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/* -*- Mode: C++; tab-width: 2; 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/. */
/* mfbt maths algorithms. */
#ifndef mozilla_MathAlgorithms_h_
#define mozilla_MathAlgorithms_h_
#include "mozilla/Assertions.h"
namespace mozilla {
// Greatest Common Divisor
template<typename IntegerType>
MOZ_ALWAYS_INLINE IntegerType
EuclidGCD(IntegerType a, IntegerType b)
{
// Euclid's algorithm; O(N) in the worst case. (There are better
// ways, but we don't need them for the current use of this algo.)
MOZ_ASSERT(a > 0);
MOZ_ASSERT(b > 0);
while (a != b) {
if (a > b) {
a = a - b;
} else {
b = b - a;
}
}
return a;
}
// Least Common Multiple
template<typename IntegerType>
MOZ_ALWAYS_INLINE IntegerType
EuclidLCM(IntegerType a, IntegerType b)
{
// Divide first to reduce overflow risk.
return (a / EuclidGCD(a, b)) * b;
}
} /* namespace mozilla */
#endif /* mozilla_MathAlgorithms_h_ */
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