[PATCH] D55371: Fix thunks returning memptrs via sret by emitting also scalar return values directly in sret slot (PR39901)

[Hans Wennborg via Phabricator via cfe-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL348569: Fix thunks returning memptrs via sret by emitting also scalar return values… (authored by hans, committed by ).

Changed prior to commit:
  https://reviews.llvm.org/D55371?vs=176971&id=177135#toc

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D55371/new/

https://reviews.llvm.org/D55371

Files:
  cfe/trunk/lib/CodeGen/CGVTables.cpp
  cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
  cfe/trunk/test/CodeGenCXX/thunk-returning-memptr.cpp


Index: cfe/trunk/test/CodeGenCXX/thunk-returning-memptr.cpp
===================================================================
--- cfe/trunk/test/CodeGenCXX/thunk-returning-memptr.cpp
+++ cfe/trunk/test/CodeGenCXX/thunk-returning-memptr.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -triple=i686 -emit-llvm -o - %s | FileCheck %s
+
+
+struct X;
+typedef void (X::*memptr)();
+
+struct A {
+  virtual memptr f();
+};
+
+struct B {
+  virtual memptr f();
+};
+
+struct C : A, B {
+  C();
+  memptr f() override __attribute__((noinline)) { return nullptr; };
+};
+
+C::C() {}
+
+// Make sure the member pointer is returned from the thunk via the return slot.
+// Because of the tail call, the return value cannot be copied into a local
+// alloca. (PR39901)
+
+// CHECK-LABEL: define linkonce_odr void @_ZThn4_N1C1fEv({ i32, i32 }* noalias sret %agg.result, %struct.C* %this)
+// CHECK: tail call void @_ZN1C1fEv({ i32, i32 }* sret %agg.result
Index: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
@@ -1073,9 +1073,8 @@
     // Count the implicit return.
     if (!endsWithReturn(D))
       ++NumReturnExprs;
-  } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
-             !hasScalarEvaluationKind(CurFnInfo->getReturnType())) {
-    // Indirect aggregate return; emit returned value directly into sret slot.
+  } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect) {
+    // Indirect return; emit returned value directly into sret slot.
     // This reduces code size, and affects correctness in C++.
     auto AI = CurFn->arg_begin();
     if (CurFnInfo->getReturnInfo().isSRetAfterThis())
Index: cfe/trunk/lib/CodeGen/CGVTables.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGVTables.cpp
+++ cfe/trunk/lib/CodeGen/CGVTables.cpp
@@ -350,8 +350,7 @@
                                   : FPT->getReturnType();
   ReturnValueSlot Slot;
   if (!ResultType->isVoidType() &&
-      CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
-      !hasScalarEvaluationKind(CurFnInfo->getReturnType()))
+      CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect)
     Slot = ReturnValueSlot(ReturnValue, ResultType.isVolatileQualified());
 
   // Now emit our call.


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