Commit Graph

668 Commits

Author SHA1 Message Date
Sanjay Patel a2eb55de99 [InstSimplify] add tests for logic+icmp folds for nullptr; NFC
See discussion in D78430.
2020-04-19 10:42:08 -04:00
Sanjay Patel 02b070ed49 [InstSimplify] add tests for logic-of-icmp with min/max constant; NFC
See PR45510:
https://bugs.llvm.org/show_bug.cgi?id=45510

We had partial coverage for some of these patterns, so removing duplicate tests
with the complete set in the new test file.
2020-04-19 08:24:38 -04:00
Sanjay Patel c72f49cc57 [InstSimplify] add test for select that should not be simplified; NFC
See discussion in D77868
2020-04-14 13:57:30 -04:00
Sanjay Patel 73bebc9445 [InstSimplify] add tests for folding bool select to logic; NFC 2020-04-10 09:08:00 -04:00
Simon Pilgrim 6d24dd7ed1 [InstSimplify] Regenerate compares tests to fix issue reported on D77354 2020-04-03 17:34:56 +01:00
Serge Pavlov f398739152 [FEnv] Constfold some unary constrained operations
This change implements constant folding to constrained versions of
intrinsics, implementing rounding: floor, ceil, trunc, round, rint and
nearbyint.

Differential Revision: https://reviews.llvm.org/D72930
2020-03-28 12:28:33 +07:00
Sanjay Patel 88b493a838 [ValueTracking] improve undef/poison analysis for constant vectors
Differential Revision: https://reviews.llvm.org/D76702
2020-03-24 13:35:47 -04:00
Sanjay Patel 6c3c7a0dd6 [InstSimplify] add tests for freeze(constexpr); NFC 2020-03-24 11:39:19 -04:00
Sanjay Patel 58ec867a3b [InstSimplify] add more tests for freeze(constant); NFC
These should really be moved over to a ConstantFolding test file,
but since this may overlap with the in-progress D76010 and similar
tests already exist here, we can do that as a later cleanup.
2020-03-24 09:53:49 -04:00
Juneyoung Lee 5792c2236d Add test cases that are addressed by D76010 2020-03-23 13:49:29 +09:00
Simon Pilgrim 7f764fa18f [ValueTracking] Add some initial isKnownNonZero DemandedElts support (PR36319) 2020-03-20 13:29:00 +00:00
Simon Pilgrim c1efdbcbe0 [ValueTracking] Add computeKnownBits DemandedElts support to shift instructions (PR36319) 2020-03-20 11:08:08 +00:00
Nikita Popov a09ff56b5b [Tests] Regenerate some test checks; NFC 2020-03-20 12:06:53 +01:00
Nikita Popov 0372768776 [InstCombine] Simplify calls with "returned" attribute
If a call argument has the "returned" attribute, we can simplify
the call to the value of that argument. This was already partially
handled by InstSimplify/InstCombine for the case where the argument
is an integer constant, and the result is thus known via known bits.
The non-constant (or non-int) argument cases weren't handled though.

This previously landed as an InstSimplify transform, but was reverted
due to assertion failures when compiling the Linux kernel. The reason
is that simplifying a call to another call breaks assumptions in
call graph updating during inlining. As the code is not easy to fix,
and there is no particularly strong motivation for having this in
InstSimplify, the transform is only performed in InstCombine instead.

Differential Revision: https://reviews.llvm.org/D75815
2020-03-20 10:23:39 +01:00
Simon Pilgrim 95b6f62efb [InstSimplify] Add some vector shift tests to show lack of DemandedElts support 2020-03-19 22:09:51 +00:00
Simon Pilgrim 0b458d4dca [ValueTracking] Add computeKnownBits DemandedElts support to ADD/SUB/MUL instructions (PR36319) 2020-03-19 12:41:29 +00:00
Simon Pilgrim 7ce7f78963 [InstSimplify] Add missing vector ADD+SUB tests to show lack of DemandedElts support 2020-03-19 11:27:27 +00:00
Simon Pilgrim d259e31a17 [InstSimplify] Add missing vector MUL tests to show lack of DemandedElts support 2020-03-19 11:27:27 +00:00
Simon Pilgrim 99336bf95a [ValueTracking] Add computeKnownBits DemandedElts support to masked add instructions (PR36319) 2020-03-18 21:50:56 +00:00
Simon Pilgrim 49bdfd888d [InstSimplify] Add missing vector masked add tests to show lack of DemandedElts support 2020-03-18 21:04:54 +00:00
Simon Pilgrim 9d40292a64 [ValueTracking] Add computeKnownBits DemandedElts support to XOR instructions (PR36319) 2020-03-18 20:24:14 +00:00
Simon Pilgrim 47ce1406c8 [InstSimplify] Add missing vector OR test to show lack of DemandedElts support 2020-03-18 20:24:14 +00:00
Simon Pilgrim 6bdb0efa42 [InstSimplify] Regenerate OR tests 2020-03-18 20:24:13 +00:00
Simon Pilgrim 1010c44b4c [ValueTracking] Add computeKnownBits DemandedElts support to EXTRACTELEMENT/OR/BSWAP/BITREVERSE instructions (PR36319)
These are all covered by the bswap/bitreverse vector tests.
2020-03-18 18:49:58 +00:00
Simon Pilgrim 9c6458ecf8 [InstSimplify] Add bitreverse/bswap vector tests
Shows missing DemandedElts support (PR36319)
2020-03-18 18:17:10 +00:00
Huihui Zhang 1bf0c99375 [ValueTracking][SVE] Fix isGEPKnownNonNull for scalable vector.
Summary:
DataLayout::getTypeAllocSize() return TypeSize. For cases where the
scalable property doesn't matter, we should explicitly call getKnownMinSize()
to avoid implicit type conversion to uint64_t, which is not valid for scalable
vector type.

Reviewers: sdesmalen, efriedma, apazos, reames

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76260
2020-03-17 11:31:30 -07:00
Nico Weber 623cb95eb3 Revert "[InstSimplify] Simplify calls with "returned" attribute"
This reverts commit 45555c3819.
Causes clang crashes in some causes, see comments on
https://reviews.llvm.org/D75815 for details (including
repro steps).
2020-03-16 15:21:30 -04:00
Huihui Zhang 0616e9964b [InstSimplify][SVE] Fix SimplifyGEPInst for scalable vector.
Summary:
Skip folds that rely on DataLayout::getTypeAllocSize(). For scalable
vector, only minimal type alloc size is known at compile-time.

Reviewers: sdesmalen, efriedma, spatel, apazos

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75892
2020-03-16 11:46:12 -07:00
Huihui Zhang 118abf2017 [SVE] Update API ConstantVector::getSplat() to use ElementCount.
Summary:
Support ConstantInt::get() and Constant::getAllOnesValue() for scalable
vector type, this requires ConstantVector::getSplat() to take in 'ElementCount',
instead of 'unsigned' number of element count.

This change is needed for D73753.

Reviewers: sdesmalen, efriedma, apazos, spatel, huntergr, willlovett

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, cfe-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74386
2020-03-12 13:22:41 -07:00
Sanjay Patel a66dc755db [InstSimplify] simplify FP ops harder with FMF (part 2)
This is part of the IR sibling for:
D75576

Related transform committed with:
rG8ec71585719d
2020-03-12 09:53:20 -04:00
Sanjay Patel 8ec7158571 [InstSimplify] simplify FP ops harder with FMF
This is part of the IR sibling for:
D75576

(I'm splitting part of the transform as a separate commit
to reduce risk. I don't know of any bugs that might be
exposed by this improved folding, but it's hard to see
those in advance...)
2020-03-12 09:13:28 -04:00
Sanjay Patel d748e759d5 [InstSimplify] add tests for FP poison; NFC
Adapted from codegen tests seen in D75576.
2020-03-12 08:32:04 -04:00
Huihui Zhang 8f52573962 [InstSimplify][SVE] Fix SimplifyInsert/ExtractElementInst for scalable vector.
Summary:
For scalable vector, index out-of-bound can not be determined at compile-time.
The same apply for VectorUtil findScalarElement().

Add test cases to check the functionality of SimplifyInsert/ExtractElementInst for scalable vector.

Reviewers: sdesmalen, efriedma, spatel, apazos

Reviewed By: efriedma

Subscribers: cameron.mcinally, tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75782
2020-03-11 15:09:56 -07:00
Nikita Popov 45555c3819 [InstSimplify] Simplify calls with "returned" attribute
If a call argument has the "returned" attribute, we can simplify
the call to the value of that argument. The "-inst-simplify" pass
already handled this for the constant integer argument case via
known bits, which is invoked in SimplifyInstruction. However,
non-constant (or non-int) arguments are not handled at all right now.

This addresses one of the regressions from D75801.

Differential Revision: https://reviews.llvm.org/D75815
2020-03-09 18:53:47 +01:00
Nikita Popov 829d377a98 [InstSimplify] Don't simplify musttail calls
As pointed out by jdoerfert on D75815, we must be careful when
simplifying musttail calls: We can only replace the return value
if we can eliminate the call entirely. As we can't make this
guarantee for all consumers of InstSimplify, this patch disables
simplification of musttail calls. Without this patch, musttail
simplification currently results in module verification errors.

Differential Revision: https://reviews.llvm.org/D75824
2020-03-09 18:46:56 +01:00
Nikita Popov d2dab92f01 [InstSimplify] Add tests for "returned" attribute; NFC 2020-03-07 17:17:21 +01:00
Juneyoung Lee d7267ee194 [ValueTracking] Let isGuaranteedNotToBeUndefOrPoison look into branch conditions of dominating blocks' terminators
Summary:
```
  br i1 c, BB1, BB2:
BB1:
  use1(c)
BB2:
  use2(c)
```

In BB1 and BB2, c is never undef or poison because otherwise the branch would have triggered UB.

This is a resubmission of 952ad47 with crash fix of llvm/test/Transforms/LoopRotate/freeze-crash.ll.

Checked with Alive2

Reviewers: xbolva00, spatel, lebedev.ri, reames, jdoerfert, nlopes, sanjoy

Reviewed By: reames

Subscribers: jdoerfert, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75401
2020-03-06 01:08:35 +09:00
Daniil Suchkov 3db48f9324 Revert "[ValueTracking] Let isGuaranteedNotToBeUndefOrPoison look into branch conditions of dominating blocks' terminators"
That commit causes SIGSEGV on some simple tests.
This reverts commit 952ad4701c.
2020-03-05 16:32:36 +07:00
Nikita Popov c6ff3c9bad [InstSimplify] Constant fold icmp of gep
InstSimplify can fold icmps of gep where the base pointers are the
same and the offsets are constant. It does so by constructing a
constant expression icmp and assumes that it gets folded -- but
this doesn't actually happen, because GEP expressions can usually
only be folded by the target-dependent constant folding layer.
As such, we need to explicitly invoke it here.

Differential Revision: https://reviews.llvm.org/D75407
2020-03-04 23:16:52 +01:00
Nikita Popov a99b97b818 [InstSimplify] Add additional icmp of gep folding test; NFC 2020-03-04 18:27:01 +01:00
Nikita Popov 0940c32385 [InstSimplify] Regenerate compare.ll checks; NFC 2020-03-04 18:26:42 +01:00
Juneyoung Lee 952ad4701c [ValueTracking] Let isGuaranteedNotToBeUndefOrPoison look into branch conditions of dominating blocks' terminators
Summary:
```
  br i1 c, BB1, BB2:
BB1:
  use1(c)
BB2:
  use2(c)
```

In BB1 and BB2, c is never undef or poison because otherwise the branch would have triggered UB.

Checked with Alive2

Reviewers: xbolva00, spatel, lebedev.ri, reames, jdoerfert, nlopes, sanjoy

Reviewed By: reames

Subscribers: jdoerfert, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75401
2020-03-04 11:43:31 +09:00
Sanjay Patel 7ddbf802cf [ConstantFold] add/move tests for FP with undef operand; NFC 2020-02-20 15:07:11 -05:00
Ehud Katz 2d77e0b9f2 Fix tests of constant folding of fp operations on NaN values
Fix failures introduced due to change rG0b336b6048ae.
2020-01-21 21:48:07 +02:00
Sanjay Patel da9c93f330 [InstSimplify] fold select of vector constants that include undef elements
As mentioned in D72643, we'd like to be able to assert that any select
of equivalent constants has been removed before we're deep into InstCombine.

But there's a loophole in that assertion for vectors with undef elements
that don't match exactly.

This patch should close that gap. If we have undefs, we can't safely
propagate those unless both constants elements for that lane are undef.

Differential Revision: https://reviews.llvm.org/D72958
2020-01-20 08:48:32 -05:00
Sanjay Patel a8b9c93601 [InstSimplify] add test for select of vector constants; NFC 2020-01-17 16:39:55 -05:00
Sanjay Patel 3ae38d95e6 [InstSimplify] add test for select of FP constants; NFC 2020-01-17 16:39:55 -05:00
Sanjay Patel cfe2fab708 [InstSimplify] add tests for vector select; NFC 2020-01-14 08:41:06 -05:00
Sanjay Patel 26d2ace9e2 [InstSimplify] move tests for select from InstCombine; NFC
InstCombine has transforms that would enable these simplifications
in an indirect way, but those transforms are unsafe and likely to
be removed.
2020-01-13 09:13:21 -05:00
Sanjay Patel f53b38d12a [InstSimplify] select Cond, true, false --> Cond
This is step 1 of damage control assuming that we need to remove several
over-reaching folds for select-of-booleans because they can cause
miscompiles as shown in D72396.

The scalar case seems obviously safe:
https://rise4fun.com/Alive/jSj

And I don't think there's any danger for vectors either - if the
condition is poisoned, then the select must be poisoned too, so undef
elements don't make any difference.

Differential Revision: https://reviews.llvm.org/D72412
2020-01-09 09:04:20 -05:00