Index: lib/Transforms/Scalar/MemCpyOptimizer.cpp =================================================================== --- lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -750,6 +750,14 @@ // its dependence information by changing its parameter. MD->removeInstruction(C); + // Update AA metadata + unsigned KnownIDs[] = { + LLVMContext::MD_tbaa, + LLVMContext::MD_alias_scope, + LLVMContext::MD_noalias, + }; + combineMetadata(C, cpy, KnownIDs); + // Remove the memcpy. MD->removeInstruction(cpy); ++NumMemCpyInstr; Index: test/Transforms/MemCpyOpt/callslot_aa.ll =================================================================== --- /dev/null +++ test/Transforms/MemCpyOpt/callslot_aa.ll @@ -0,0 +1,22 @@ +; RUN: opt < %s -S -basicaa -memcpyopt | FileCheck %s +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" + +%T = type { i64, i64 } + +define void @test(i8* %src) { + %tmp = alloca i8 + %dst = alloca i8 +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 1, i32 8, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %tmp, i8* %src, i64 1, i32 8, i1 false), !noalias !2 + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %tmp, i64 1, i32 8, i1 false) + + ret void +} + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8*, i8*, i64, i32, i1) + +; Check that the noalias for "dst" was removed by checking that the metadata is gone +; CHECK-NOT: "dst" +!0 = !{!0} +!1 = distinct !{!1, !0, !"dst"} +!2 = distinct !{!1}