opxy = op_NY
		case AOR:
			opxy = op_OG
		case AORW:
			opx = op_O
			opxy = op_OY
		case AXOR:
			opxy = op_XG
		case AXORW:
			opx = op_X
			opxy = op_XY
		}
		if opx != 0 && 0 <= d2 && d2 < DISP12 {
			zRX(opx, uint32(r1), uint32(x2), uint32(b2), uint32(d2), asm)
		} else {
			zRXY(opxy, uint32(r1), uint32(x2), uint32(b2), uint32(d2), asm)
		}

}

func OPBLR(x uint32) uint32 {
	/* x=0, JMP; 1, CALL; 2, RET */
	return 0x6B<<25 | 0<<23 | x<<21 | 0x1F<<16 | 0<<10
}

func SYSOP(l uint32, op0 uint32, op1 uint32, crn uint32, crm uint32, op2 uint32, rt uint32) uint32 {
	return 0x354<<22 | l<<21 | op0<<19 | op1<<16 | crn&15<<12 | crm&15<<8 | op2<<5 | rt
}

func SYSHINT(x uint32) uint32 {
	return SYSOP(0, 0, 3, 2, 0, x, 0x1F)
}