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| author | Stuart Hastings <stuart@apple.com> | 2011-05-14 05:55:10 +0000 |
|---|---|---|
| committer | Stuart Hastings <stuart@apple.com> | 2011-05-14 05:55:10 +0000 |
| commit | 66a82b966eaf2814dca4ee643d826aebc4d1be90 (patch) | |
| tree | 4ca8a9a45e7ee8ef9721abfe80a64a84216e911f /llvm/lib/Transforms | |
| parent | c9a5573ef1f3b6f9cbb495ad7559fbe770a2f168 (diff) | |
| download | bcm5719-llvm-66a82b966eaf2814dca4ee643d826aebc4d1be90.tar.gz bcm5719-llvm-66a82b966eaf2814dca4ee643d826aebc4d1be90.zip | |
Avoid combining GEPs that might overflow at runtime.
rdar://problem/9267970
Patch by Julien Lerouge!
llvm-svn: 131339
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index b6963c54999..ede659b0111 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -634,6 +634,7 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, if (AllZeros) return FoldGEPICmp(GEPLHS, GEPRHS->getOperand(0), Cond, I); + bool GEPsInBounds = GEPLHS->isInBounds() && GEPRHS->isInBounds(); if (GEPLHS->getNumOperands() == GEPRHS->getNumOperands()) { // If the GEPs only differ by one index, compare it. unsigned NumDifferences = 0; // Keep track of # differences. @@ -656,7 +657,7 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, ConstantInt::get(Type::getInt1Ty(I.getContext()), ICmpInst::isTrueWhenEqual(Cond))); - else if (NumDifferences == 1) { + else if (NumDifferences == 1 && GEPsInBounds) { Value *LHSV = GEPLHS->getOperand(DiffOperand); Value *RHSV = GEPRHS->getOperand(DiffOperand); // Make sure we do a signed comparison here. @@ -667,6 +668,7 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, // Only lower this if the icmp is the only user of the GEP or if we expect // the result to fold to a constant! if (TD && + GEPsInBounds && (isa<ConstantExpr>(GEPLHS) || GEPLHS->hasOneUse()) && (isa<ConstantExpr>(GEPRHS) || GEPRHS->hasOneUse())) { // ((gep Ptr, OFFSET1) cmp (gep Ptr, OFFSET2) ---> (OFFSET1 cmp OFFSET2) |
