diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/Transforms/MemCpyOpt/pr29105.ll | 38 |
2 files changed, 41 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp index e77a8936bb7..27c37cd5289 100644 --- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -1108,8 +1108,10 @@ bool MemCpyOptPass::processMemSetMemCpyDependence(MemCpyInst *MemCpy, /// The \p MemCpy must have a Constant length. bool MemCpyOptPass::performMemCpyToMemSetOptzn(MemCpyInst *MemCpy, MemSetInst *MemSet) { + AliasAnalysis &AA = LookupAliasAnalysis(); + // This only makes sense on memcpy(..., memset(...), ...). - if (MemSet->getRawDest() != MemCpy->getRawSource()) + if (!AA.isMustAlias(MemSet->getRawDest(), MemCpy->getRawSource())) return false; ConstantInt *CopySize = cast<ConstantInt>(MemCpy->getLength()); diff --git a/llvm/test/Transforms/MemCpyOpt/pr29105.ll b/llvm/test/Transforms/MemCpyOpt/pr29105.ll new file mode 100644 index 00000000000..ad9f97e7a23 --- /dev/null +++ b/llvm/test/Transforms/MemCpyOpt/pr29105.ll @@ -0,0 +1,38 @@ +; RUN: opt -memcpyopt -instcombine -S %s | FileCheck %s +%Foo = type { [2048 x i64] } + +; CHECK-LABEL: @baz( +; CHECK-NOT: call void @llvm.memcpy +define void @baz() unnamed_addr #0 { +entry-block: + %x.sroa.0 = alloca [2048 x i64], align 8 + %tmp0 = alloca [2048 x i64], align 8 + %0 = bitcast [2048 x i64]* %tmp0 to i8* + %tmp2 = alloca %Foo, align 8 + %x.sroa.0.0..sroa_cast6 = bitcast [2048 x i64]* %x.sroa.0 to i8* + call void @llvm.lifetime.start(i64 16384, i8* %x.sroa.0.0..sroa_cast6) + call void @llvm.lifetime.start(i64 16384, i8* %0) + call void @llvm.memset.p0i8.i64(i8* %0, i8 0, i64 16384, i32 8, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %x.sroa.0.0..sroa_cast6, i8* %0, i64 16384, i32 8, i1 false) + call void @llvm.lifetime.end(i64 16384, i8* %0) + %1 = bitcast %Foo* %tmp2 to i8* + call void @llvm.lifetime.start(i64 16384, i8* %1) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %1, i8* %x.sroa.0.0..sroa_cast6, i64 16384, i32 8, i1 false) + call void @bar(%Foo* noalias nocapture nonnull dereferenceable(16384) %tmp2) + call void @llvm.lifetime.end(i64 16384, i8* %1) + call void @llvm.lifetime.end(i64 16384, i8* %x.sroa.0.0..sroa_cast6) + ret void +} + +declare void @llvm.lifetime.start(i64, i8* nocapture) #1 + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1) #1 + +declare void @llvm.lifetime.end(i64, i8* nocapture) #1 + +declare void @bar(%Foo* noalias nocapture readonly dereferenceable(16384)) unnamed_addr #0 + +declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i32, i1) #1 + +attributes #0 = { uwtable } +attributes #1 = { argmemonly nounwind } |
