/* mpz_inp_raw -- read an mpz_t in raw format. Copyright 2001, 2002 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 2.1 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; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include "gmp.h" #include "gmp-impl.h" /* NTOH_LIMB_FETCH fetches a limb which is in network byte order (ie. big endian) and produces a normal host byte order result. */ #if HAVE_LIMB_BIG_ENDIAN #define NTOH_LIMB_FETCH(limb, src) do { (limb) = *(src); } while (0) #endif /* The generic implementations below very likely come out as lots of separate byte fetches, so if we know the host is little endian then instead use a single load and a purely arithmetic BSWAP_LIMB. */ #if HAVE_LIMB_LITTLE_ENDIAN #define NTOH_LIMB_FETCH(limb, src) BSWAP_LIMB_FETCH (limb, src) #endif #if ! defined (NTOH_LIMB_FETCH) #if BITS_PER_MP_LIMB == 8 #define NTOH_LIMB_FETCH(limb, src) do { (limb) = *(src); } while (0) #endif #if BITS_PER_MP_LIMB == 16 #define NTOH_LIMB_FETCH(limb, src) \ do { \ const unsigned char *__p = (const unsigned char *) (src); \ (limb) = \ ( (mp_limb_t) __p[0] << 8) \ + (mp_limb_t) __p[1]; \ } while (0) #endif #if BITS_PER_MP_LIMB == 32 #define NTOH_LIMB_FETCH(limb, src) \ do { \ const unsigned char *__p = (const unsigned char *) (src); \ (limb) = \ ( (mp_limb_t) __p[0] << 24) \ + ((mp_limb_t) __p[1] << 16) \ + ((mp_limb_t) __p[2] << 8) \ + (mp_limb_t) __p[3]; \ } while (0) #endif #if ! defined (NTOH_LIMB_FETCH) && BITS_PER_MP_LIMB == 64 #define NTOH_LIMB_FETCH(limb, src) \ do { \ const unsigned char *__p = (const unsigned char *) (src); \ (limb) = \ ( (mp_limb_t) __p[0] << 56) \ + ((mp_limb_t) __p[1] << 48) \ + ((mp_limb_t) __p[2] << 40) \ + ((mp_limb_t) __p[3] << 32) \ + ((mp_limb_t) __p[4] << 24) \ + ((mp_limb_t) __p[5] << 16) \ + ((mp_limb_t) __p[6] << 8) \ + (mp_limb_t) __p[7]; \ } while (0) #endif #endif /* Enhancement: The byte swap loop ought to be safe to vectorize on Cray etc, but someone who knows what they're doing needs to check it. */ size_t mpz_inp_raw (mpz_ptr x, FILE *fp) { unsigned char csize_bytes[4]; mp_size_t csize, abs_xsize, i; size_t abs_csize; char *cp; mp_ptr xp, sp, ep; mp_limb_t slimb, elimb; if (fp == 0) fp = stdin; /* 4 bytes for size */ if (fread (csize_bytes, sizeof (csize_bytes), 1, fp) != 1) return 0; csize = ( (mp_size_t) csize_bytes[0] << 24) + ((mp_size_t) csize_bytes[1] << 16) + ((mp_size_t) csize_bytes[2] << 8) + ((mp_size_t) csize_bytes[3]); /* Sign extend if necessary. Could write "csize -= ((csize & 0x80000000L) << 1)", but that tickles a bug in gcc 3.0 for powerpc64 on AIX. */ if (sizeof (csize) > 4 && csize & 0x80000000L) csize -= 0x80000000L << 1; abs_csize = ABS (csize); /* round up to a multiple of limbs */ abs_xsize = (abs_csize*8 + GMP_NUMB_BITS-1) / GMP_NUMB_BITS; if (abs_xsize != 0) { MPZ_REALLOC (x, abs_xsize); xp = PTR(x); /* Get limb boundaries right in the read, for the benefit of the non-nails case. */ xp[0] = 0; cp = (char *) (xp + abs_xsize) - abs_csize; if (fread (cp, abs_csize, 1, fp) != 1) return 0; if (GMP_NAIL_BITS == 0) { /* Reverse limbs to least significant first, and byte swap. If abs_xsize is odd then on the last iteration elimb and slimb are the same. It doesn't seem extra code to handle that case separately, to save an NTOH. */ sp = xp; ep = xp + abs_xsize-1; for (i = 0; i < (abs_xsize+1)/2; i++) { NTOH_LIMB_FETCH (elimb, ep); NTOH_LIMB_FETCH (slimb, sp); *sp++ = elimb; *ep-- = slimb; } } else { /* It ought to be possible to do the transformation in-place, but for now it's easier to use an extra temporary area. */ mp_limb_t byte, limb; int bits; mp_size_t tpos; mp_ptr tp; TMP_DECL (marker); TMP_MARK (marker); tp = TMP_ALLOC_LIMBS (abs_xsize); limb = 0; bits = 0; tpos = 0; for (i = abs_csize-1; i >= 0; i--) { byte = (unsigned char) cp[i]; limb |= (byte << bits); bits += 8; if (bits >= GMP_NUMB_BITS) { ASSERT (tpos < abs_xsize); tp[tpos++] = limb & GMP_NUMB_MASK; bits -= GMP_NUMB_BITS; ASSERT (bits < 8); limb = byte >> (8 - bits); } } if (bits != 0) { ASSERT (tpos < abs_xsize); tp[tpos++] = limb; } ASSERT (tpos == abs_xsize); MPN_COPY (xp, tp, abs_xsize); TMP_FREE (marker); } /* GMP 1.x mpz_out_raw wrote high zero bytes, strip any high zero limbs resulting from this. Should be a non-zero value here, but for safety don't assume that. */ MPN_NORMALIZE (xp, abs_xsize); } SIZ(x) = (csize >= 0 ? abs_xsize : -abs_xsize); return abs_csize + 4; }