/* * 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. * * 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 _STDIO_UTILITY #define _GNU_SOURCE #include <string.h> #include <locale.h> /* for __LOCALE_C_ONLY */ #ifdef L_strcpy char * strcpy(char * dest, const char * src) { int d0, d1, d2; __asm__ __volatile__( "1:\tlodsb\n\t" "stosb\n\t" "testb %%al,%%al\n\t" "jne 1b" : "=&S" (d0), "=&D" (d1), "=&a" (d2) :"0" (src),"1" (dest) : "memory"); return dest; } #endif #ifdef L_strncpy char * strncpy(char * dest, const char * src, size_t count) { int d0, d1, d2, d3; __asm__ __volatile__( "1:\tdecl %2\n\t" "js 2f\n\t" "lodsb\n\t" "stosb\n\t" "testb %%al,%%al\n\t" "jne 1b\n\t" "rep\n\t" "stosb\n" "2:" : "=&S" (d0), "=&D" (d1), "=&c" (d2), "=&a" (d3) :"0" (src),"1" (dest),"2" (count) : "memory"); return dest; } #endif #ifdef L_strcat char *strcat(char * dest, const char * src) { int d0, d1, d2, d3; __asm__ __volatile__( "repne\n\t" "scasb\n\t" "decl %1\n" "1:\tlodsb\n\t" "stosb\n\t" "testb %%al,%%al\n\t" "jne 1b" : "=&S" (d0), "=&D" (d1), "=&a" (d2), "=&c" (d3) : "0" (src), "1" (dest), "2" (0), "3" (0xffffffff):"memory"); return dest; } #endif #ifdef L_strncat char *strncat(char * dest, const char * src, size_t count) { int d0, d1, d2, d3; __asm__ __volatile__( "repne\n\t" "scasb\n\t" "decl %1\n\t" "movl %8,%3\n" "1:\tdecl %3\n\t" "js 2f\n\t" "lodsb\n\t" "stosb\n\t" "testb %%al,%%al\n\t" "jne 1b\n" "2:\txorl %2,%2\n\t" "stosb" : "=&S" (d0), "=&D" (d1), "=&a" (d2), "=&c" (d3) : "0" (src),"1" (dest),"2" (0),"3" (0xffffffff), "g" (count) : "memory"); return dest; } #endif #ifdef L_strcmp int strcmp(const char *cs, const char *ct) { int d0, d1; register int __res; __asm__ __volatile__( "1:\tlodsb\n\t" "scasb\n\t" "jne 2f\n\t" "testb %%al,%%al\n\t" "jne 1b\n\t" "xorl %%eax,%%eax\n\t" "jmp 3f\n" "2:\tsbbl %%eax,%%eax\n\t" "orb $1,%%al\n" "3:" :"=a" (__res), "=&S" (d0), "=&D" (d1) :"1" (cs),"2" (ct)); return __res; } #ifdef __LOCALE_C_ONLY weak_alias(strcmp,strcoll); #endif /* __LOCALE_C_ONLY */ #endif #ifdef L_strncmp int strncmp(const char *cs, const char *ct, size_t count) { register int __res; int d0, d1, d2; __asm__ __volatile__( "1:\tdecl %3\n\t" "js 2f\n\t" "lodsb\n\t" "scasb\n\t" "jne 3f\n\t" "testb %%al,%%al\n\t" "jne 1b\n" "2:\txorl %%eax,%%eax\n\t" "jmp 4f\n" "3:\tsbbl %%eax,%%eax\n\t" "orb $1,%%al\n" "4:" :"=a" (__res), "=&S" (d0), "=&D" (d1), "=&c" (d2) :"1" (cs),"2" (ct),"3" (count)); return __res; } #endif #ifdef L_strchr char * strchr(const char *s, int c) { int d0; register char * __res; __asm__ __volatile__( "movb %%al,%%ah\n" "1:\tlodsb\n\t" "cmpb %%ah,%%al\n\t" "je 2f\n\t" "testb %%al,%%al\n\t" "jne 1b\n\t" "movl $1,%1\n" "2:\tmovl %1,%0\n\t" "decl %0" :"=a" (__res), "=&S" (d0) : "1" (s),"0" (c)); return __res; } weak_alias(strchr,index); #endif #ifdef L_strrchr char *strrchr(const char *s, int c) { int d0, d1; register char * __res; __asm__ __volatile__( "movb %%al,%%ah\n" "1:\tlodsb\n\t" "cmpb %%ah,%%al\n\t" "jne 2f\n\t" "leal -1(%%esi),%0\n" "2:\ttestb %%al,%%al\n\t" "jne 1b" :"=g" (__res), "=&S" (d0), "=&a" (d1) :"0" (0),"1" (s),"2" (c)); return __res; } weak_alias(strrchr,rindex); #endif #ifdef L_strlen size_t strlen(const char *s) { int d0; register int __res; __asm__ __volatile__( "repne\n\t" "scasb\n\t" "notl %0\n\t" "decl %0" :"=c" (__res), "=&D" (d0) :"1" (s),"a" (0), "0" (0xffffffff)); return __res; } #endif #ifdef L_strnlen size_t strnlen(const char *s, size_t count) { int d0; register int __res; __asm__ __volatile__( "movl %2,%0\n\t" "jmp 2f\n" "1:\tcmpb $0,(%0)\n\t" "je 3f\n\t" "incl %0\n" "2:\tdecl %1\n\t" "cmpl $-1,%1\n\t" "jne 1b\n" "3:\tsubl %2,%0" :"=a" (__res), "=&d" (d0) :"c" (s),"1" (count)); return __res; } #endif #ifdef L_memcpy void *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); } #endif #ifdef L_memmove void *memmove(void *dest, const void *src, size_t n) { int d0, d1, d2; if (dest<src) __asm__ __volatile__( "rep\n\t" "movsb" : "=&c" (d0), "=&S" (d1), "=&D" (d2) :"0" (n),"1" (src),"2" (dest) : "memory"); else __asm__ __volatile__( "std\n\t" "rep\n\t" "movsb\n\t" "cld" : "=&c" (d0), "=&S" (d1), "=&D" (d2) :"0" (n), "1" (n-1+(const char *)src), "2" (n-1+(char *)dest) :"memory"); return dest; } #endif #ifdef L_memchr void *memchr(const void *cs, int c, size_t count) { int d0; register void * __res; if (!count) return NULL; __asm__ __volatile__( "repne\n\t" "scasb\n\t" "je 1f\n\t" "movl $1,%0\n" "1:\tdecl %0" :"=D" (__res), "=&c" (d0) : "a" (c),"0" (cs),"1" (count)); return __res; } #endif #ifdef L_memset void *memset(void *s, int c, size_t count) { int d0, d1; __asm__ __volatile__( "rep\n\t" "stosb" : "=&c" (d0), "=&D" (d1) :"a" (c),"1" (s),"0" (count) :"memory"); return s; } #endif