// BEQZ/BNEZ can be encoded with 21-bit offsets.
				width = 21
				as = -as
				if rj == 0 || rj == REGZERO {
					rj = rd
				}
			}
		}
		switch width {
		case 21:
			if (v<<11)>>11 != v {
				c.ctxt.Diag("21 bit-width, short branch too far\n%v", p)
			}
			o1 = OP_16IR_5I(c.opirr(as), uint32(v), uint32(rj))
		case 16:
			if (v<<16)>>16 != v {

	// overflow, the 20 top bits would be 1, and the sign bit for
	// the low 12 bits would be set, in which case the entire 32
	// bit pattern fits in a 12 bit signed value.
	if imm&(1<<11) != 0 {
		high++
	}

	low = signExtend(imm, 12)
	high = signExtend(high, 20)

	return low, high, nil
}

func regVal(r, min, max uint32) uint32 {
	if r < min || r > max {