1 /* mpz_inp_raw -- read an mpz_t in raw format.
3 Copyright 2001, 2002, 2005 Free Software Foundation, Inc.
5 This file is part of the GNU MP Library.
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of the GNU Lesser General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or (at your
10 option) any later version.
12 The GNU MP Library is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
15 License for more details.
17 You should have received a copy of the GNU Lesser General Public License
18 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
25 /* NTOH_LIMB_FETCH fetches a limb which is in network byte order (ie. big
26 endian) and produces a normal host byte order result. */
28 #if HAVE_LIMB_BIG_ENDIAN
29 #define NTOH_LIMB_FETCH(limb, src) do { (limb) = *(src); } while (0)
32 #if HAVE_LIMB_LITTLE_ENDIAN
33 #define NTOH_LIMB_FETCH(limb, src) BSWAP_LIMB_FETCH (limb, src)
36 #ifndef NTOH_LIMB_FETCH
37 #define NTOH_LIMB_FETCH(limb, src) \
39 const unsigned char *__p = (const unsigned char *) (src); \
43 for (__i = 0; __i < BYTES_PER_MP_LIMB; __i++) \
44 __limb = (__limb << 8) | __p[__i]; \
50 /* Enhancement: The byte swap loop ought to be safe to vectorize on Cray
51 etc, but someone who knows what they're doing needs to check it. */
54 mpz_inp_raw (mpz_ptr x
, FILE *fp
)
56 unsigned char csize_bytes
[4];
57 mp_size_t csize
, abs_xsize
, i
;
61 mp_limb_t slimb
, elimb
;
66 /* 4 bytes for size */
67 if (fread (csize_bytes
, sizeof (csize_bytes
), 1, fp
) != 1)
71 ( (mp_size_t
) csize_bytes
[0] << 24)
72 + ((mp_size_t
) csize_bytes
[1] << 16)
73 + ((mp_size_t
) csize_bytes
[2] << 8)
74 + ((mp_size_t
) csize_bytes
[3]);
76 /* Sign extend if necessary.
77 Could write "csize -= ((csize & 0x80000000L) << 1)", but that tickles a
78 bug in gcc 3.0 for powerpc64 on AIX. */
79 if (sizeof (csize
) > 4 && csize
& 0x80000000L
)
80 csize
-= 0x80000000L
<< 1;
82 abs_csize
= ABS (csize
);
84 /* round up to a multiple of limbs */
85 abs_xsize
= (abs_csize
*8 + GMP_NUMB_BITS
-1) / GMP_NUMB_BITS
;
89 MPZ_REALLOC (x
, abs_xsize
);
92 /* Get limb boundaries right in the read, for the benefit of the
95 cp
= (char *) (xp
+ abs_xsize
) - abs_csize
;
96 if (fread (cp
, abs_csize
, 1, fp
) != 1)
99 if (GMP_NAIL_BITS
== 0)
101 /* Reverse limbs to least significant first, and byte swap. If
102 abs_xsize is odd then on the last iteration elimb and slimb are
103 the same. It doesn't seem extra code to handle that case
104 separately, to save an NTOH. */
106 ep
= xp
+ abs_xsize
-1;
107 for (i
= 0; i
< (abs_xsize
+1)/2; i
++)
109 NTOH_LIMB_FETCH (elimb
, ep
);
110 NTOH_LIMB_FETCH (slimb
, sp
);
117 /* It ought to be possible to do the transformation in-place, but
118 for now it's easier to use an extra temporary area. */
119 mp_limb_t byte
, limb
;
126 tp
= TMP_ALLOC_LIMBS (abs_xsize
);
130 for (i
= abs_csize
-1; i
>= 0; i
--)
132 byte
= (unsigned char) cp
[i
];
133 limb
|= (byte
<< bits
);
135 if (bits
>= GMP_NUMB_BITS
)
137 ASSERT (tpos
< abs_xsize
);
138 tp
[tpos
++] = limb
& GMP_NUMB_MASK
;
139 bits
-= GMP_NUMB_BITS
;
141 limb
= byte
>> (8 - bits
);
146 ASSERT (tpos
< abs_xsize
);
149 ASSERT (tpos
== abs_xsize
);
151 MPN_COPY (xp
, tp
, abs_xsize
);
155 /* GMP 1.x mpz_out_raw wrote high zero bytes, strip any high zero
156 limbs resulting from this. Should be a non-zero value here, but
157 for safety don't assume that. */
158 MPN_NORMALIZE (xp
, abs_xsize
);
161 SIZ(x
) = (csize
>= 0 ? abs_xsize
: -abs_xsize
);
162 return abs_csize
+ 4;