diff options
Diffstat (limited to 'third_party/libwebrtc/rtc_base/numerics/divide_round.h')
-rw-r--r-- | third_party/libwebrtc/rtc_base/numerics/divide_round.h | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/numerics/divide_round.h b/third_party/libwebrtc/rtc_base/numerics/divide_round.h new file mode 100644 index 0000000000..90c67fca3c --- /dev/null +++ b/third_party/libwebrtc/rtc_base/numerics/divide_round.h @@ -0,0 +1,60 @@ +/* + * Copyright 2019 The WebRTC Project Authors. All rights reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#ifndef RTC_BASE_NUMERICS_DIVIDE_ROUND_H_ +#define RTC_BASE_NUMERICS_DIVIDE_ROUND_H_ + +#include <type_traits> + +#include "rtc_base/checks.h" +#include "rtc_base/numerics/safe_compare.h" + +namespace webrtc { + +template <typename Dividend, typename Divisor> +inline auto constexpr DivideRoundUp(Dividend dividend, Divisor divisor) { + static_assert(std::is_integral<Dividend>(), ""); + static_assert(std::is_integral<Divisor>(), ""); + RTC_DCHECK_GE(dividend, 0); + RTC_DCHECK_GT(divisor, 0); + + auto quotient = dividend / divisor; + auto remainder = dividend % divisor; + return quotient + (remainder > 0 ? 1 : 0); +} + +template <typename Dividend, typename Divisor> +inline auto constexpr DivideRoundToNearest(Dividend dividend, Divisor divisor) { + static_assert(std::is_integral<Dividend>(), ""); + static_assert(std::is_integral<Divisor>(), ""); + RTC_DCHECK_GT(divisor, 0); + + if (dividend < Dividend{0}) { + auto half_of_divisor = divisor / 2; + auto quotient = dividend / divisor; + auto remainder = dividend % divisor; + if (rtc::SafeGt(-remainder, half_of_divisor)) { + --quotient; + } + return quotient; + } + + auto half_of_divisor = (divisor - 1) / 2; + auto quotient = dividend / divisor; + auto remainder = dividend % divisor; + if (rtc::SafeGt(remainder, half_of_divisor)) { + ++quotient; + } + return quotient; +} + +} // namespace webrtc + +#endif // RTC_BASE_NUMERICS_DIVIDE_ROUND_H_ |