(Less32 x y) => (LessThan (CMP x y))
(Less(32|64)F x y) => (GreaterThan (CMP(F|D) y x)) // reverse operands to work around NaN

(Less8U x y)  => (LessThanU (CMP (ZeroExt8to32 x) (ZeroExt8to32 y)))
(Less16U x y) => (LessThanU (CMP (ZeroExt16to32 x) (ZeroExt16to32 y)))
(Less32U x y) => (LessThanU (CMP x y))

(Leq8 x y)  => (LessEqual (CMP (SignExt8to32 x) (SignExt8to32 y)))
(Leq16 x y) => (LessEqual (CMP (SignExt16to32 x) (SignExt16to32 y)))

		{name: "FRINTPD", argLength: 1, reg: fp11, asm: "FRINTPD"},
		{name: "FRINTZD", argLength: 1, reg: fp11, asm: "FRINTZD"},

		// conditional instructions; auxint is
		// one of the arm64 comparison pseudo-ops (LessThan, LessThanU, etc.)
		{name: "CSEL", argLength: 3, reg: gp2flags1, asm: "CSEL", aux: "CCop"},   // auxint(flags) ? arg0 : arg1
		{name: "CSEL0", argLength: 2, reg: gp1flags1, asm: "CSEL", aux: "CCop"},  // auxint(flags) ? arg0 : 0