Index: lib/Sema/SemaCoroutine.cpp =================================================================== --- lib/Sema/SemaCoroutine.cpp +++ lib/Sema/SemaCoroutine.cpp @@ -1316,10 +1316,6 @@ if (Res.isInvalid()) return false; - if (GroType == FnRetType) { - GroDecl->setNRVOVariable(true); - } - S.AddInitializerToDecl(GroDecl, Res.get(), /*DirectInit=*/false); @@ -1343,6 +1339,8 @@ noteMemberDeclaredHere(S, ReturnValue, Fn); return false; } + if (cast(ReturnStmt.get())->getNRVOCandidate() == GroDecl) + GroDecl->setNRVOVariable(true); this->ReturnStmt = ReturnStmt.get(); return true; Index: test/CodeGenCoroutines/coro-alloc.cpp =================================================================== --- test/CodeGenCoroutines/coro-alloc.cpp +++ test/CodeGenCoroutines/coro-alloc.cpp @@ -173,6 +173,7 @@ // CHECK-LABEL: f4( extern "C" int f4(promise_on_alloc_failure_tag) { // CHECK: %[[RetVal:.+]] = alloca i32 + // CHECK: %[[Gro:.+]] = alloca i32 // CHECK: %[[ID:.+]] = call token @llvm.coro.id(i32 16 // CHECK: %[[SIZE:.+]] = call i64 @llvm.coro.size.i64() // CHECK: %[[MEM:.+]] = call i8* @_ZnwmRKSt9nothrow_t(i64 %[[SIZE]], %"struct.std::nothrow_t"* dereferenceable(1) @_ZStL7nothrow) @@ -186,7 +187,11 @@ // CHECK: [[OKBB]]: // CHECK: %[[OkRet:.+]] = call i32 @_ZNSt12experimental16coroutine_traitsIJi28promise_on_alloc_failure_tagEE12promise_type17get_return_objectEv( - // CHECK: store i32 %[[OkRet]], i32* %[[RetVal]] + // CHECK: store i32 %[[OkRet]], i32* %[[Gro]] + + // CHECK: %[[Tmp1:.*]] = load i32, i32* %[[Gro]] + // CHECK-NEXT: store i32 %[[Tmp1]], i32* %[[RetVal]] + // CHECK-NEXT: br label %[[RetBB]] // CHECK: [[RetBB]]: // CHECK: %[[LoadRet:.+]] = load i32, i32* %[[RetVal]], align 4 Index: test/CodeGenCoroutines/coro-gro-nrvo.cpp =================================================================== --- /dev/null +++ test/CodeGenCoroutines/coro-gro-nrvo.cpp @@ -0,0 +1,87 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fcoroutines-ts -std=c++14 -emit-llvm %s -o - -disable-llvm-passes | FileCheck %s + +#include "Inputs/coroutine.h" + +using namespace std::experimental; + +namespace std { + +struct nothrow_t {}; +constexpr nothrow_t nothrow = {}; + +} // end namespace std + +// Required when get_return_object_on_allocation_failure() is defined by +// the promise. +void* operator new(__SIZE_TYPE__ __sz, const std::nothrow_t&) noexcept; +void operator delete(void* __p, const std::nothrow_t&) noexcept; + + +template +struct promise_type { + RetObject get_return_object(); + suspend_always initial_suspend(); + suspend_never final_suspend(); + void return_void(); + static void unhandled_exception(); +}; + +struct coro { + using promise_type = promise_type; + coro(coro const&); + struct Impl; + Impl *impl; +}; + +// Verify that the NRVO is applied to the Gro object. +// CHECK-LABEL: define void @_Z1fi(%struct.coro* noalias sret %agg.result, i32) +coro f(int) { +// CHECK: %call = call i8* @_Znwm( +// CHECK-NEXT: br label %[[CoroInit:.*]] + +// CHECK: {{.*}}[[CoroInit]]: +// CHECK: store i1 false, i1* %gro.active +// CHECK-NEXT: call void @{{.*get_return_objectEv}}(%struct.coro* sret %agg.result +// CHECK-NEXT: store i1 true, i1* %gro.active + co_return; +} + + +template +struct promise_type_with_on_alloc_failure { + static RetObject get_return_object_on_allocation_failure(); + RetObject get_return_object(); + suspend_always initial_suspend(); + suspend_never final_suspend(); + void return_void(); + static void unhandled_exception(); +}; + +struct coro_two { + using promise_type = promise_type_with_on_alloc_failure; + coro_two(coro_two const&); + struct Impl; + Impl *impl; +}; + +// Verify that the NRVO is applied to the Gro object. +// CHECK-LABEL: define void @_Z1hi(%struct.coro_two* noalias sret %agg.result, i32) + coro_two h(int) { + +// CHECK: %call = call i8* @_ZnwmRKSt9nothrow_t +// CHECK-NEXT: %[[CheckNull:.*]] = icmp ne i8* %call, null +// CHECK-NEXT: br i1 %[[CheckNull]], label %[[InitOnSuccess:.*]], label %[[InitOnFailure:.*]] + +// CHECK: {{.*}}[[InitOnFailure]]: +// CHECK-NEXT: call void @{{.*get_return_object_on_allocation_failureEv}}(%struct.coro_two* sret %agg.result +// CHECK-NEXT: br label %[[RetLabel:.*]] + +// CHECK: {{.*}}[[InitOnSuccess]]: +// CHECK: store i1 false, i1* %gro.active +// CHECK-NEXT: call void @{{.*get_return_objectEv}}(%struct.coro_two* sret %agg.result +// CHECK-NEXT: store i1 true, i1* %gro.active + +// CHECK: [[RetLabel]]: +// CHECK-NEXT: ret void + co_return; +}