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//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// <numeric>
// template <class _Float>
// _Tp midpoint(_Float __a, _Float __b) noexcept
//
#include <numeric>
#include <cassert>
#include "test_macros.h"
#include "fp_compare.h"
// Totally arbitrary picks for precision
template <typename T>
constexpr T fp_error_pct();
template <>
constexpr float fp_error_pct<float>() { return 1.0e-4f; }
template <>
constexpr double fp_error_pct<double>() { return 1.0e-12; }
template <>
constexpr long double fp_error_pct<long double>() { return 1.0e-13l; }
template <typename T>
void fp_test()
{
ASSERT_SAME_TYPE(T, decltype(std::midpoint(T(), T())));
ASSERT_NOEXCEPT( std::midpoint(T(), T()));
constexpr T maxV = std::numeric_limits<T>::max();
constexpr T minV = std::numeric_limits<T>::min();
// Things that can be compared exactly
static_assert((std::midpoint(T(0), T(0)) == T(0)), "");
static_assert((std::midpoint(T(2), T(4)) == T(3)), "");
static_assert((std::midpoint(T(4), T(2)) == T(3)), "");
static_assert((std::midpoint(T(3), T(4)) == T(3.5)), "");
static_assert((std::midpoint(T(0), T(0.4)) == T(0.2)), "");
// Things that can't be compared exactly
constexpr T pct = fp_error_pct<T>();
assert((fptest_close_pct(std::midpoint(T( 1.3), T(11.4)), T( 6.35), pct)));
assert((fptest_close_pct(std::midpoint(T(11.33), T(31.45)), T(21.39), pct)));
assert((fptest_close_pct(std::midpoint(T(-1.3), T(11.4)), T( 5.05), pct)));
assert((fptest_close_pct(std::midpoint(T(11.4), T(-1.3)), T( 5.05), pct)));
assert((fptest_close_pct(std::midpoint(T(0.1), T(0.4)), T(0.25), pct)));
assert((fptest_close_pct(std::midpoint(T(11.2345), T(14.5432)), T(12.88885), pct)));
// From e to pi
assert((fptest_close_pct(std::midpoint(T(2.71828182845904523536028747135266249775724709369995),
T(3.14159265358979323846264338327950288419716939937510)),
T(2.92993724102441923691146542731608269097720824653752), pct)));
assert((fptest_close_pct(std::midpoint(maxV, T(0)), maxV/2, pct)));
assert((fptest_close_pct(std::midpoint(T(0), maxV), maxV/2, pct)));
assert((fptest_close_pct(std::midpoint(minV, T(0)), minV/2, pct)));
assert((fptest_close_pct(std::midpoint(T(0), minV), minV/2, pct)));
assert((fptest_close_pct(std::midpoint(maxV, maxV), maxV, pct)));
assert((fptest_close_pct(std::midpoint(minV, minV), minV, pct)));
assert((fptest_close_pct(std::midpoint(maxV, minV), maxV/2, pct)));
assert((fptest_close_pct(std::midpoint(minV, maxV), maxV/2, pct)));
// Near the min and the max
assert((fptest_close_pct(std::midpoint(maxV*T(0.75), maxV*T(0.50)), maxV*T(0.625), pct)));
assert((fptest_close_pct(std::midpoint(maxV*T(0.50), maxV*T(0.75)), maxV*T(0.625), pct)));
assert((fptest_close_pct(std::midpoint(minV*T(2), minV*T(8)), minV*T(5), pct)));
// Big numbers of different signs
assert((fptest_close_pct(std::midpoint(maxV*T( 0.75), maxV*T(-0.5)), maxV*T( 0.125), pct)));
assert((fptest_close_pct(std::midpoint(maxV*T(-0.75), maxV*T( 0.5)), maxV*T(-0.125), pct)));
// Denormalized values
// TODO
// Check two values "close to each other"
T d1 = T(3.14);
T d0 = std::nextafter(d1, T(2));
T d2 = std::nextafter(d1, T(5));
assert(d0 < d1); // sanity checking
assert(d1 < d2); // sanity checking
#if defined(__PPC__) && __LONG_DOUBLE_128__ && !(defined(__LONG_DOUBLE_IEEE128__) && __LONG_DOUBLE_IEEE128__)
// For 128 bit long double implemented as 2 doubles on PowerPC,
// nextafterl() of libm gives imprecise results which fails the
// midpoint() tests below. So skip the test for this case.
if constexpr (sizeof(T) != 16)
#endif
{
// Since there's nothing in between, the midpoint has to be one or the other
T res;
res = std::midpoint(d0, d1);
assert(res == d0 || res == d1);
assert(d0 <= res);
assert(res <= d1);
res = std::midpoint(d1, d0);
assert(res == d0 || res == d1);
assert(d0 <= res);
assert(res <= d1);
res = std::midpoint(d1, d2);
assert(res == d1 || res == d2);
assert(d1 <= res);
assert(res <= d2);
res = std::midpoint(d2, d1);
assert(res == d1 || res == d2);
assert(d1 <= res);
assert(res <= d2);
}
}
int main (int, char**)
{
fp_test<float>();
fp_test<double>();
fp_test<long double>();
return 0;
}
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