#include <string.h>
char* strcat(char* s, const char* append)
{
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"(append), "1"(s), "2"(0), "3"(0xffffffff)
: "memory");
return s;
}