universe@483: /*
universe@483:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@483:  *
universe@483:  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
universe@483:  *
universe@483:  * Redistribution and use in source and binary forms, with or without
universe@483:  * modification, are permitted provided that the following conditions are met:
universe@483:  *
universe@483:  *   1. Redistributions of source code must retain the above copyright
universe@483:  *      notice, this list of conditions and the following disclaimer.
universe@483:  *
universe@483:  *   2. Redistributions in binary form must reproduce the above copyright
universe@483:  *      notice, this list of conditions and the following disclaimer in the
universe@483:  *      documentation and/or other materials provided with the distribution.
universe@483:  *
universe@483:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@483:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@483:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@483:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@483:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@483:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@483:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@483:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@483:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@483:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@483:  * POSSIBILITY OF SUCH DAMAGE.
universe@483:  */
universe@483: 
universe@483: /**
universe@483:  * \file utils.h
universe@483:  *
universe@483:  * \brief General purpose utility functions.
universe@483:  *
universe@483:  * \author Mike Becker
universe@483:  * \author Olaf Wintermann
universe@483:  * \version 3.0
universe@483:  * \copyright 2-Clause BSD License
universe@483:  */
universe@483: 
universe@483: #ifndef UCX_UTILS_H
universe@483: #define UCX_UTILS_H
universe@483: 
universe@483: #include "common.h"
universe@483: 
universe@483: #ifdef __cplusplus
universe@483: extern "C" {
universe@483: #endif
universe@483: 
universe@527: /**
universe@527:  * Convenience macro for a for loop that counts from zero to n-1.
universe@527:  */
universe@509: #define cx_for_n(varname, n) for (size_t varname = 0 ; (varname) < (n) ; (varname)++)
universe@509: 
universe@483: /* ----------------------
universe@483:  * cx_szmul() definition.
universe@483:  * ---------------------- */
universe@483: 
universe@483: #if (__GNUC__ >= 5 || defined(__clang__)) && !defined(CX_NO_SZMUL_BUILTIN)
universe@483: #define CX_SZMUL_BUILTIN
universe@483: 
universe@483: #if __WORDSIZE == 32
universe@483: /**
universe@483:  * Alias for \c __builtin_umul_overflow.
universe@483:  *
universe@483:  * Performs a multiplication of size_t values and checks for overflow.
universe@483:  *
universe@483:  * @param a first operand
universe@483:  * @param b second operand
universe@483:  * @param result a pointer to a size_t, where the result should
universe@483:  * be stored
universe@483:  * @return zero, if no overflow occurred and the result is correct, non-zero
universe@483:  * otherwise
universe@483:  */
universe@483: #define cx_szmul(a, b, result) __builtin_umul_overflow(a, b, result)
universe@483: #else /* __WORDSIZE != 32 */
universe@483: /**
universe@483:  * Alias for \c __builtin_umull_overflow.
universe@483:  *
universe@483:  * Performs a multiplication of size_t values and checks for overflow.
universe@483:  *
universe@483:  * @param a first operand
universe@483:  * @param b second operand
universe@483:  * @param result a pointer to a size_t, where the result should
universe@483:  * be stored
universe@483:  * @return zero, if no overflow occurred and the result is correct, non-zero
universe@483:  * otherwise
universe@483:  */
universe@483: #define cx_szmul(a, b, result) __builtin_umull_overflow(a, b, result)
universe@483: #endif /* __WORDSIZE */
universe@483: 
universe@483: #else /* no GNUC or clang bultin */
universe@483: 
universe@483: /**
universe@483:  * Performs a multiplication of size_t values and checks for overflow.
universe@483:   *
universe@483:  * @param a first operand
universe@483:  * @param b second operand
universe@483:  * @param result a pointer to a size_t, where the result should
universe@483:  * be stored
universe@483:  * @return zero, if no overflow occurred and the result is correct, non-zero
universe@483:  * otherwise
universe@483:  */
universe@483: #define cx_szmul(a, b, result) cx_szmul_impl(a, b, result)
universe@483: 
universe@483: /**
universe@483:  * Performs a multiplication of size_t values and checks for overflow.
universe@483:  *
universe@483:  * This is a custom implementation in case there is no compiler builtin
universe@483:  * available.
universe@483:  *
universe@483:  * @param a first operand
universe@483:  * @param b second operand
universe@483:  * @param result a pointer to a size_t where the result should be stored
universe@483:  * @return zero, if no overflow occurred and the result is correct, non-zero
universe@483:  * otherwise
universe@483:  */
universe@483: int cx_szmul_impl(size_t a, size_t b, size_t *result);
universe@483: 
universe@483: #endif
universe@483: 
universe@483: #ifdef __cplusplus
universe@483: }
universe@483: #endif
universe@483: 
universe@483: #endif /* UCX_UTILS_H */