1 /* bignum_copy.c - copy a bignum 2 Copyright 1987, 1990, 1991, 1992, 1993, 2000 3 Free Software Foundation, Inc. 4 5 This file is part of GAS, the GNU Assembler. 6 7 GAS is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2, or (at your option) 10 any later version. 11 12 GAS is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GAS; see the file COPYING. If not, write to 19 the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 20 21 #include "as.h" 22 23 /* 24 * bignum_copy () 25 * 26 * Copy a bignum from in to out. 27 * If the output is shorter than the input, copy lower-order littlenums. 28 * Return 0 or the number of significant littlenums dropped. 29 * Assumes littlenum arrays are densely packed: no unused chars between 30 * the littlenums. Uses memcpy() to move littlenums, and wants to 31 * know length (in chars) of the input bignum. 32 */ 33 34 /* void */ 35 int 36 bignum_copy (register LITTLENUM_TYPE *in, 37 register int in_length, /* in sizeof(littlenum)s */ 38 register LITTLENUM_TYPE *out, 39 register int out_length /* in sizeof(littlenum)s */) 40 { 41 int significant_littlenums_dropped; 42 43 if (out_length < in_length) 44 { 45 LITTLENUM_TYPE *p; /* -> most significant (non-zero) input 46 littlenum. */ 47 48 memcpy ((void *) out, (void *) in, 49 (unsigned int) out_length << LITTLENUM_SHIFT); 50 for (p = in + in_length - 1; p >= in; --p) 51 { 52 if (*p) 53 break; 54 } 55 significant_littlenums_dropped = p - in - in_length + 1; 56 57 if (significant_littlenums_dropped < 0) 58 { 59 significant_littlenums_dropped = 0; 60 } 61 } 62 else 63 { 64 memcpy ((char *) out, (char *) in, 65 (unsigned int) in_length << LITTLENUM_SHIFT); 66 67 if (out_length > in_length) 68 { 69 memset ((char *) (out + in_length), 70 '\0', 71 (unsigned int) (out_length - in_length) << LITTLENUM_SHIFT); 72 } 73 74 significant_littlenums_dropped = 0; 75 } 76 77 return (significant_littlenums_dropped); 78 } /* bignum_copy() */ 79 80 /* end of bignum-copy.c */ 81