C语言模拟X86通用寄存器

#include<stdio.h>
typedef unsigned char BYTE;
typedef unsigned short WORD;

int main()
{
    union
    {
        struct
        {
            WORD ax,bx,cx,dx;
        }word;
        struct
        {
            BYTE al,ah,bl,bh,cl,ch,dl,dh;
        }byte;
    }regs;

    regs.byte.ah=0x12;
    regs.byte.al=0x34;

    printf("0x%hx\n",regs.word.ax);

    return 0;
}