1 files changed, 119 insertions, 0 deletions
diff --git a/llvm/test/Analysis/MemorySSA/atomic-clobber.ll b/llvm/test/Analysis/MemorySSA/atomic-clobber.ll
new file mode 100644
index 00000000000..acd819a8935
--- /dev/null
+++ b/llvm/test/Analysis/MemorySSA/atomic-clobber.ll
@@ -0,0 +1,119 @@
+; 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
+;
+; Ensures that atomic loads count as MemoryDefs
+
+; CHECK-LABEL: define i32 @foo
+define i32 @foo(i32* %a, i32* %b) {
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: store i32 4
+  store i32 4, i32* %a, align 4
+; CHECK: 2 = MemoryDef(1)
+; CHECK-NEXT: %1 = load atomic i32
+  %1 = load atomic i32, i32* %b acquire, align 4
+; CHECK: MemoryUse(2)
+; CHECK-NEXT: %2 = load i32
+  %2 = load i32, i32* %a, align 4
+  %3 = add i32 %1, %2
+  ret i32 %3
+}
+
+; CHECK-LABEL: define void @bar
+define void @bar(i32* %a) {
+; CHECK: MemoryUse(liveOnEntry)
+; CHECK-NEXT: load atomic i32, i32* %a unordered, align 4
+  load atomic i32, i32* %a unordered, align 4
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: load atomic i32, i32* %a monotonic, align 4
+  load atomic i32, i32* %a monotonic, align 4
+; CHECK: 2 = MemoryDef(1)
+; CHECK-NEXT: load atomic i32, i32* %a acquire, align 4
+  load atomic i32, i32* %a acquire, align 4
+; CHECK: 3 = MemoryDef(2)
+; CHECK-NEXT: load atomic i32, i32* %a seq_cst, align 4
+  load atomic i32, i32* %a seq_cst, align 4
+  ret void
+}
+
+; CHECK-LABEL: define void @baz
+define void @baz(i32* %a) {
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: %1 = load atomic i32
+  %1 = load atomic i32, i32* %a acquire, align 4
+; CHECK: MemoryUse(1)
+; CHECK-NEXT: %2 = load atomic i32, i32* %a unordered, align 4
+  %2 = load atomic i32, i32* %a unordered, align 4
+; CHECK: 2 = MemoryDef(1)
+; CHECK-NEXT: %3 = load atomic i32, i32* %a monotonic, align 4
+  %3 = load atomic i32, i32* %a monotonic, align 4
+  ret void
+}
+
+; CHECK-LABEL: define void @fences
+define void @fences(i32* %a) {
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: fence acquire
+  fence acquire
+; CHECK: MemoryUse(1)
+; CHECK-NEXT: %1 = load i32, i32* %a
+  %1 = load i32, i32* %a
+
+; CHECK: 2 = MemoryDef(1)
+; CHECK-NEXT: fence release
+  fence release
+; CHECK: MemoryUse(2)
+; CHECK-NEXT: %2 = load i32, i32* %a
+  %2 = load i32, i32* %a
+
+; CHECK: 3 = MemoryDef(2)
+; CHECK-NEXT: fence acq_rel
+  fence acq_rel
+; CHECK: MemoryUse(3)
+; CHECK-NEXT: %3 = load i32, i32* %a
+  %3 = load i32, i32* %a
+
+; CHECK: 4 = MemoryDef(3)
+; CHECK-NEXT: fence seq_cst
+  fence seq_cst
+; CHECK: MemoryUse(4)
+; CHECK-NEXT: %4 = load i32, i32* %a
+  %4 = load i32, i32* %a
+  ret void
+}
+
+; CHECK-LABEL: define void @seq_cst_clobber
+define void @seq_cst_clobber(i32* noalias %a, i32* noalias %b) {
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: %1 = load atomic i32, i32* %a monotonic, align 4
+  load atomic i32, i32* %a monotonic, align 4
+
+; CHECK: 2 = MemoryDef(1)
+; CHECK-NEXT: %2 = load atomic i32, i32* %a seq_cst, align 4
+  load atomic i32, i32* %a seq_cst, align 4
+
+; CHECK: 3 = MemoryDef(2)
+; CHECK-NEXT: load atomic i32, i32* %a monotonic, align 4
+  load atomic i32, i32* %a monotonic, align 4
+
+  ret void
+}
+
+; Ensure that AA hands us MRI_Mod on unreorderable atomic ops.
+;
+; This test is a bit implementation-specific. In particular, it depends on that
+; we pass cmpxchg-load queries to AA, without trying to reason about them on
+; our own.
+;
+; If AA gets more aggressive, we can find another way.
+;
+; CHECK-LABEL: define void @check_aa_is_sane
+define void @check_aa_is_sane(i32* noalias %a, i32* noalias %b) {
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT: cmpxchg i32* %a, i32 0, i32 1 acquire acquire
+  cmpxchg i32* %a, i32 0, i32 1 acquire acquire
+; CHECK: MemoryUse(1)
+; CHECK-NEXT: load i32, i32* %b, align 4
+  load i32, i32* %b, align 4
+
+  ret void
+}