llvm-project/clang/test/CodeGenCoroutines/coro-elide.cpp

64 lines
1.7 KiB
C++

// This tests that the coroutine elide optimization could happen succesfully.
// RUN: %clang_cc1 -no-opaque-pointers -triple x86_64-unknown-linux-gnu -std=c++20 -O2 -emit-llvm %s -o - | FileCheck %s
#include "Inputs/coroutine.h"
struct Task {
struct promise_type {
struct FinalAwaiter {
bool await_ready() const noexcept { return false; }
template <typename PromiseType>
std::coroutine_handle<> await_suspend(std::coroutine_handle<PromiseType> h) noexcept {
if (!h)
return std::noop_coroutine();
return h.promise().continuation;
}
void await_resume() noexcept {}
};
Task get_return_object() noexcept {
return std::coroutine_handle<promise_type>::from_promise(*this);
}
std::suspend_always initial_suspend() noexcept { return {}; }
FinalAwaiter final_suspend() noexcept { return {}; }
void unhandled_exception() noexcept {}
void return_value(int x) noexcept {
_value = x;
}
std::coroutine_handle<> continuation;
int _value;
};
Task(std::coroutine_handle<promise_type> handle) : handle(handle) {}
~Task() {
if (handle)
handle.destroy();
}
struct Awaiter {
bool await_ready() const noexcept { return false; }
void await_suspend(std::coroutine_handle<void> continuation) noexcept {}
int await_resume() noexcept {
return 43;
}
};
auto operator co_await() {
return Awaiter{};
}
private:
std::coroutine_handle<promise_type> handle;
};
Task task0() {
co_return 43;
}
Task task1() {
co_return co_await task0();
}
// CHECK: %_Z5task1v.Frame = type {{.*}}%_Z5task0v.Frame
// CHECK-LABEL: define{{.*}} void @_Z5task1v.resume
// CHECK-NOT: call{{.*}}_Znwm