/* * 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 memcpy void *memcpy(void * to, const void * from, size_t n) { int d0, d1, d2; __asm__ __volatile__( " rep; movsl\n" " movl %4, %%ecx\n" " andl $3, %%ecx\n" /* jz is optional. avoids "rep; movsb" with ecx == 0, * but adds a branch, which is currently (2008) faster */ " jz 1f\n" " rep; movsb\n" "1:\n" : "=&c" (d0), "=&D" (d1), "=&S" (d2) : "0" (n / 4), "g" (n), "1" ((long)to), "2" ((long)from) : "memory" ); return to; } libc_hidden_def(memcpy)