--- /dev/null
+/* mpz_export -- create word data from mpz.
+
+Copyright 2002, 2003 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 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.
+
+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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
+
+#include <stdio.h> /* for NULL */
+#include "gmp.h"
+#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
+
+
+#define MPN_SIZEINBASE_2EXP(result, ptr, size, base2exp) \
+ do { \
+ int __cnt; \
+ unsigned long __totbits; \
+ ASSERT ((size) > 0); \
+ ASSERT ((ptr)[(size)-1] != 0); \
+ count_leading_zeros (__cnt, (ptr)[(size)-1]); \
+ __totbits = (size) * GMP_NUMB_BITS - (__cnt - GMP_NAIL_BITS); \
+ (result) = (__totbits + (base2exp)-1) / (base2exp); \
+ } while (0)
+
+
+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 (8*size-nail > 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;
+}
projects / msp430-gcc.git / blobdiff