asm("xchgb %%ah,%%al;xchgb %%dh,%%dl;"\
"roll $16,%%eax; roll $16,%%edx; "\
"xchgb %%ah,%%al;xchgb %%dh,%%dl;" \
: "=a"(lo),"=d"(hi) \
asm("xchgb %%ah,%%al;xchgb %%dh,%%dl;"\
"roll $16,%%eax; roll $16,%%edx; "\
"xchgb %%ah,%%al;xchgb %%dh,%%dl;" \
: "=a"(lo),"=d"(hi) \