1 files changed, 43 insertions, 0 deletions
diff --git a/llvm/test/Analysis/MemorySSA/no-disconnected.ll b/llvm/test/Analysis/MemorySSA/no-disconnected.ll
new file mode 100644
index 00000000000..d1dcb15893a
--- /dev/null
+++ b/llvm/test/Analysis/MemorySSA/no-disconnected.ll
@@ -0,0 +1,43 @@
+; 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
+;
+; This test ensures we don't end up with multiple reaching defs for a single
+; use/phi edge If we were to optimize defs, we would end up with 2=
+; MemoryDef(liveOnEntry) and 4 = MemoryDef(liveOnEntry) Both would mean both
+; 1,2, and 3,4 would reach the phi node.  Because the phi node can only have one
+; entry on each edge, it would choose 2, 4 and disconnect 1 and 3 completely
+; from the SSA graph, even though they are not dead
+
+define void @sink_store(i32 %index, i32* %foo, i32* %bar) {
+entry:
+  %cmp = trunc i32 %index to i1
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+; CHECK: 1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT:   store i32 %index, i32* %foo, align 4
+  store i32 %index, i32* %foo, align 4
+; CHECK: 2 = MemoryDef(1)
+; CHECK-NEXT:   store i32 %index, i32* %bar, align 4
+  store i32 %index, i32* %bar, align 4
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+; CHECK: 3 = MemoryDef(liveOnEntry)
+; CHECK-NEXT:   store i32 %index, i32* %foo, align 4
+  store i32 %index, i32* %foo, align 4
+; CHECK: 4 = MemoryDef(3)
+; CHECK-NEXT:   store i32 %index, i32* %bar, align 4
+  store i32 %index, i32* %bar, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.else, %if.then
+; CHECK: 5 = MemoryPhi({if.then,2},{if.else,4})
+; CHECK: MemoryUse(5)
+; CHECK-NEXT:   %c = load i32, i32* %foo
+  %c = load i32, i32* %foo
+; CHECK: MemoryUse(5)
+; CHECK-NEXT:   %d = load i32, i32* %bar
+  %d = load i32, i32* %bar
+  ret void
+}