1 /*
2 * This string-include defines all string functions as inline
3 * functions. Use gcc. It also assumes ds=es=data space, this should be
4 * normal. Most of the string-functions are rather heavily hand-optimized,
5 * see especially strtok,strstr,str[c]spn. They should work, but are not
6 * very easy to understand. Everything is done entirely within the register
7 * set, making the functions fast and clean. String instructions have been
8 * used through-out, making for "slightly" unclear code :-)
9 *
10 * NO Copyright (C) 1991, 1992 Linus Torvalds,
11 * consider these trivial functions to be PD.
12 */
13
14 /*
15 * Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
16 *
17 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
18 */
19
20 /*
21 * Modified for uClibc by Erik Andersen <andersen@codepoet.org>
22 * These make no attempt to use nifty things like mmx/3dnow/etc.
23 * These are not inline, and will therefore not be as fast as
24 * modifying the headers to use inlines (and cannot therefore
25 * do tricky things when dealing with const memory). But they
26 * should (I hope!) be faster than their generic equivalents....
27 *
28 * More importantly, these should provide a good example for
29 * others to follow when adding arch specific optimizations.
30 * -Erik
31 */
32
33 #include <string.h>
34
35 #undef strncmp
strncmp(const char * cs,const char * ct,size_t count)36 int strncmp(const char *cs, const char *ct, size_t count)
37 {
38 int eax;
39 int esi, edi, ecx;
40 __asm__ __volatile__(
41 " incl %%ecx\n"
42 "1: decl %%ecx\n"
43 " jz 2f\n"
44 " lodsb\n"
45 " scasb\n"
46 " jne 3f\n"
47 " testb %%al, %%al\n"
48 " jnz 1b\n"
49 "2: xorl %%eax, %%eax\n"
50 " jmp 4f\n"
51 "3: sbbl %%eax, %%eax\n"
52 " orb $1, %%al\n"
53 "4:\n"
54 : "=a" (eax), "=&S" (esi), "=&D" (edi), "=&c" (ecx)
55 : "1" (cs), "2" (ct), "3" (count)
56 );
57 return eax;
58 }
59 libc_hidden_weak(strncmp)
60