Fix returned attr

Author: arsenm

llvm/test/tools/llvm-reduce/reduce-values-to-return-new-return-type.ll

@@ -153,3 +153,36 @@ define range(i32 8, 256) <2 x i32> @preserve_compatible_return_range(ptr %arg, <
   store i32 %load, ptr @gv
   ret <2 x i32> %arg1
 }
+
+; INTERESTING-LABEL: @drop_incompatible_returned_param_attr_0(
+
+; RESULT-LABEL: define i32 @drop_incompatible_returned_param_attr_0(ptr %arg, ptr %arg1) {
+; RESULT-NEXT: %load = load i32, ptr %arg
+; RESULT-NEXT: ret i32 %load
+define ptr @drop_incompatible_returned_param_attr_0(ptr returned %arg, ptr %arg1) {
+  %load = load i32, ptr %arg
+  store i32 %load, ptr @gv
+  ret ptr %arg
+}
+
+; INTERESTING-LABEL: @drop_incompatible_returned_param_attr_1(
+
+; RESULT-LABEL: define i32 @drop_incompatible_returned_param_attr_1(ptr %arg, ptr %arg1) {
+; RESULT-NEXT: %load = load i32, ptr %arg
+; RESULT-NEXT: ret i32 %load
+define ptr @drop_incompatible_returned_param_attr_1(ptr %arg, ptr returned %arg1) {
+  %load = load i32, ptr %arg
+  store i32 %load, ptr @gv
+  ret ptr %arg
+}
+
+; INTERESTING-LABEL: @drop_incompatible_returned_param_attr_2
+
+; RESULT-LABEL: define ptr @drop_incompatible_returned_param_attr_2(ptr %arg, ptr %arg1) {
+; RESULT-NEXT: %load = load ptr, ptr %arg
+; RESULT-NEXT: ret ptr %load
+define ptr @drop_incompatible_returned_param_attr_2(ptr %arg, ptr returned %arg1) {
+  %load = load ptr, ptr %arg
+  store ptr %load, ptr @gv
+  ret ptr %arg1
+}

llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.cpp

@@ -105,6 +105,10 @@ static void rewriteFuncWithReturnType(Function &OldF, Value *NewRetValue) {
     OldF.removeRetAttrs(IncompatibleAttrs);
   }
 
+  // Now we need to remove any returned attributes from parameters.
+  for (Argument &A : OldF.args())
+    OldF.removeParamAttr(A.getArgNo(), Attribute::Returned);
+
   Function *NewF =
       Function::Create(NewFuncTy, OldF.getLinkage(), OldF.getAddressSpace(), "",
                        OldF.getParent());