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| author | David Majnemer <david.majnemer@gmail.com> | 2016-08-07 07:58:00 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2016-08-07 07:58:00 +0000 |
| commit | 4e4f4437c27744de40acb2f79e51a7617352d7b6 (patch) | |
| tree | c4db1dc1bec6de0ab1eb02bda9434f502380142e | |
| parent | 49841c38121941982a96c0f635cdc3b71d4f1800 (diff) | |
| download | bcm5719-llvm-4e4f4437c27744de40acb2f79e51a7617352d7b6.tar.gz bcm5719-llvm-4e4f4437c27744de40acb2f79e51a7617352d7b6.zip | |
[InstCombine] Infer inbounds on geps of allocas
llvm-svn: 277950
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstructionCombining.cpp | 19 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/getelementptr.ll | 6 |
2 files changed, 22 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index 7ffe34a3c26..006deb6b5ff 100644 --- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -1899,6 +1899,25 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { } } + if (!GEP.isInBounds()) { + unsigned PtrWidth = + DL.getPointerSizeInBits(PtrOp->getType()->getPointerAddressSpace()); + APInt BasePtrOffset(PtrWidth, 0); + Value *UnderlyingPtrOp = + PtrOp->stripAndAccumulateInBoundsConstantOffsets(DL, + BasePtrOffset); + if (auto *AI = dyn_cast<AllocaInst>(UnderlyingPtrOp)) { + if (GEP.accumulateConstantOffset(DL, BasePtrOffset) && + BasePtrOffset.isNonNegative()) { + APInt AllocSize(PtrWidth, DL.getTypeAllocSize(AI->getAllocatedType())); + if (BasePtrOffset.ule(AllocSize)) { + return GetElementPtrInst::CreateInBounds( + PtrOp, makeArrayRef(Ops).slice(1), GEP.getName()); + } + } + } + } + return nullptr; } diff --git a/llvm/test/Transforms/InstCombine/getelementptr.ll b/llvm/test/Transforms/InstCombine/getelementptr.ll index a3c2beb7eb2..491fc355cba 100644 --- a/llvm/test/Transforms/InstCombine/getelementptr.ll +++ b/llvm/test/Transforms/InstCombine/getelementptr.ll @@ -367,7 +367,7 @@ define i32 @test21() { %rval = load i32, i32* %pbobel ret i32 %rval ; CHECK-LABEL: @test21( -; CHECK: getelementptr %intstruct, %intstruct* %pbob1, i64 0, i32 0 +; CHECK: getelementptr inbounds %intstruct, %intstruct* %pbob1, i64 0, i32 0 } @@ -541,8 +541,8 @@ define i8* @test32(i8* %v) { %G = load i8*, i8** %F ret i8* %G ; CHECK-LABEL: @test32( -; CHECK: %D = getelementptr [4 x i8*], [4 x i8*]* %A, i64 0, i64 1 -; CHECK: %F = getelementptr [4 x i8*], [4 x i8*]* %A, i64 0, i64 2 +; CHECK: %D = getelementptr inbounds [4 x i8*], [4 x i8*]* %A, i64 0, i64 1 +; CHECK: %F = getelementptr inbounds [4 x i8*], [4 x i8*]* %A, i64 0, i64 2 } ; PR3290 |
