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| author | David Bolvansky <david.bolvansky@gmail.com> | 2019-09-17 17:12:24 +0000 |
|---|---|---|
| committer | David Bolvansky <david.bolvansky@gmail.com> | 2019-09-17 17:12:24 +0000 |
| commit | 0c0de794f1affc7460eb90626b8483e4a0cbde6c (patch) | |
| tree | 0e1328714d7f42863a740348cd00e954fa3efe94 | |
| parent | 5abd6f46ae8ae1a8b0f52b60fb52e1ba444b3d9b (diff) | |
| download | bcm5719-llvm-0c0de794f1affc7460eb90626b8483e4a0cbde6c.tar.gz bcm5719-llvm-0c0de794f1affc7460eb90626b8483e4a0cbde6c.zip | |
Reland "[SLC] Preserve attrs for strncpy(x, "", y) -> memset(align 1 x, '\0', y)"
llvm-svn: 372142
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp | 5 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/strncpy-1.ll | 10 |
2 files changed, 14 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp index 217f929e9ad..a5e31f21166 100644 --- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -610,7 +610,10 @@ Value *LibCallSimplifier::optimizeStrNCpy(CallInst *CI, IRBuilder<> &B) { if (SrcLen == 0) { // strncpy(x, "", y) -> memset(align 1 x, '\0', y) - B.CreateMemSet(Dst, B.getInt8('\0'), Size, 1); + CallInst *NewCI = B.CreateMemSet(Dst, B.getInt8('\0'), Size, 1); + AttrBuilder ArgAttrs(CI->getAttributes().getParamAttributes(0)); + NewCI->setAttributes(NewCI->getAttributes().addParamAttributes( + CI->getContext(), 0, ArgAttrs)); return Dst; } diff --git a/llvm/test/Transforms/InstCombine/strncpy-1.ll b/llvm/test/Transforms/InstCombine/strncpy-1.ll index 38e8cfedba2..969358eb4d7 100644 --- a/llvm/test/Transforms/InstCombine/strncpy-1.ll +++ b/llvm/test/Transforms/InstCombine/strncpy-1.ll @@ -134,6 +134,16 @@ define i8* @test2(i8* %dst) { ret i8* %ret } +define i8* @test3(i8* %dst, i32 %n) { +; CHECK-LABEL: @test3( +; CHECK-NEXT: call void @llvm.memset.p0i8.i32(i8* noalias nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i32 5, i1 false) +; CHECK-NEXT: ret i8* [[DST]] +; + %src = getelementptr [1 x i8], [1 x i8]* @null, i32 0, i32 0 + %ret = call i8* @strncpy(i8* noalias nonnull %dst, i8* nonnull %src, i32 5); + ret i8* %ret +} + ; Check cases that shouldn't be simplified. define void @test_no_simplify1() { |
