baeddde44d
This is needed anytime we need to clamp an arbitrary floating point value to an integer type. Thanks to Eric Fiselier for the patch. Differential Revision: https://reviews.llvm.org/D66836 git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@370891 91177308-0d34-0410-b5e6-96231b3b80d8 (cherry picked from commit c9ac8d533010d8915bcfdecab891fb451f71ce74) (cherry picked from commit 4561f55204960c0b3bc4594089ddcf56e5655cad) Bug: https://bugs.chromium.org/p/chromium/issues/detail?id=994957 Bug: http://b/139690488 Change-Id: Ibfa9f6465214466511e3d35b02eb3b77488050e7
91 lines
2.9 KiB
C++
91 lines
2.9 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// __clamp_to_integral<IntT>(RealT)
|
|
|
|
// Test the conversion function that truncates floating point types to the
|
|
// closest representable value for the specified integer type, or
|
|
// numeric_limits<IntT>::max()/min() if the value isn't representable.
|
|
|
|
#include <limits>
|
|
#include <cassert>
|
|
#include <cmath>
|
|
|
|
template <class IntT>
|
|
void test() {
|
|
typedef std::numeric_limits<IntT> Lim;
|
|
const bool MaxIsRepresentable = sizeof(IntT) < 8;
|
|
const bool IsSigned = std::is_signed<IntT>::value;
|
|
struct TestCase {
|
|
double Input;
|
|
IntT Expect;
|
|
bool IsRepresentable;
|
|
} TestCases[] = {
|
|
{0, 0, true},
|
|
{1, 1, true},
|
|
{IsSigned ? static_cast<IntT>(-1) : 0,
|
|
IsSigned ? static_cast<IntT>(-1) : 0, true},
|
|
{Lim::lowest(), Lim::lowest(), true},
|
|
{static_cast<double>(Lim::max()), Lim::max(), MaxIsRepresentable},
|
|
{static_cast<double>(Lim::max()) + 1, Lim::max(), false},
|
|
{static_cast<double>(Lim::max()) + 1024, Lim::max(), false},
|
|
{nextafter(static_cast<double>(Lim::max()), INFINITY), Lim::max(), false},
|
|
};
|
|
for (TestCase TC : TestCases) {
|
|
auto res = std::__clamp_to_integral<IntT>(TC.Input);
|
|
assert(res == TC.Expect);
|
|
if (TC.IsRepresentable) {
|
|
auto other = static_cast<IntT>(std::trunc(TC.Input));
|
|
assert(res == other);
|
|
} else
|
|
assert(res == Lim::min() || res == Lim::max());
|
|
}
|
|
}
|
|
|
|
template <class IntT>
|
|
void test_float() {
|
|
typedef std::numeric_limits<IntT> Lim;
|
|
const bool MaxIsRepresentable = sizeof(IntT) < 4;
|
|
((void)MaxIsRepresentable);
|
|
const bool IsSigned = std::is_signed<IntT>::value;
|
|
struct TestCase {
|
|
float Input;
|
|
IntT Expect;
|
|
bool IsRepresentable;
|
|
} TestCases[] = {
|
|
{0, 0, true},
|
|
{1, 1, true},
|
|
{IsSigned ? static_cast<IntT>(-1) : 0,
|
|
IsSigned ? static_cast<IntT>(-1) : 0, true},
|
|
{Lim::lowest(), Lim::lowest(), true},
|
|
{static_cast<float>(Lim::max()), Lim::max(), MaxIsRepresentable },
|
|
{nextafter(static_cast<float>(Lim::max()), INFINITY), Lim::max(), false},
|
|
};
|
|
for (TestCase TC : TestCases) {
|
|
auto res = std::__clamp_to_integral<IntT>(TC.Input);
|
|
assert(res == TC.Expect);
|
|
if (TC.IsRepresentable) {
|
|
auto other = static_cast<IntT>(std::trunc(TC.Input));
|
|
assert(res == other);
|
|
} else
|
|
assert(res == Lim::min() || res == Lim::max());
|
|
}
|
|
}
|
|
|
|
int main() {
|
|
test<short>();
|
|
test<unsigned short>();
|
|
test<int>();
|
|
test<unsigned>();
|
|
test<long long>();
|
|
test<unsigned long long>();
|
|
test_float<short>();
|
|
test_float<int>();
|
|
test_float<long long>();
|
|
}
|