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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef MOZILLA_GFX_NUMERICTOOLS_H_
#define MOZILLA_GFX_NUMERICTOOLS_H_
namespace mozilla {
// XXX - Move these into mfbt/MathAlgorithms.h?
// Returns the largest multiple of aMultiplied that's <= x.
// Same as int32_t(floor(double(x) / aMultiplier)) * aMultiplier,
// but faster.
inline int32_t
RoundDownToMultiple(int32_t x, int32_t aMultiplier)
{
// We don't use float division + floor because that's hard for the compiler
// to optimize.
int mod = x % aMultiplier;
if (x > 0) {
return x - mod;
}
return mod ? x - aMultiplier - mod : x;
}
// Returns the smallest multiple of aMultiplied that's >= x.
// Same as int32_t(ceil(double(x) / aMultiplier)) * aMultiplier,
// but faster.
inline int32_t
RoundUpToMultiple(int32_t x, int32_t aMultiplier)
{
int mod = x % aMultiplier;
if (x > 0) {
return mod ? x + aMultiplier - mod : x;
}
return x - mod;
}
} // namespace mozilla
#endif /* MOZILLA_GFX_NUMERICTOOLS_H_ */
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