/* * 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 strncat //#define strncat TESTING char *strncat(char * dest, const char * src, size_t count) { int esi, edi, eax, ecx, edx; __asm__ __volatile__( " xorl %%eax, %%eax\n" " incl %%edx\n" " pushl %%edi\n" /* save dest */ " repne; scasb\n" " decl %%edi\n" /* edi => NUL in dest */ /* count-- */ "1: decl %%edx\n" /* if count reached 0, store NUL and bail out */ " movl %%edx, %%eax\n" " jz 2f\n" /* else copy a char */ " lodsb\n" "2: stosb\n" " testb %%al, %%al\n" " jnz 1b\n" /* end of loop */ " popl %%eax\n" /* restore dest into eax */ : "=&S" (esi), "=&D" (edi), "=&a" (eax), "=&c" (ecx), "=&d" (edx) : "0" (src), "1" (dest), "3" (0xffffffff), "4" (count) : "memory" ); return (char *)eax; } #ifndef strncat libc_hidden_def(strncat) #else /* Uncomment TESTING, gcc -m32 -Os strncat.c -o strncat * and run ./strncat */ int main() { char buf[99]; strcpy(buf, "abc"); buf[4] = '*'; strncat(buf, "def", 0); printf(strcmp(buf, "abc") == 0 && buf[4] == '*' ? "ok\n" : "BAD!\n"); strcpy(buf, "abc"); buf[6] = 1; buf[7] = '*'; strncat(buf, "def", 50); printf(strcmp(buf, "abcdef") == 0 && buf[7] == '*' ? "ok\n" : "BAD!\n"); strcpy(buf, "abc"); buf[6] = 1; buf[7] = '*'; strncat(buf, "def", -1); printf(strcmp(buf, "abcdef") == 0 && buf[7] == '*' ? "ok\n" : "BAD!\n"); strcpy(buf, "abc"); buf[6] = 1; buf[7] = '*'; strncat(buf, "def123", 3); printf(strcmp(buf, "abcdef") == 0 && buf[7] == '*' ? "ok\n" : "BAD!\n"); } #endif