1 /* mpz_out_raw -- write an mpz_t in raw format.
2
3 Copyright 2001, 2002 Free Software Foundation, Inc.
4
5 This file is part of the GNU MP Library.
6
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of either:
9
10 * the GNU Lesser General Public License as published by the Free
11 Software Foundation; either version 3 of the License, or (at your
12 option) any later version.
13
14 or
15
16 * the GNU General Public License as published by the Free Software
17 Foundation; either version 2 of the License, or (at your option) any
18 later version.
19
20 or both in parallel, as here.
21
22 The GNU MP Library is distributed in the hope that it will be useful, but
23 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
25 for more details.
26
27 You should have received copies of the GNU General Public License and the
28 GNU Lesser General Public License along with the GNU MP Library. If not,
29 see https://www.gnu.org/licenses/. */
30
31 #include <stdio.h>
32 #include "gmp-impl.h"
33 #include "longlong.h"
34
35
36 /* HTON_LIMB_STORE takes a normal host byte order limb and stores it as
37 network byte order (ie. big endian). */
38
39 #if HAVE_LIMB_BIG_ENDIAN
40 #define HTON_LIMB_STORE(dst, limb) do { *(dst) = (limb); } while (0)
41 #endif
42
43 #if HAVE_LIMB_LITTLE_ENDIAN
44 #define HTON_LIMB_STORE(dst, limb) BSWAP_LIMB_STORE (dst, limb)
45 #endif
46
47 #ifndef HTON_LIMB_STORE
48 #define HTON_LIMB_STORE(dst, limb) \
49 do { \
50 mp_limb_t __limb = (limb); \
51 char *__p = (char *) (dst); \
52 int __i; \
53 for (__i = 0; __i < GMP_LIMB_BYTES; __i++) \
54 __p[__i] = (char) (__limb >> ((GMP_LIMB_BYTES-1 - __i) * 8)); \
55 } while (0)
56 #endif
57
58
59 size_t
60 mpz_out_raw (FILE *fp, mpz_srcptr x)
61 {
62 mp_size_t xsize, abs_xsize, bytes, i;
63 mp_srcptr xp;
64 char *tp, *bp;
65 mp_limb_t xlimb;
66 int zeros;
67 size_t tsize, ssize;
68
69 xsize = SIZ(x);
70 abs_xsize = ABS (xsize);
71 bytes = (abs_xsize * GMP_NUMB_BITS + 7) / 8;
72 tsize = ROUND_UP_MULTIPLE ((unsigned) 4, GMP_LIMB_BYTES) + bytes;
73
74 tp = __GMP_ALLOCATE_FUNC_TYPE (tsize, char);
75 bp = tp + ROUND_UP_MULTIPLE ((unsigned) 4, GMP_LIMB_BYTES);
76
77 if (bytes != 0)
78 {
79 bp += bytes;
80 xp = PTR (x);
81 i = abs_xsize;
82
83 if (GMP_NAIL_BITS == 0)
84 {
85 /* reverse limb order, and byte swap if necessary */
86 #ifdef _CRAY
87 _Pragma ("_CRI ivdep");
88 #endif
89 do
90 {
91 bp -= GMP_LIMB_BYTES;
92 xlimb = *xp;
93 HTON_LIMB_STORE ((mp_ptr) bp, xlimb);
94 xp++;
95 }
96 while (--i > 0);
97
98 /* strip high zero bytes (without fetching from bp) */
99 count_leading_zeros (zeros, xlimb);
100 zeros /= 8;
101 bp += zeros;
102 bytes -= zeros;
103 }
104 else
105 {
106 mp_limb_t new_xlimb;
107 int bits;
108 ASSERT_CODE (char *bp_orig = bp - bytes);
109
110 ASSERT_ALWAYS (GMP_NUMB_BITS >= 8);
111
112 bits = 0;
113 xlimb = 0;
114 for (;;)
115 {
116 while (bits >= 8)
117 {
118 ASSERT (bp > bp_orig);
119 *--bp = xlimb & 0xFF;
120 xlimb >>= 8;
121 bits -= 8;
122 }
123
124 if (i == 0)
125 break;
126
127 new_xlimb = *xp++;
128 i--;
129 ASSERT (bp > bp_orig);
130 *--bp = (xlimb | (new_xlimb << bits)) & 0xFF;
131 xlimb = new_xlimb >> (8 - bits);
132 bits += GMP_NUMB_BITS - 8;
133 }
134
135 if (bits != 0)
136 {
137 ASSERT (bp > bp_orig);
138 *--bp = xlimb;
139 }
140
141 ASSERT (bp == bp_orig);
142 while (*bp == 0)
143 {
144 bp++;
145 bytes--;
146 }
147 }
148 }
149
150 /* total bytes to be written */
151 ssize = 4 + bytes;
152
153 /* twos complement negative for the size value */
154 bytes = (xsize >= 0 ? bytes : -bytes);
155
156 /* so we don't rely on sign extension in ">>" */
157 ASSERT_ALWAYS (sizeof (bytes) >= 4);
158
159 bp[-4] = bytes >> 24;
160 bp[-3] = bytes >> 16;
161 bp[-2] = bytes >> 8;
162 bp[-1] = bytes;
163 bp -= 4;
164
165 if (fp == 0)
166 fp = stdout;
167 if (fwrite (bp, ssize, 1, fp) != 1)
168 ssize = 0;
169
170 (*__gmp_free_func) (tp, tsize);
171 return ssize;
172 }