(XOR x (MVN y)) => (EON x y)
(OR  x (MVN y)) => (ORN x y)
(MVN (XOR x y)) => (EON x y)
(NEG (NEG x)) => x

(CSEL [cc] (MOVDconst [-1]) (MOVDconst [0]) flag) => (CSETM [cc] flag)
(CSEL [cc] (MOVDconst [0]) (MOVDconst [-1]) flag) => (CSETM [arm64Negate(cc)] flag)
(CSEL [cc] x (MOVDconst [0]) flag) => (CSEL0 [cc] x flag)
(CSEL [cc] (MOVDconst [0]) y flag) => (CSEL0 [arm64Negate(cc)] y flag)

		} else {
			cond -= SPOP_EQ
		}

		r := int(p.Reg)
		var rf int = r
		if p.From3Type() == obj.TYPE_NONE {
			/* CINC/CINV/CNEG or CSET/CSETM*/
			if r == obj.REG_NONE {
				/* CSET/CSETM */
				rf = REGZERO
				r = rf
			}
			cond ^= 1
		} else {
			rf = int(p.GetFrom3().Reg) /* CSEL */
		}

		rt := int(p.To.Reg)