f->vconst &= 0xffff;
if(f->vconst & 0x8000){
f->vconst |= 0xffff0000;
f->vconst |= (vlong)~0 << 32;
f->vconst |= (uvlong)~0 << 32;
}
a = AMOVL;
f->vconst &= 0xff;
if(f->vconst & 0x80){
f->vconst |= 0xffffff00;
a = AMOVQ;