forked from OSchip/llvm-project
146 lines
5.0 KiB
C++
146 lines
5.0 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is dual licensed under the MIT and the University of Illinois Open
|
|
// Source Licenses. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// UNSUPPORTED: c++98, c++03, c++11, c++14
|
|
|
|
// <numeric>
|
|
|
|
// template<class _M, class _N>
|
|
// constexpr common_type_t<_M,_N> gcd(_M __m, _N __n)
|
|
|
|
#include <numeric>
|
|
#include <cassert>
|
|
#include <climits>
|
|
#include <cstdint>
|
|
#include <cstdlib> // for rand()
|
|
#include <type_traits>
|
|
|
|
constexpr struct {
|
|
int x;
|
|
int y;
|
|
int expect;
|
|
} Cases[] = {
|
|
{0, 0, 0},
|
|
{1, 0, 1},
|
|
{0, 1, 1},
|
|
{1, 1, 1},
|
|
{2, 3, 1},
|
|
{2, 4, 2},
|
|
{36, 17, 1},
|
|
{36, 18, 18}
|
|
};
|
|
|
|
|
|
template <typename Input1, typename Input2, typename Output>
|
|
constexpr bool test0(int in1, int in2, int out)
|
|
{
|
|
auto value1 = static_cast<Input1>(in1);
|
|
auto value2 = static_cast<Input2>(in2);
|
|
static_assert(std::is_same_v<Output, decltype(std::gcd(value1, value2))>, "");
|
|
static_assert(std::is_same_v<Output, decltype(std::gcd(value2, value1))>, "");
|
|
assert(static_cast<Output>(out) == std::gcd(value1, value2));
|
|
return true;
|
|
}
|
|
|
|
|
|
template <typename Input1, typename Input2 = Input1>
|
|
constexpr bool do_test(int = 0)
|
|
{
|
|
using S1 = std::make_signed_t<Input1>;
|
|
using S2 = std::make_signed_t<Input2>;
|
|
using U1 = std::make_unsigned_t<Input1>;
|
|
using U2 = std::make_unsigned_t<Input2>;
|
|
bool accumulate = true;
|
|
for (auto TC : Cases) {
|
|
{ // Test with two signed types
|
|
using Output = std::common_type_t<S1, S2>;
|
|
accumulate &= test0<S1, S2, Output>(TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<S1, S2, Output>(-TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<S1, S2, Output>(TC.x, -TC.y, TC.expect);
|
|
accumulate &= test0<S1, S2, Output>(-TC.x, -TC.y, TC.expect);
|
|
accumulate &= test0<S2, S1, Output>(TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<S2, S1, Output>(-TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<S2, S1, Output>(TC.x, -TC.y, TC.expect);
|
|
accumulate &= test0<S2, S1, Output>(-TC.x, -TC.y, TC.expect);
|
|
}
|
|
{ // test with two unsigned types
|
|
using Output = std::common_type_t<U1, U2>;
|
|
accumulate &= test0<U1, U2, Output>(TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<U2, U1, Output>(TC.x, TC.y, TC.expect);
|
|
}
|
|
{ // Test with mixed signs
|
|
using Output = std::common_type_t<S1, U2>;
|
|
accumulate &= test0<S1, U2, Output>(TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<U2, S1, Output>(TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<S1, U2, Output>(-TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<U2, S1, Output>(TC.x, -TC.y, TC.expect);
|
|
}
|
|
{ // Test with mixed signs
|
|
using Output = std::common_type_t<S2, U1>;
|
|
accumulate &= test0<S2, U1, Output>(TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<U1, S2, Output>(TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<S2, U1, Output>(-TC.x, TC.y, TC.expect);
|
|
accumulate &= test0<U1, S2, Output>(TC.x, -TC.y, TC.expect);
|
|
}
|
|
}
|
|
return accumulate;
|
|
}
|
|
|
|
int main()
|
|
{
|
|
auto non_cce = std::rand(); // a value that can't possibly be constexpr
|
|
|
|
static_assert(do_test<signed char>(), "");
|
|
static_assert(do_test<short>(), "");
|
|
static_assert(do_test<int>(), "");
|
|
static_assert(do_test<long>(), "");
|
|
static_assert(do_test<long long>(), "");
|
|
|
|
assert(do_test<signed char>(non_cce));
|
|
assert(do_test<short>(non_cce));
|
|
assert(do_test<int>(non_cce));
|
|
assert(do_test<long>(non_cce));
|
|
assert(do_test<long long>(non_cce));
|
|
|
|
static_assert(do_test<std::int8_t>(), "");
|
|
static_assert(do_test<std::int16_t>(), "");
|
|
static_assert(do_test<std::int32_t>(), "");
|
|
static_assert(do_test<std::int64_t>(), "");
|
|
|
|
assert(do_test<std::int8_t>(non_cce));
|
|
assert(do_test<std::int16_t>(non_cce));
|
|
assert(do_test<std::int32_t>(non_cce));
|
|
assert(do_test<std::int64_t>(non_cce));
|
|
|
|
static_assert(do_test<signed char, int>(), "");
|
|
static_assert(do_test<int, signed char>(), "");
|
|
static_assert(do_test<short, int>(), "");
|
|
static_assert(do_test<int, short>(), "");
|
|
static_assert(do_test<int, long>(), "");
|
|
static_assert(do_test<long, int>(), "");
|
|
static_assert(do_test<int, long long>(), "");
|
|
static_assert(do_test<long long, int>(), "");
|
|
|
|
assert((do_test<signed char, int>(non_cce)));
|
|
assert((do_test<int, signed char>(non_cce)));
|
|
assert((do_test<short, int>(non_cce)));
|
|
assert((do_test<int, short>(non_cce)));
|
|
assert((do_test<int, long>(non_cce)));
|
|
assert((do_test<long, int>(non_cce)));
|
|
assert((do_test<int, long long>(non_cce)));
|
|
assert((do_test<long long, int>(non_cce)));
|
|
|
|
// LWG#2837
|
|
{
|
|
auto res = std::gcd(static_cast<std::int64_t>(1234), INT32_MIN);
|
|
static_assert(std::is_same_v<decltype(res), std::int64_t>, "");
|
|
assert(res == 2);
|
|
}
|
|
}
|