diff options
Diffstat (limited to 'libc/string/i386/memcpy.c')
-rw-r--r-- | libc/string/i386/memcpy.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/libc/string/i386/memcpy.c b/libc/string/i386/memcpy.c new file mode 100644 index 000000000..b2e0236f5 --- /dev/null +++ b/libc/string/i386/memcpy.c @@ -0,0 +1,54 @@ +/* + * 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 + */ + +#define _GNU_SOURCE +#include <string.h> + +void attribute_hidden *__memcpy(void * to, const void * from, size_t n) +{ + int d0, d1, d2; + __asm__ __volatile__( + "rep ; movsl\n\t" + "testb $2,%b4\n\t" + "je 1f\n\t" + "movsw\n" + "1:\ttestb $1,%b4\n\t" + "je 2f\n\t" + "movsb\n" + "2:" + : "=&c" (d0), "=&D" (d1), "=&S" (d2) + :"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from) + : "memory"); + return (to); +} + +strong_alias(__memcpy, memcpy) |