#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;
}