diff options
Diffstat (limited to 'vendor/gmp-6.3.0/mpz/export.c')
| -rw-r--r-- | vendor/gmp-6.3.0/mpz/export.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/mpz/export.c b/vendor/gmp-6.3.0/mpz/export.c new file mode 100644 index 0000000..2dacd69 --- /dev/null +++ b/vendor/gmp-6.3.0/mpz/export.c @@ -0,0 +1,189 @@ +/* mpz_export -- create word data from mpz. + +Copyright 2002, 2003, 2012 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +The GNU MP Library is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://www.gnu.org/licenses/. */ + +#include <stdio.h> /* for NULL */ +#include "gmp-impl.h" +#include "longlong.h" + + +#if HAVE_LIMB_BIG_ENDIAN +#define HOST_ENDIAN 1 +#endif +#if HAVE_LIMB_LITTLE_ENDIAN +#define HOST_ENDIAN (-1) +#endif +#ifndef HOST_ENDIAN +static const mp_limb_t endian_test = (CNST_LIMB(1) << (GMP_LIMB_BITS-7)) - 1; +#define HOST_ENDIAN (* (signed char *) &endian_test) +#endif + +void * +mpz_export (void *data, size_t *countp, int order, + size_t size, int endian, size_t nail, mpz_srcptr z) +{ + mp_size_t zsize; + mp_srcptr zp; + size_t count, dummy; + unsigned long numb; + unsigned align; + + ASSERT (order == 1 || order == -1); + ASSERT (endian == 1 || endian == 0 || endian == -1); + ASSERT (nail <= 8*size); + ASSERT (nail < 8*size || SIZ(z) == 0); /* nail < 8*size+(SIZ(z)==0) */ + + if (countp == NULL) + countp = &dummy; + + zsize = SIZ(z); + if (zsize == 0) + { + *countp = 0; + return data; + } + + zsize = ABS (zsize); + zp = PTR(z); + numb = 8*size - nail; + MPN_SIZEINBASE_2EXP (count, zp, zsize, numb); + *countp = count; + + if (data == NULL) + data = (*__gmp_allocate_func) (count*size); + + if (endian == 0) + endian = HOST_ENDIAN; + + align = ((char *) data - (char *) NULL) % sizeof (mp_limb_t); + + if (nail == GMP_NAIL_BITS) + { + if (size == sizeof (mp_limb_t) && align == 0) + { + if (order == -1 && endian == HOST_ENDIAN) + { + MPN_COPY ((mp_ptr) data, zp, (mp_size_t) count); + return data; + } + if (order == 1 && endian == HOST_ENDIAN) + { + MPN_REVERSE ((mp_ptr) data, zp, (mp_size_t) count); + return data; + } + + if (order == -1 && endian == -HOST_ENDIAN) + { + MPN_BSWAP ((mp_ptr) data, zp, (mp_size_t) count); + return data; + } + if (order == 1 && endian == -HOST_ENDIAN) + { + MPN_BSWAP_REVERSE ((mp_ptr) data, zp, (mp_size_t) count); + return data; + } + } + } + + { + mp_limb_t limb, wbitsmask; + size_t i, numb; + mp_size_t j, wbytes, woffset; + unsigned char *dp; + int lbits, wbits; + mp_srcptr zend; + + numb = size * 8 - nail; + + /* whole bytes per word */ + wbytes = numb / 8; + + /* possible partial byte */ + wbits = numb % 8; + wbitsmask = (CNST_LIMB(1) << wbits) - 1; + + /* offset to get to the next word */ + woffset = (endian >= 0 ? size : - (mp_size_t) size) + + (order < 0 ? size : - (mp_size_t) size); + + /* least significant byte */ + dp = (unsigned char *) data + + (order >= 0 ? (count-1)*size : 0) + (endian >= 0 ? size-1 : 0); + +#define EXTRACT(N, MASK) \ + do { \ + if (lbits >= (N)) \ + { \ + *dp = limb MASK; \ + limb >>= (N); \ + lbits -= (N); \ + } \ + else \ + { \ + mp_limb_t newlimb; \ + newlimb = (zp == zend ? 0 : *zp++); \ + *dp = (limb | (newlimb << lbits)) MASK; \ + limb = newlimb >> ((N)-lbits); \ + lbits += GMP_NUMB_BITS - (N); \ + } \ + } while (0) + + zend = zp + zsize; + lbits = 0; + limb = 0; + for (i = 0; i < count; i++) + { + for (j = 0; j < wbytes; j++) + { + EXTRACT (8, + 0); + dp -= endian; + } + if (wbits != 0) + { + EXTRACT (wbits, & wbitsmask); + dp -= endian; + j++; + } + for ( ; j < size; j++) + { + *dp = '\0'; + dp -= endian; + } + dp += woffset; + } + + ASSERT (zp == PTR(z) + ABSIZ(z)); + + /* low byte of word after most significant */ + ASSERT (dp == (unsigned char *) data + + (order < 0 ? count*size : - (mp_size_t) size) + + (endian >= 0 ? (mp_size_t) size - 1 : 0)); + } + return data; +} |