forked from OSchip/llvm-project
e1b09caaaf
This is a fix for PR22723: https://llvm.org/bugs/show_bug.cgi?id=22723 My first attempt at this was to change what I thought was the root problem: xor (zext i1 X to i32), 1 --> zext (xor i1 X, true) to i32 ...but we create the opposite pattern in InstCombiner::visitZExt(), so infinite loop! My next idea was to fix the matchIfNot() implementation in PatternMatch, but that would mean potentially returning a different size for the match than what was input. I think this would require all users of m_Not to check the size of the returned match, so I abandoned that idea. I settled on just fixing the exact case presented in the PR. This patch does allow the 2 functions in PR22723 to compile identically (x86): bool test(bool x, bool y) { return !x | !y; } bool test(bool x, bool y) { return !x || !y; } ... andb %sil, %dil xorb $1, %dil movb %dil, %al retq Differential Revision: http://reviews.llvm.org/D12705 llvm-svn: 248634 |
||
|---|---|---|
| .. | ||
| CMakeLists.txt | ||
| InstCombineAddSub.cpp | ||
| InstCombineAndOrXor.cpp | ||
| InstCombineCalls.cpp | ||
| InstCombineCasts.cpp | ||
| InstCombineCompares.cpp | ||
| InstCombineInternal.h | ||
| InstCombineLoadStoreAlloca.cpp | ||
| InstCombineMulDivRem.cpp | ||
| InstCombinePHI.cpp | ||
| InstCombineSelect.cpp | ||
| InstCombineShifts.cpp | ||
| InstCombineSimplifyDemanded.cpp | ||
| InstCombineVectorOps.cpp | ||
| InstructionCombining.cpp | ||
| LLVMBuild.txt | ||
| Makefile | ||