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/*
* This string-include defines all string functions as inline
* functions. Use gcc. It also assumes ds=es=data space, this should be
* normal. Most of the string-functions are rather heavily hand-optimized,
* see especially strtok,strstr,str[c]spn. They should work, but are not
* very easy to understand. Everything is done entirely within the register
* set, making the functions fast and clean. String instructions have been
* used through-out, making for "slightly" unclear code :-)
*
* NO Copyright (C) 1991, 1992 Linus Torvalds,
* consider these trivial functions to be PD.
*/
/*
* Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
*
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
/*
* Modified for uClibc by Erik Andersen <andersen@codepoet.org>
* These make no attempt to use nifty things like mmx/3dnow/etc.
* These are not inline, and will therefore not be as fast as
* modifying the headers to use inlines (and cannot therefore
* do tricky things when dealing with const memory). But they
* should (I hope!) be faster than their generic equivalents....
*
* More importantly, these should provide a good example for
* others to follow when adding arch specific optimizations.
* -Erik
*/
#include <string.h>
#undef strncmp
int strncmp(const char *cs, const char *ct, size_t count)
{
int eax;
int esi, edi, ecx;
__asm__ __volatile__(
" incl %%ecx\n"
"1: decl %%ecx\n"
" jz 2f\n"
" lodsb\n"
" scasb\n"
" jne 3f\n"
" testb %%al, %%al\n"
" jnz 1b\n"
"2: xorl %%eax, %%eax\n"
" jmp 4f\n"
"3: sbbl %%eax, %%eax\n"
" orb $1, %%al\n"
"4:\n"
: "=a" (eax), "=&S" (esi), "=&D" (edi), "=&c" (ecx)
: "1" (cs), "2" (ct), "3" (count)
);
return eax;
}
libc_hidden_weak(strncmp)
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