1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/cx/utils.h Mon Dec 27 16:51:10 2021 +0100
1.3 @@ -0,0 +1,120 @@
1.4 +/*
1.5 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
1.6 + *
1.7 + * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
1.8 + *
1.9 + * Redistribution and use in source and binary forms, with or without
1.10 + * modification, are permitted provided that the following conditions are met:
1.11 + *
1.12 + * 1. Redistributions of source code must retain the above copyright
1.13 + * notice, this list of conditions and the following disclaimer.
1.14 + *
1.15 + * 2. Redistributions in binary form must reproduce the above copyright
1.16 + * notice, this list of conditions and the following disclaimer in the
1.17 + * documentation and/or other materials provided with the distribution.
1.18 + *
1.19 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.20 + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.21 + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.22 + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
1.23 + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.24 + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.25 + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.26 + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.27 + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.28 + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.29 + * POSSIBILITY OF SUCH DAMAGE.
1.30 + */
1.31 +
1.32 +/**
1.33 + * \file utils.h
1.34 + *
1.35 + * \brief General purpose utility functions.
1.36 + *
1.37 + * \author Mike Becker
1.38 + * \author Olaf Wintermann
1.39 + * \version 3.0
1.40 + * \copyright 2-Clause BSD License
1.41 + */
1.42 +
1.43 +#ifndef UCX_UTILS_H
1.44 +#define UCX_UTILS_H
1.45 +
1.46 +#include "common.h"
1.47 +
1.48 +#ifdef __cplusplus
1.49 +extern "C" {
1.50 +#endif
1.51 +
1.52 +/* ----------------------
1.53 + * cx_szmul() definition.
1.54 + * ---------------------- */
1.55 +
1.56 +#if (__GNUC__ >= 5 || defined(__clang__)) && !defined(CX_NO_SZMUL_BUILTIN)
1.57 +#define CX_SZMUL_BUILTIN
1.58 +
1.59 +#if __WORDSIZE == 32
1.60 +/**
1.61 + * Alias for \c __builtin_umul_overflow.
1.62 + *
1.63 + * Performs a multiplication of size_t values and checks for overflow.
1.64 + *
1.65 + * @param a first operand
1.66 + * @param b second operand
1.67 + * @param result a pointer to a size_t, where the result should
1.68 + * be stored
1.69 + * @return zero, if no overflow occurred and the result is correct, non-zero
1.70 + * otherwise
1.71 + */
1.72 +#define cx_szmul(a, b, result) __builtin_umul_overflow(a, b, result)
1.73 +#else /* __WORDSIZE != 32 */
1.74 +/**
1.75 + * Alias for \c __builtin_umull_overflow.
1.76 + *
1.77 + * Performs a multiplication of size_t values and checks for overflow.
1.78 + *
1.79 + * @param a first operand
1.80 + * @param b second operand
1.81 + * @param result a pointer to a size_t, where the result should
1.82 + * be stored
1.83 + * @return zero, if no overflow occurred and the result is correct, non-zero
1.84 + * otherwise
1.85 + */
1.86 +#define cx_szmul(a, b, result) __builtin_umull_overflow(a, b, result)
1.87 +#endif /* __WORDSIZE */
1.88 +
1.89 +#else /* no GNUC or clang bultin */
1.90 +
1.91 +/**
1.92 + * Performs a multiplication of size_t values and checks for overflow.
1.93 + *
1.94 + * @param a first operand
1.95 + * @param b second operand
1.96 + * @param result a pointer to a size_t, where the result should
1.97 + * be stored
1.98 + * @return zero, if no overflow occurred and the result is correct, non-zero
1.99 + * otherwise
1.100 + */
1.101 +#define cx_szmul(a, b, result) cx_szmul_impl(a, b, result)
1.102 +
1.103 +/**
1.104 + * Performs a multiplication of size_t values and checks for overflow.
1.105 + *
1.106 + * This is a custom implementation in case there is no compiler builtin
1.107 + * available.
1.108 + *
1.109 + * @param a first operand
1.110 + * @param b second operand
1.111 + * @param result a pointer to a size_t where the result should be stored
1.112 + * @return zero, if no overflow occurred and the result is correct, non-zero
1.113 + * otherwise
1.114 + */
1.115 +int cx_szmul_impl(size_t a, size_t b, size_t *result);
1.116 +
1.117 +#endif
1.118 +
1.119 +#ifdef __cplusplus
1.120 +}
1.121 +#endif
1.122 +
1.123 +#endif /* UCX_UTILS_H */
