1 files changed, 38 insertions, 0 deletions
diff --git a/test/Analysis/MemorySSA/load-invariant.ll b/test/Analysis/MemorySSA/load-invariant.ll
new file mode 100644
index 000000000000..defb74641eaa
--- /dev/null
+++ b/test/Analysis/MemorySSA/load-invariant.ll
@@ -0,0 +1,38 @@
+; RUN: opt -basicaa -print-memoryssa -verify-memoryssa -analyze < %s 2>&1 | FileCheck %s
+; RUN: opt -aa-pipeline=basic-aa -passes='print<memoryssa>' -verify-memoryssa -disable-output < %s 2>&1 | FileCheck %s
+;
+; Invariant loads should be considered live on entry, because, once the
+; location is known to be dereferenceable, the value can never change.
+
+@g = external global i32
+
+declare void @clobberAllTheThings()
+
+; CHECK-LABEL: define i32 @foo
+define i32 @foo() {
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: call void @clobberAllTheThings()
+  call void @clobberAllTheThings()
+; CHECK: MemoryUse(liveOnEntry)
+; CHECK-NEXT: %1 = load i32
+  %1 = load i32, i32* @g, align 4, !invariant.load !0
+  ret i32 %1
+}
+
+; CHECK-LABEL: define i32 @bar
+define i32 @bar(i32* %a) {
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: call void @clobberAllTheThings()
+  call void @clobberAllTheThings()
+
+; CHECK: 2 = MemoryDef(1)
+; CHECK-NEXT: %1 = load atomic i32
+  %1 = load atomic i32, i32* %a acquire, align 4, !invariant.load !0
+
+; CHECK: MemoryUse(2)
+; CHECK-NEXT: %2 = load i32
+  %2 = load i32, i32* %a, align 4
+  ret i32 %2
+}
+
+!0 = !{}