Commit Graph

14 Commits

Author SHA1 Message Date
Juneyoung Lee 9f074214b7 [ValueTracking] Instruction::isBinaryOp should be used for constexprs
This is a simple patch that makes canCreateUndefOrPoison use
Instruction::isBinaryOp because BinaryOperator inherits Instruction.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D84596
2020-07-26 21:48:51 +09:00
Juneyoung Lee 02dadab1b4 NFC; add an example that subtracts pointers to two global vars 2020-07-26 20:47:33 +09:00
Juneyoung Lee ace0bf7490 [ValueTracking] Fix incorrect handling of canCreateUndefOrPoison
.. in isGuaranteedNotToBeUndefOrPoison.

This caused early exit of isGuaranteedNotToBeUndefOrPoison, making it return
imprecise result.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D84251
2020-07-22 09:31:16 +09:00
Juneyoung Lee 30201d3b61 [ValueTracking] Let isGuaranteedNotToBeUndefOrPoison use canCreateUndefOrPoison
This patch adds support more operations.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D83926
2020-07-20 09:21:39 +09:00
Juneyoung Lee f5677fe700 [ValueTracking] Let isGuaranteedNotToBeUndefOrPoison look into more constants/instructions
Summary:
This patch helps isGuaranteedNotToBeUndefOrPoison look into more constants and instructions (bitcast/alloca/gep/fcmp).

To deal with bitcast, Depth is added to isGuaranteedNotToBeUndefOrPoison.

This patch is splitted from https://reviews.llvm.org/D75808.

Checked with Alive2

Reviewers: reames, jdoerfert

Reviewed By: jdoerfert

Subscribers: sanwou01, spatel, llvm-commits, hiraditya

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76010
2020-04-25 23:29:54 +09:00
Sanjay Patel cf30aafa2d [Analysis] recognize the 'null' pointer constant as not poison
Differential Revision: https://reviews.llvm.org/D78575
2020-04-21 14:23:06 -04:00
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
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
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
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