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" ...