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/*
* Copyright (c) 2008, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SAT_MATH_H
#define SAT_MATH_H 1
#include <limits.h>
/* Saturating addition: overflow yields UINT_MAX. */
static inline unsigned int
sat_add(unsigned int x, unsigned int y)
{
return x + y >= x ? x + y : UINT_MAX;
}
/* Saturating subtraction: underflow yields 0. */
static inline unsigned int
sat_sub(unsigned int x, unsigned int y)
{
return x >= y ? x - y : 0;
}
/* Saturating multiplication of "unsigned int"s: overflow yields UINT_MAX. */
#define SAT_MUL(X, Y) \
((Y) == 0 ? 0 \
: (X) <= UINT_MAX / (Y) ? (unsigned int) (X) * (unsigned int) (Y) \
: UINT_MAX)
static inline unsigned int
sat_mul(unsigned int x, unsigned int y)
{
return SAT_MUL(x, y);
}
#endif /* sat-math.h */
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