func loadl16(r int, d int64) uint32 {
	v := uint16(d)
	if v == 0 {
		// Avoid generating "ori r,r,0", r != 0. Instead, generate the architectually preferred nop.
		// For example, "ori r31,r31,0" is a special execution serializing nop on Power10 called "exser".
		return NOP
	}
	return LOP_IRR(OP_ORI, uint32(r), uint32(r), uint32(v))
}

// Load the upper 16 bits of a 32b constant into register r.