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author | Matt Arsenault <Matthew.Arsenault@amd.com> | 2014-06-09 19:20:29 +0000 |
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committer | Matt Arsenault <Matthew.Arsenault@amd.com> | 2014-06-09 19:20:29 +0000 |
commit | 8a0c2d17f5a26bde5e080abd88587aba76b6a325 (patch) | |
tree | ac269216ce2008e4aa5b89cf6aff4aefb3b2098c /lib | |
parent | 77b0b852fad6397db36a14c85dac8747d0fb9211 (diff) | |
download | llvm-8a0c2d17f5a26bde5e080abd88587aba76b6a325.tar.gz llvm-8a0c2d17f5a26bde5e080abd88587aba76b6a325.tar.bz2 llvm-8a0c2d17f5a26bde5e080abd88587aba76b6a325.tar.xz |
Look through addrspacecasts when turning ptr comparisons into
index comparisons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210488 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index d98f966f8c..639d8319e0 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -612,9 +612,10 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, if (ICmpInst::isSigned(Cond)) return nullptr; - // Look through bitcasts. - if (BitCastInst *BCI = dyn_cast<BitCastInst>(RHS)) - RHS = BCI->getOperand(0); + // Look through bitcasts and addrspacecasts. We do not however want to remove + // 0 GEPs. + if (!isa<GetElementPtrInst>(RHS)) + RHS = RHS->stripPointerCasts(); Value *PtrBase = GEPLHS->getOperand(0); if (DL && PtrBase == RHS && GEPLHS->isInBounds()) { @@ -655,9 +656,24 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, (GEPRHS->hasAllConstantIndices() || GEPRHS->hasOneUse()) && PtrBase->stripPointerCasts() == GEPRHS->getOperand(0)->stripPointerCasts()) { + Value *LOffset = EmitGEPOffset(GEPLHS); + Value *ROffset = EmitGEPOffset(GEPRHS); + + // If we looked through an addrspacecast between different sized address + // spaces, the LHS and RHS pointers are different sized + // integers. Truncate to the smaller one. + Type *LHSIndexTy = LOffset->getType(); + Type *RHSIndexTy = ROffset->getType(); + if (LHSIndexTy != RHSIndexTy) { + if (LHSIndexTy->getPrimitiveSizeInBits() < + RHSIndexTy->getPrimitiveSizeInBits()) { + ROffset = Builder->CreateTrunc(ROffset, LHSIndexTy); + } else + LOffset = Builder->CreateTrunc(LOffset, RHSIndexTy); + } + Value *Cmp = Builder->CreateICmp(ICmpInst::getSignedPredicate(Cond), - EmitGEPOffset(GEPLHS), - EmitGEPOffset(GEPRHS)); + LOffset, ROffset); return ReplaceInstUsesWith(I, Cmp); } |