72 lines
1.7 KiB
C++
72 lines
1.7 KiB
C++
/*
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* Copyright 2016-present Facebook, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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#include <cmath>
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namespace folly {
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#ifndef __ANDROID__
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/**
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* Most platforms hopefully provide std::nextafter.
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*/
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/* using override */ using std::nextafter;
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#else // !__ANDROID__
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/**
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* On Android, std::nextafter isn't implemented. However, the C functions and
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* compiler builtins are still provided. Using the GCC builtin is actually
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* slightly faster, as they're constexpr and the use cases within folly are in
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* constexpr context.
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*/
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#if defined(__GNUC__) && !defined(__clang__)
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constexpr float nextafter(float x, float y) {
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return __builtin_nextafterf(x, y);
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}
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constexpr double nextafter(double x, double y) {
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return __builtin_nextafter(x, y);
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}
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constexpr long double nextafter(long double x, long double y) {
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return __builtin_nextafterl(x, y);
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}
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#else // __GNUC__
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inline float nextafter(float x, float y) {
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return ::nextafterf(x, y);
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}
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inline double nextafter(double x, double y) {
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return ::nextafter(x, y);
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}
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inline long double nextafter(long double x, long double y) {
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return ::nextafterl(x, y);
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}
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#endif // __GNUC__
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#endif // __ANDROID__
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} // namespace folly
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