cryb-to/lib/mpi/cryb_mpi_grow.c
2017-04-06 19:51:47 +02:00

65 lines
2.2 KiB
C

/*
* Copyright (c) 2014-2016 Dag-Erling Smørgrav
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "cryb/impl.h"
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <cryb/endian.h>
#include <cryb/mpi.h>
#include "cryb_mpi_impl.h"
/*
* Grow the underlying storage to fit at least n bits
*/
int
mpi_grow(cryb_mpi *X, unsigned int n)
{
uint32_t *words;
size_t size;
if (X->words == NULL)
MPI_FAST_INIT(X);
size = (n + 31) / 32;
if (X->size >= size)
return (0);
size = RUP(size, CRYB_MPI_SWORDS);
if ((words = calloc(1, size * sizeof *words)) == NULL)
return (-1);
memcpy(words, X->words, X->size * sizeof *words);
memset(X->words, 0, X->size * sizeof *words);
if (X->words != X->swords)
free(X->words);
X->words = words;
X->size = size;
return (0);
}