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Merge pull request #904 from jbrodman/master

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Disable optimization to eliminate illegal results
This commit is contained in:
Dmitry Babokin
2014-11-13 16:13:15 -08:00
parent 2b956e9cad c565ec08ac
commit e834703bb7
1 changed files with 7 additions and 1 deletions
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8
opt.cpp
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@@ -1200,7 +1200,11 @@ InstructionSimplifyPass::simplifyBoolVec(llvm::Value *value) {
zext->getOperand(0)->getType() == LLVMTypes::Int1VectorType) zext->getOperand(0)->getType() == LLVMTypes::Int1VectorType)
return zext->getOperand(0); return zext->getOperand(0);
} }
/*
// This optimization has discernable benefit on the perf
// suite on latest LLVM versions.
// On 3.4+ (maybe even older), it can result in illegal
// operations, so it's being disabled.
llvm::ICmpInst *icmp = llvm::dyn_cast<llvm::ICmpInst>(value); llvm::ICmpInst *icmp = llvm::dyn_cast<llvm::ICmpInst>(value);
if (icmp != NULL) { if (icmp != NULL) {
// icmp(ne, {sext,zext}(foo), zeroinitializer) -> foo // icmp(ne, {sext,zext}(foo), zeroinitializer) -> foo
@@ -1216,7 +1220,9 @@ InstructionSimplifyPass::simplifyBoolVec(llvm::Value *value) {
return zext->getOperand(0); return zext->getOperand(0);
} }
} }
} }
*/
return NULL; return NULL;
} }