1 /* Optimized strcmp implementation for PowerPC.
2 Copyright (C) 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
22 /* See strlen.s for comments on how the end-of-string testing works. */
25 /* int [r3] strcmp (const char *p1 [r3], const char *p2 [r4]) */
27 /* General register assignments:
29 r3: pointer to previous word in s1
30 r4: pointer to previous word in s2
31 r5: current word from s1
32 r6: current word from s2
35 r9: ~(word in s1 | 0x7f7f7f7f) */
37 /* Register assignments in the prologue:
38 r10: low 2 bits of p2-p1
39 r11: mask to orc with r5/r6 */
62 /* OK. We've hit the end of the string. We need to be careful that
63 we don't compare two strings as different because of gunk beyond
64 the end of the strings... */
91 /* Oh well. In this case, we just do a byte-by-byte comparison. */