prog.Reg = p.getRegister(prog, op, &a[1])
				prog.To = a[2]
			}
		case sys.I386:
			prog.From = a[0]
			prog.AddRestSource(a[1])
			prog.To = a[2]
		case sys.PPC64:
			if arch.IsPPC64CMP(op) {
				// CMPW etc.; third argument is a CR register that goes into prog.Reg.
				prog.From = a[0]
				prog.Reg = p.getRegister(prog, op, &a[2])
				prog.To = a[1]
				break
			}

			prog.From = a[0]