--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/llvm/test/Feature/OperandBundles/dse.ll	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,62 @@
+; RUN: opt -S -dse < %s | FileCheck %s
+
+declare void @f()
+declare noalias i8* @malloc(i32) nounwind
+
+define void @test_0() {
+; CHECK-LABEL: @test_0(
+  %m = call i8* @malloc(i32 24)
+  tail call void @f() [ "unknown"(i8* %m) ]
+; CHECK: store i8 -19, i8* %m
+  store i8 -19, i8* %m
+  ret void
+}
+
+define i8* @test_1() {
+; CHECK-LABEL: @test_1(
+  %m = call i8* @malloc(i32 24)
+  tail call void @f() [ "unknown"(i8* %m) ]
+  store i8 -19, i8* %m
+  tail call void @f()
+  store i8 101, i8* %m
+
+; CHECK: tail call void @f() [ "unknown"(i8* %m) ]
+; CHECK: store i8 -19, i8* %m
+; CHECK: tail call void @f()
+; CHECK: store i8 101, i8* %m
+
+  ret i8* %m
+}
+
+define void @test_2() {
+; Since the deopt operand bundle does not escape %m (see caveat below), it is
+; legal to elide the final store that location.
+
+; CHECK-LABEL: @test_2(
+  %m = call i8* @malloc(i32 24)
+  tail call void @f() [ "deopt"(i8* %m) ]
+  store i8 -19, i8* %m
+  ret void
+
+; CHECK:  tail call void @f() [ "deopt"(i8* %m) ]
+; CHECK-NEXT:  ret void
+}
+
+define i8* @test_3() {
+; Since the deopt operand bundle does not escape %m (see caveat below), @f
+; cannot observe the stores to %m
+
+; CHECK-LABEL: @test_3(
+  %m = call i8* @malloc(i32 24)
+  tail call void @f() [ "deopt"(i8* %m) ]
+  store i8 -19, i8* %m
+  tail call void @f()
+  store i8 101, i8* %m
+  ret i8* %m
+}
+
+
+; Caveat: technically, %m can only escape if the calling function is deoptimized
+; at the call site (i.e. the call returns to the "deopt" continuation).  Since
+; the calling function body will be invalidated in that case, the calling
+; function can be optimized under the assumption that %m does not escape.