab411801b8 [cmake] Explicitly mark libraries defined in lib/ as "Component Libraries"
Summary:
Most libraries are defined in the lib/ directory but there are also a
few libraries defined in tools/ e.g. libLLVM, libLTO.  I'm defining
"Component Libraries" as libraries defined in lib/ that may be included in
libLLVM.so.  Explicitly marking the libraries in lib/ as component
libraries allows us to remove some fragile checks that attempt to
differentiate between lib/ libraries and tools/ libraires:

1. In tools/llvm-shlib, because
llvm_map_components_to_libnames(LIB_NAMES "all") returned a list of
all libraries defined in the whole project, there was custom code
needed to filter out libraries defined in tools/, none of which should
be included in libLLVM.so.  This code assumed that any library
defined as static was from lib/ and everything else should be
excluded.

With this change, llvm_map_components_to_libnames(LIB_NAMES, "all")
only returns libraries that have been added to the LLVM_COMPONENT_LIBS
global cmake property, so this custom filtering logic can be removed.
Doing this also fixes the build with BUILD_SHARED_LIBS=ON
and LLVM_BUILD_LLVM_DYLIB=ON.

2. There was some code in llvm_add_library that assumed that
libraries defined in lib/ would not have LLVM_LINK_COMPONENTS or
ARG_LINK_COMPONENTS set.  This is only true because libraries
defined lib lib/ use LLVMBuild.txt and don't set these values.
This code has been fixed now to check if the library has been
explicitly marked as a component library, which should now make it
easier to remove LLVMBuild at some point in the future.

I have tested this patch on Windows, MacOS and Linux with release builds
and the following combinations of CMake options:

- "" (No options)
- -DLLVM_BUILD_LLVM_DYLIB=ON
- -DLLVM_LINK_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_BUILD_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_LINK_LLVM_DYLIB=ON

Reviewers: beanz, smeenai, compnerd, phosek

Reviewed By: beanz

Subscribers: wuzish, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, mgorny, mehdi_amini, sbc100, jgravelle-google, hiraditya, aheejin, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, dang, Jim, lenary, s.egerton, pzheng, sameer.abuasal, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70179
2019-11-21 10:48:08 -08:00
Sanjay Patel 4ae0a13256 [InstCombine] add assert in SimplifyDemandedVectorElts and improve readability; NFC 2019-11-21 11:16:36 -05:00
Simon Tatham f4f77aa53e [ARM,MVE] Add InstCombine rules for pred_i2v / pred_v2i.
If you're writing C code using the ACLE MVE intrinsics that passes the
result of a vcmp as input to a predicated intrinsic, e.g.

  mve_pred16_t pred = vcmpeqq(v1, v2);
  v_out = vaddq_m(v_inactive, v3, v4, pred);

then clang's codegen for the compare intrinsic will create calls to
`@llvm.arm.mve.pred.v2i` to convert the output of `icmp` into an
`mve_pred16_t` integer representation, and then the next intrinsic
will call `@llvm.arm.mve.pred.i2v` to convert it straight back again.
This will be visible in the generated code as a `vmrs`/`vmsr` pair
that move the predicate value pointlessly out of `p0` and back into it again.

To prevent that, I've added InstCombine rules to remove round trips of
the form `v2i(i2v(x))` and `i2v(v2i(x))`. Also I've taught InstCombine
about the known and demanded bits of those intrinsics. As a result,
you now get just the generated code you wanted:

  vpt.u16 eq, q1, q2
  vaddt.u16 q0, q3, q4

Reviewers: ostannard, MarkMurrayARM, dmgreen

Reviewed By: dmgreen

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70313
2019-11-18 10:39:30 +00:00
Sanjay Patel 5d67d81f48 [InstCombine] prevent crashing/assert on shift constant expression (PR44028)
The binary operator cast implies an instruction, but the matcher for shift does not:
https://bugs.llvm.org/show_bug.cgi?id=44028
2019-11-17 17:31:09 -05:00
David Green 08390c52a2 [InstCombine] Canonicalize ssub.with.overflow with clamp to ssub.sat
Working on top of D69252, this adds canonicalisation patterns for ssub.with.overflow to ssub.sats.

Differential Revision: https://reviews.llvm.org/D69753
2019-11-17 10:45:11 +00:00
David Green 03fce6b12e [InstCombine] Canonicalize sadd.with.overflow with clamp to sadd.sat
This adds to D69245, adding extra signed patterns for folding from a
sadd_with_overflow to a sadd_sat. These are more complex than the
unsigned patterns, as the overflow can occur in either direction.

For the add case, the positive overflow can only occur if both of the
values are positive (same for both the values being negative). So there
is an extra select on whether to use the positive or negative overflow
limit.

Differential Revision: https://reviews.llvm.org/D69252
2019-11-17 10:42:39 +00:00
Francis Visoiu Mistrih a4c76be506 [InstCombine] Don't use getFirstNonPHI in FoldIntegerTypedPHI
getFirstNonPHI iterates over all the instructions in a block until it
finds a non-PHI.

Then, the loop starts from the beginning of the block and goes through
all the instructions until it reaches the instruction found by
getFirstNonPHI.

Instead of doing that, just stop when a non-PHI is found.

This reduces the compile-time of a test case discussed in
https://reviews.llvm.org/D47023 by 13x.

Not entirely sure how to come up with a test case for this since it's a
compile time issue that would significantly slow down running the tests.

Differential Revision: https://reviews.llvm.org/D70016
2019-11-14 17:52:01 -08:00
Reid Kleckner 4c1a1d3cf9 Add missing includes needed to prune LLVMContext.h include, NFC
These are a pre-requisite to removing #include "llvm/Support/Options.h"
from LLVMContext.h: https://reviews.llvm.org/D70280
2019-11-14 15:23:15 -08:00
Sanjay Patel 385572ccfe [InstCombine] remove duplicate code for simplifying a shuffle; NFCI
The transform is already handled by InstSimplify or earlier
in InstCombine, so trying to do it again is not necessary.
2019-11-14 13:12:25 -05:00
Daniil Suchkov 4c9d0da838 Revert "[InstCombine] Fold PHIs with equal incoming pointers"
This reverts commit a2f6ae9abf.
It is reverted due to clang-cmake-armv7-selfhost buildbot failure.
2019-11-14 17:42:01 +07:00
Daniil Suchkov a2f6ae9abf [InstCombine] Fold PHIs with equal incoming pointers
This is a resubmission of bbb29738b5 that
was reverted due to clang tests failures. It includes the fix and
additional IR tests for the missed case.

Summary:
In case when all incoming values of a PHI are equal pointers, this
transformation inserts a definition of such a pointer right after
definition of the base pointer and replaces with this value both PHI and
all it's incoming pointers. Primary goal of this transformation is
canonicalization of this pattern in order to enable optimizations that
can't handle PHIs. Non-inbounds pointers aren't currently supported.

Reviewers: spatel, RKSimon, lebedev.ri, apilipenko

Reviewed By: apilipenko

Tags: #llvm

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D68128
2019-11-14 17:04:32 +07:00
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Sanjay Patel 3d6b53980c [InstCombine] propagate fast-math-flags (FMF) to select when inverting fcmp+select
As noted by the FIXME comment, this is not correct based on our current FMF semantics.
We should be propagating FMF from the final value in a sequence (in this case the
'select'). So the behavior even without this patch is wrong, but we did not allow FMF
on 'select' until recently.

But if we do the correct thing right now in this patch, we'll inevitably introduce
regressions because we have not wired up FMF propagation for 'phi' and 'select' in
other passes (like SimplifyCFG) or other places in InstCombine. I'm not seeing a
better incremental way to make progress.

That said, the potential extra damage over the existing wrong behavior from this
patch is very limited. AFAIK, the only way to have different FMF on IR in the same
function is if we have LTO inlined IR from 2 modules that were compiled using
different fast-math settings.

As seen in the tests, we may actually see some improvements with this patch because
adding the FMF to the 'select' allows matching to min/max intrinsics that were
previously missed (in the common case, the 'fcmp' and 'select' should have identical
FMF to begin with).

Next steps in the transition:

    Make similar changes in instcombine as needed.
    Enable phi-to-select FMF propagation in SimplifyCFG.
    Remove dependencies on fcmp with FMF.
    Deprecate FMF on fcmp.

Differential Revision: https://reviews.llvm.org/D69720
2019-11-13 10:38:42 -05:00
Florian Hahn f7499011ca [InstCombine] Avoid moving ops that do restrict undef across shuffles.
I think we have to be a bit more careful when it comes to moving
ops across shuffles, if the op does restrict undef. For example, without
this patch, we would move 'and %v, <0, 0, -1, -1>' over a
'shufflevector %a, undef, <undef, undef, 1, 2>'. As a result, the first
2 lanes of the result are undef after the combine, but they really
should be 0, unless I am missing something.

For ops that do fold to undef on undef operands, the current behavior
should be fine. I've add conservative check OpDoesRestrictUndef, maybe
there's a better existing utility?

Reviewers: spatel, RKSimon, lebedev.ri

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D70093
2019-11-13 13:40:34 +00:00
Daniil Suchkov cba4a27745 Temporarily revert "[InstCombine] Fold PHIs with equal incoming pointers"
Revert due to sanitizer-windows buildbot failure.

This reverts commit bbb29738b5.
2019-11-13 17:14:11 +07:00
Daniil Suchkov bbb29738b5 [InstCombine] Fold PHIs with equal incoming pointers
In case when all incoming values of a PHI are equal pointers, this
transformation inserts a definition of such a pointer right after
definition of the base pointer and replaces with this value both PHI and
all it's incoming pointers. Primary goal of this transformation is
canonicalization of this pattern in order to enable optimizations that
can't handle PHIs. Non-inbounds pointers aren't currently supported.

Reviewers: spatel, RKSimon, lebedev.ri, apilipenko

Reviewed By: apilipenko

Tags: #llvm

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D68128
2019-11-13 17:00:34 +07:00
Diana Picus 7f1dcc8952 [InstCombine] Skip scalable vectors in combineLoadToOperationType
Don't try to canonicalize loads to scalable vector types to loads
of integers.

This removes one assertion when trying to use a TypeSize as a parameter
to DataLayout::isLegalInteger. It does not handle the second part of the
function (which looks at bitcasts).

This patch also contains a NFC fix for Load Analysis, where a variable
initialization that would cause the same assertion is moved closer to
its use. This allows us to run the new test for InstCombine without
having to teach LocationSize to play nicely with scalable vectors.

Differential Revision: https://reviews.llvm.org/D70075
2019-11-12 12:27:09 +01:00
aqjune 4187cb138b Add InstCombine/InstructionSimplify support for Freeze Instruction
Summary:
- Add llvm::SimplifyFreezeInst
- Add InstCombiner::visitFreeze
- Add llvm tests

Reviewers: majnemer, sanjoy, reames, lebedev.ri, spatel

Reviewed By: reames, lebedev.ri

Subscribers: reames, lebedev.ri, filcab, regehr, trentxintong, llvm-commits

Differential Revision: https://reviews.llvm.org/D29013
2019-11-12 12:13:26 +09:00
Sanjay Patel 29f5d1670c Revert "[InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (3rd try)"
This reverts commit 3db8a3ef86.
This caused a different memory-sanitizer failure than earlier attempts,
but it's still not right.
2019-11-11 09:56:03 -05:00
Sanjay Patel 3db8a3ef86 [InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (3rd try)
Re-try because earlier attempts were reverted due to use-after-free.
Hopefully, diagnosed correctly this time - we replace/remove the
invariant.start first rather than the invariant.end to avoid angering
worklist-based iteration.

We gather a set of white-listed instructions in isAllocSiteRemovable() and then
replace/erase them. But we don't know in general if the instructions in the set
have uses amongst themselves, so order of deletion makes a difference.

There's already a special-case for the llvm.objectsize intrinsic, so add another
for llvm.invariant.start.

Should fix:
https://bugs.llvm.org/show_bug.cgi?id=43723

Differential Revision: https://reviews.llvm.org/D69977
2019-11-11 09:29:40 -05:00
Jay Foad 9323ef4ecc [InstCombine] Simplify binary op when only one operand is a select
Summary:
SimplifySelectsFeedingBinaryOp simplified binary ops when both operands
were selects with the same condition. This patch extends it to handle
these cases where only one operand is a select:

X op (C ? P : Q) -> C ? (X op P) : (X op Q)
  // if X op P and X op Q both simplify
(C ? P : Q) op Y -> C ? (P op Y) : (Q op Y)
  // if P op Y and Q op Y both simplify

For example: X *fast (C ? 1.0 : 0.0) -> C ? X : 0.0

Reviewers: mcberg2017, majnemer, craig.topper, qcolombet, mcrosier

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64713
2019-11-11 10:01:59 +00:00
Craig Topper aafde063aa [InstCombine] Turn (extractelement <1 x i64/double> (bitcast (x86_mmx))) into a single bitcast from x86_mmx to i64/double.
The _m64 type is represented in IR as <1 x i64>. The x86-64 ABI
on Linux passes <1 x i64> as a double. MMX intrinsics use x86_mmx
type in IR.These things result in a lot of bitcasts in mmx code.
There's another instcombine that tries to turn bitcast <1 x i64>
to double into extractelement and a bitcast.

The combine here tries to reverse this extractelement conversion
if we see an mmx type.
2019-11-10 16:25:25 -08:00
Sanjay Patel d115b9fd4a Revert "[InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (2nd try)"
This reverts commit 56b2aee187.
Still causes a use-after-free on sanitizer bots.
2019-11-10 18:47:49 -05:00
Sanjay Patel 56b2aee187 [InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (2nd try)
Re-try rGef02831f0a4e (reverted due to use-after-free), but bail out completely
if we encounter an unexpected llvm.invariant.start.

We gather a set of white-listed instructions in isAllocSiteRemovable() and then
replace/erase them. But we don't know in general if the instructions in the set
have uses amongst themselves, so order of deletion makes a difference.

There's already a special-case for the llvm.objectsize intrinsic, so add another
for llvm.invariant.end.

Should fix:
https://bugs.llvm.org/show_bug.cgi?id=43723

Differential Revision: https://reviews.llvm.org/D69977
2019-11-10 17:26:36 -05:00
Sanjay Patel b0ac26a632 Revert "[InstCombine] avoid crash from deleting an instruction that still has uses (PR43723)"
This reverts commit ef02831f0a.
Sanitizer bots fail with this change.
2019-11-10 11:18:05 -05:00
Sanjay Patel ef02831f0a [InstCombine] avoid crash from deleting an instruction that still has uses (PR43723)
We gather a set of white-listed instructions in isAllocSiteRemovable() and then
replace/erase them. But we don't know in general if the instructions in the set
have uses amongst themselves, so order of deletion makes a difference.

There's already a special-case for the llvm.objectsize intrinsic, so add another
for llvm.invariant.end.

Should fix:
https://bugs.llvm.org/show_bug.cgi?id=43723

Differential Revision: https://reviews.llvm.org/D69977
2019-11-10 09:18:11 -05:00
Jay Foad d162e02cee Refactor SimplifySelectsFeedingBinaryOp for D64713. NFC. 2019-11-09 09:28:22 +00:00
Craig Topper 6749dc3446 [InstCombine] Don't transform bitcasts between x86_mmx and v1i64 into insertelement/extractelement
x86_mmx is conceptually a vector already. Don't introduce an extra conversion between it and scalar i64.

I'm using VectorType::isValidElementType which checks for floating point, integer, and pointers to hopefully make this more readable than just blacklisting x86_mmx.

Differential Revision: https://reviews.llvm.org/D69964
2019-11-07 15:14:13 -08:00
Vedant Kumar a087b78bc4 Wrong debug info generated at -O2 (-O0 is correct)
Instcombiner pass was erasing trivially dead instruction without updating dependent llvm.dbg.value.
which was not showing programmer current state of variables while debugging.
As a part of this fix I did following,
Iterate throught all the users (llvm.dbg) of a instruction which is trivially dead and set each if them undef, Before deleting the instruction.
Now user will see optimized out, when try to print those variables.
This fixes
https://bugs.llvm.org/show_bug.cgi?id=43893

This is my first fix to llvm.

Patch by kamlesh kumar!

Differential Revision: https://reviews.llvm.org/D69809
2019-11-07 11:19:41 -08:00
Sanjay Patel d9ccb6367a [InstCombine] canonicalize shift+logic+shift to reduce dependency chain
shift (logic (shift X, C0), Y), C1 --> logic (shift X, C0+C1), (shift Y, C1)

This is an IR translation of an existing SDAG transform added here:
rL370617

So we again have 9 possible patterns with a commuted IR variant of each pattern:
https://rise4fun.com/Alive/VlI
https://rise4fun.com/Alive/n1m
https://rise4fun.com/Alive/1Vn

Part of the motivation is to allow easier recognition and subsequent
canonicalization of bswap patterns as discussed in PR43146:
https://bugs.llvm.org/show_bug.cgi?id=43146

We had to delay this transform because it used to allow the SLP vectorizer
to create awful reductions out of simple load-combines.
That problem was fixed with:
rL375025
(we'll bring back load combining in IR someday...)

The backend is also better equipped to deal with these patterns now
using hooks like TLI.getShiftAmountThreshold().

The only remaining potential controversy is that the -reassociate pass
tends to reverse this kind of pattern (to help GVN?). But since -reassociate
doesn't do anything with these specific patterns, there is no conflict currently.

Finally, there's a new pass proposal at D67383 for general tree-height-reduction
reassociation, and it could use a cost model to decide how to optimally rearrange
these kinds of ops for a target. That patch appears to be stalled.

Differential Revision: https://reviews.llvm.org/D69842
2019-11-07 12:09:45 -05:00
Roman Lebedev ccf1a5f4bb
[InstCombine] dropRedundantMaskingOfLeftShiftInput(): truncation (PR42563)
Summary:
That fold keeps growing and growing :(
I think this may be one of the last pieces for it.

Since D67677/D67725, the fold knowns the general form
of the pattern - where some masking is needed:
https://rise4fun.com/Alive/F5R
https://rise4fun.com/Alive/gslRa

But there is one more huge piece missing - if you are extracting some bits,
it is not impossible that the origin is wider than the extraction,
i.e. there may be a truncation. And we don't deal with that yet.

But we can, and the generalization remains fully identical:
https://rise4fun.com/Alive/Uar
https://rise4fun.com/Alive/5SW

After a preparatory cleanup i think the diff looks rather clean.

One missing piece is that in some patterns (especially pat. b),
`-1` only needs to be `-1` in final type, but that is for later..

https://bugs.llvm.org/show_bug.cgi?id=42563

Reviewers: spatel, nikic

Reviewed By: spatel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69125
2019-11-05 12:41:26 +03:00
Dávid Bolvanský 058b5028de Reland '[InstructionCombining] Fixed null check after dereferencing warning. NFCI.' 2019-11-03 20:34:54 +01:00
Dávid Bolvanský 5b37c018d5 Revert "[InstructionCombining] Fixed null check after dereferencing warning. NFCI."
This reverts commit 8308187fd9. This exposed a bug.
2019-11-03 20:31:05 +01:00
Dávid Bolvanský d825ed24d2 Revert "[InstructionCompares] Fixed null check after dereferencing warning. NFCI."
This reverts commit b8685cf304.
2019-11-03 20:24:01 +01:00
Dávid Bolvanský b8685cf304 [InstructionCompares] Fixed null check after dereferencing warning. NFCI. 2019-11-03 20:13:45 +01:00
Dávid Bolvanský 8308187fd9 [InstructionCombining] Fixed null check after dereferencing warning. NFCI. 2019-11-03 20:10:46 +01:00
Sanjay Patel a2240f57e7 [InstCombine] simplify fcmp+select canonicalization; NFCI
We had 2 blocks of code that are nearly identical. Existing
regression tests should cover both of the patterns.
2019-10-31 13:13:32 -04:00
David Green a5f7bc0de7 [InstCombine] Canonicalize uadd.with.overflow to uadd.sat
This adds some patterns to transform uadd.with.overflow to uadd.sat
(with usub.with.overflow to usub.sat too). The patterns selects from
UINTMAX (or 0 for subs) depending on whether the operation overflowed.

Signed patterns are a little more involved (they can wrap in two
directions), but can be added here in a followup patch too.

Differential Revision: https://reviews.llvm.org/D69245
2019-10-31 12:45:38 +00:00
tyker c3b06d0c39 [InstCombine] keep assumption before sinking calls
Summary:
in the following C code the branch is not removed by clang in O3.
```
int f1(char* p) {
    int i1 = __builtin_strlen(p);
    if (!p)
        return -1;
    return i1;
}
```
The issue is that the call to strlen is sunk to the following block by instcombine. In its new place the call to strlen doesn't dominate the use in the icmp anymore so value tracking can't see that p cannot be null.
This patch resolves the issue by inserting an assumption at the place of the call before sinking a call when that call can be used to prove an argument to be nonnull.
This resolves this issue at O3.

Reviewers: majnemer, xbolva00, fhahn, jdoerfert, spatel, efriedma

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69477
2019-10-31 00:15:19 +01:00
Sanjay Patel a22282be54 [InstCombine] make icmp vector canonicalization safe for constant with undef elements
This is a fix for:
https://bugs.llvm.org/show_bug.cgi?id=43730
...and as shown there, we have existing test cases that show potential miscompiles.

We could just bail out for vector constants that contain any undef elements, or we can do as shown here:
allow the transform, but replace the undefs with a safe value.

For most of the tests shown, this results in a full splat constant (no undefs) which is probably a win
for further IR analysis because we conservatively don't match undefs in most cases. Codegen can probably
recover these kinds of undef lanes via demanded elements analysis if that's profitable.

Differential Revision: https://reviews.llvm.org/D69519
2019-10-29 10:58:14 -04:00
Sanjay Patel a1e8ad4f2f [IR] move helper function to replace undef constant (elements) with fixed constants
This is the NFC part of D69519.
We had this functionality locally in instcombine, but it can be used
elsewhere, so hoisting it to Constant class.
2019-10-29 08:52:10 -04:00
David Green bf21f0d489 [InstCombine] Extra combine for uadd_sat
This is an extra fold for a canonical form of uadd_sat, as shown in
D68651. It essentially selects uadd from an add and a select.

Differential Revision: https://reviews.llvm.org/D69244
2019-10-28 15:21:16 +00:00
Benjamin Kramer 6f0bb77037 [InstCombine] Fold one-use variable into assert
Avoids warnings in Release builds. NFC.
2019-10-24 17:57:24 +02:00
Simon Tatham e5f485c3bd [InstCombine] Known-bits optimization for ARM MVE VADC.
The MVE VADC instruction reads and writes the carry bit at bit 29 of
the FPSCR register. The corresponding ACLE intrinsic is specified to
work with an integer in which the carry bit is stored at bit 0. So if
a user writes a code sequence in C that passes the carry from one VADC
to the next, like this,

    s0 = vadcq_u32(a0, b0, &carry);
    s1 = vadcq_u32(a1, b1, &carry);

then clang will generate IR for each of those operations that shifts
the carry bit up into bit 29 before the VADC, and after it, shifts it
back down and masks off all but the low bit. But in this situation
what you really wanted was two consecutive VADC instructions, so that
the second one directly reads the value left in FPSCR by the first,
without wasting several instructions on pointlessly clearing the other
flag bits in between.

This commit explains to InstCombine that the other bits of the flags
operand don't matter, and adds a test that demonstrates that all the
code between the two VADC instructions can be optimized away as a
result.

Reviewers: dmgreen, miyuki, ostannard

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67162
2019-10-24 16:33:13 +01:00
David Green 186155b89c [InstCombine] Signed saturation patterns
This adds an instcombine matcher for code that attempts to perform signed
saturating arithmetic by casting to a higher type. Unsigned cases are already
matched, this adds extra matches for the more complex signed cases, which
involves matching the min(max(add a b)) nodes with proper extends to ensure
legality.

Differential Revision: https://reviews.llvm.org/D68651

llvm-svn: 375505
2019-10-22 15:39:47 +00:00
Guillaume Chatelet 5b99c189b3 [Alignment][NFC] Convert StoreInst to MaybeAlign
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69303

llvm-svn: 375499
2019-10-22 12:55:32 +00:00
Guillaume Chatelet 734c74ba14 [Alignment][NFC] Convert LoadInst to MaybeAlign
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69302

llvm-svn: 375498
2019-10-22 12:35:55 +00:00
Guillaume Chatelet 301b4128ac [Alignment][NFC] Finish transition for `Loads`
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: hiraditya, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69253

llvm-svn: 375419
2019-10-21 15:10:26 +00:00
Roman Lebedev 9948fac6c1 [NFC][InstCombine] Fixup comments
As noted in post-commit review of rL375378375378.

llvm-svn: 375397
2019-10-21 08:21:54 +00:00
Piotr Sobczak a861c9aef9 [InstCombine] Allow values with multiple users in SimplifyDemandedVectorElts
Summary:
Allow for ignoring the check for a single use in SimplifyDemandedVectorElts
to be able to simplify operands if DemandedElts is known to contain
the union of elements used by all users.
It is a responsibility of a caller of SimplifyDemandedVectorElts to
supply correct DemandedElts.

Simplify a series of extractelement instructions if only a subset of
elements is used.

Reviewers: reames, arsenm, majnemer, nhaehnle

Reviewed By: nhaehnle

Subscribers: wdng, jvesely, nhaehnle, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67345

llvm-svn: 375395
2019-10-21 08:12:47 +00:00