61 lines
1.8 KiB
C++
61 lines
1.8 KiB
C++
/*
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* Copyright 2019 The WebRTC Project Authors. All rights reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef RTC_BASE_NUMERICS_DIVIDE_ROUND_H_
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#define RTC_BASE_NUMERICS_DIVIDE_ROUND_H_
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#include <type_traits>
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#include "rtc_base/checks.h"
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#include "rtc_base/numerics/safe_compare.h"
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namespace webrtc {
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template <typename Dividend, typename Divisor>
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inline auto constexpr DivideRoundUp(Dividend dividend, Divisor divisor) {
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static_assert(std::is_integral<Dividend>(), "");
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static_assert(std::is_integral<Divisor>(), "");
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RTC_DCHECK_GE(dividend, 0);
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RTC_DCHECK_GT(divisor, 0);
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auto quotient = dividend / divisor;
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auto remainder = dividend % divisor;
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return quotient + (remainder > 0 ? 1 : 0);
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}
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template <typename Dividend, typename Divisor>
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inline auto constexpr DivideRoundToNearest(Dividend dividend, Divisor divisor) {
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static_assert(std::is_integral<Dividend>(), "");
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static_assert(std::is_integral<Divisor>(), "");
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RTC_DCHECK_GT(divisor, 0);
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if (dividend < Dividend{0}) {
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auto half_of_divisor = divisor / 2;
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auto quotient = dividend / divisor;
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auto remainder = dividend % divisor;
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if (rtc::SafeGt(-remainder, half_of_divisor)) {
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--quotient;
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}
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return quotient;
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}
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auto half_of_divisor = (divisor - 1) / 2;
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auto quotient = dividend / divisor;
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auto remainder = dividend % divisor;
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if (rtc::SafeGt(remainder, half_of_divisor)) {
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++quotient;
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}
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return quotient;
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}
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} // namespace webrtc
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#endif // RTC_BASE_NUMERICS_DIVIDE_ROUND_H_
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