Reverse

#include <stdio.h>
#include <string.h>

//string reverse

int main(){
        char *x = "ala ma kota";
        char *y;

        // assembler
        asm volatile(
        ".intel_syntax noprefix;"
        "mov si,OFFSET *x;"
        "cld;"
        "repne scasb;"
        "dec di"

        "reverse:"
        "mov al, [si];"
        "mov bl, [di];"
        "mov [si], bl;"
        "mov [di], al;"
        "inc si;"
        "dec di;"
        "cmp di, si;"
        "jae reverse;"

        "mov %0, %1;"

        ".att_syntax prefix;"
        :"=r"(*y)
        :"r"(*x)
        :"eax","edx","ebx","ecx","di","si"
        );

       printf("y=%d\n",*y);

}