Embedding 0x03 in C

0x03.c

#include <stdio.h>

static int x3(int a, int b) {

    int out;
    asm(
        // it's not stated in xchg rax,rax but it's
        // intel syntax. Note the noprefix means we
        // don't need % before registers
        ".intel_syntax noprefix;"
        // a bit of preamble to get registers
        // set up correctly. We're okay with just working
        // with int rather than long int
        "mov eax, %1;"
        "mov edx, %2;"

        // 0x03 code below
        "sub rdx, rax;"
        "sbb rcx,rcx;"
        "and rcx,rdx;"
        "add rax,rcx;"

        // put the result into out
        "mov %0, eax;"
        // tell the compiler that out is in memory
        : "=m" (out)
        // tell the compiler that a and b are inputs
        : "m" (a) , "m" (b)
        // this is the list of registers which are clobbered
        : "rax","rdx","rcx");
    return out;
}

struct input {
    int a;
    int b;
};

int main(int argc, const char **argv) {


    struct input inputs[] = {
        {0x0, 0x1},
        {0x1, 0x1},
        {0xf, 0xe},
        {0xe, 0xf},
        {~0, 0x00},
    };

    for (int i = 0; i < sizeof(inputs)/sizeof(inputs[0]); i++) {
        printf("%d (rax: %016x rdx %016x) ->  rax: %016x\n",
                i, inputs[i].a, inputs[i].b, x3(inputs[i].a, inputs[i].b));
    }
   return 0;
}