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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2002-2009. All Rights Reserved.
*
* 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.
*
* %CopyrightEnd%
*/
#include "eidef.h"
#if defined(HAVE_GMP_H) && defined(HAVE_LIBGMP)
#include <gmp.h>
#include "eidef.h"
#include "eiext.h"
#include "putget.h"
#include "ei_x_encode.h"
int ei_encode_bignum(char *buf, int *index, mpz_t obj)
{
char *s = buf + *index;
char *s0 = s;
size_t count;
int mpz_sign = mpz_sgn(obj);
/*
* FIXME we could code into ERL_[SMALL_]INTEGER_EXT but to make
* this code simple for now we always code into ERL_SMALL_BIG_EXT
*/
if (mpz_sign == 0) { /* Special case, bignum is zero */
if (!buf) s += 2;
else {
put8(s,ERL_SMALL_INTEGER_EXT);
put8(s,0);
}
} else {
if (!buf) {
int numb = 8; /* # bits in each external format limb */
s += (mpz_sizeinbase(obj, 2) + numb-1) / numb;
} else {
char *arityp;
put8(s,ERL_LARGE_BIG_EXT);
arityp = s; /* fill in later */
s += 4;
put8(s, mpz_sign == 1); /* save sign separately */
mpz_export(s, &count, -1, 1, 0, 0, obj);
s += count;
put32le(arityp, count);
}
}
*index += s-s0;
return 0;
}
int ei_x_encode_bignum(ei_x_buff* x, mpz_t n)
{
int i = x->index;
ei_encode_bignum(NULL, &i, n);
if (!x_fix_buff(x, i))
return -1;
return ei_encode_bignum(x->buff, &x->index, n);
}
#endif /* HAVE_GMP_H && HAVE_LIBGMP */
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