| 1 | /* bignum_copy.c - copy a bignum |
| 2 | Copyright (C) 1987, 1990, 1991, 1992 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GAS, the GNU Assembler. |
| 5 | |
| 6 | GAS is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | GAS is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GAS; see the file COPYING. If not, write to |
| 18 | the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 19 | |
| 20 | #include "as.h" |
| 21 | |
| 22 | /* |
| 23 | * bignum_copy () |
| 24 | * |
| 25 | * Copy a bignum from in to out. |
| 26 | * If the output is shorter than the input, copy lower-order littlenums. |
| 27 | * Return 0 or the number of significant littlenums dropped. |
| 28 | * Assumes littlenum arrays are densely packed: no unused chars between |
| 29 | * the littlenums. Uses memcpy() to move littlenums, and wants to |
| 30 | * know length (in chars) of the input bignum. |
| 31 | */ |
| 32 | |
| 33 | /* void */ |
| 34 | int |
| 35 | bignum_copy (in, in_length, out, out_length) |
| 36 | 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 */ |