[OperandBundles] Treat "deopt" operand bundles specially

[oota-llvm.git] / test / Feature / OperandBundles / basic-aa-argmemonly.ll

diff --git a/test/Feature/OperandBundles/basic-aa-argmemonly.ll b/test/Feature/OperandBundles/basic-aa-argmemonly.ll
index 1f3b378868e7a0add301d1cf4dcb9507b6f74b87..aa9445886060217e93ad5ba8e4dab0e3630b364a 100644 (file)
--- a/test/Feature/OperandBundles/basic-aa-argmemonly.ll
+++ b/test/Feature/OperandBundles/basic-aa-argmemonly.ll
@@ -26,3 +26,26 @@ define i32 @test1(i32* %P, i32* noalias %P2) {
   ret i32 %diff
 ; CHECK: ret i32 0
 }
+
+define i32 @test2(i32* %P, i32* noalias %P2) {
+; Note: in this test we //can// GVN %v1 and %v2 into one value in theory.  Calls
+; with deopt operand bundles are not argmemonly because they *read* the entire
+; heap, but they don't write to any location in the heap if the callee does not
+; deoptimize the caller.  This fact, combined with the fact that
+; @argmemonly_function is, well, an argmemonly function, can be used to conclude
+; that %P is not written to at the callsite.  However LLVM currently cannot
+; describe the "does not write to non-args, and reads the entire heap" effect on
+; a callsite.
+
+; CHECK-LABEL: @test2(
+  %v1 = load i32, i32* %P
+; CHECK: %v1 = load i32, i32* %P
+  call void @argmemonly_function(i32* %P2) [ "deopt"() ]
+; CHECK: call void @argmemonly_function(
+  %v2 = load i32, i32* %P
+; CHECK: %v2 = load i32, i32* %P
+  %diff = sub i32 %v1, %v2
+; CHECK: %diff = sub i32 %v1, %v2
+  ret i32 %diff
+; CHECK: ret i32 %diff
+}