diff options
| author | Benjamin Kramer <benny.kra@googlemail.com> | 2011-01-06 14:22:52 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2011-01-06 14:22:52 +0000 |
| commit | 8143a84c46b8d2fb58eddb46d84dd5d44d03cb6c (patch) | |
| tree | 597092e9f340fae3b7c8e2d2c08dfb04f7801bd5 | |
| parent | 7d9f51f4b5e594c9c72717888a68c0c8a2f1267b (diff) | |
InstCombine: Turn _chk functions into the "unsafe" variant if length and max langth are equal.
This happens when we take the (non-constant) length from a malloc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122961 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCalls.cpp | 2 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/objsize.ll | 11 |
2 files changed, 13 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp index 603a01075a..ecd2243c35 100644 --- a/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -722,6 +722,8 @@ protected: NewInstruction = IC->ReplaceInstUsesWith(*CI, With); } bool isFoldable(unsigned SizeCIOp, unsigned SizeArgOp, bool isString) const { + if (CI->getArgOperand(SizeCIOp) == CI->getArgOperand(SizeArgOp)) + return true; if (ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getArgOperand(SizeCIOp))) { if (SizeCI->isAllOnesValue()) diff --git a/test/Transforms/InstCombine/objsize.ll b/test/Transforms/InstCombine/objsize.ll index 9950e5f4cc..4154ea0afb 100644 --- a/test/Transforms/InstCombine/objsize.ll +++ b/test/Transforms/InstCombine/objsize.ll @@ -176,3 +176,14 @@ define i32 @test9(i32 %x) { ; CHECK-NOT: ret i32 %x ret i32 %objsize } + +define i8* @test10(i32 %x) { +; CHECK: @test10 + %alloc = call noalias i8* @malloc(i32 %x) nounwind + %objsize = call i32 @llvm.objectsize.i32(i8* %alloc, i1 false) nounwind readonly + tail call i8* @__memset_chk(i8* %alloc, i32 0, i32 %x, i32 %objsize) nounwind +; CHECK-NOT: @llvm.objectsize +; CHECK: @llvm.memset + ret i8* %alloc +; CHECK: ret i8* +} |