Make memcpyopt TBAA-aware.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121944 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 23 insertions, 0 deletions

diff --git a/test/Analysis/TypeBasedAliasAnalysis/memcpyopt.ll b/test/Analysis/TypeBasedAliasAnalysis/memcpyopt.ll
new file mode 100644
index 0000000000..c2407dfd4c
--- /dev/null
+++ b/test/Analysis/TypeBasedAliasAnalysis/memcpyopt.ll
@@ -0,0 +1,23 @@
+; RUN: opt -S -tbaa -basicaa -memcpyopt -instcombine < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64"
+
+; The second memcpy is redundant and can be deleted. There's an intervening store, but
+; it has a TBAA tag which declares that it is unrelated.
+
+; CHECK: @foo
+; CHECK-NEXT: tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %p, i8* %q, i64 16, i32 1, i1 false), !tbaa !0
+; CHECK-NEXT: store i8 2, i8* %s, align 1, !tbaa !2
+; CHECK-NEXT: ret void
+define void @foo(i8* nocapture %p, i8* nocapture %q, i8* nocapture %s) nounwind {
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %p, i8* %q, i64 16, i32 1, i1 false), !tbaa !2
+  store i8 2, i8* %s, align 1, !tbaa !1
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %q, i8* %p, i64 16, i32 1, i1 false), !tbaa !2
+  ret void
+}
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
+
+!0 = metadata !{metadata !"tbaa root", null}
+!1 = metadata !{metadata !"A", metadata !0}
+!2 = metadata !{metadata !"B", metadata !0}