MULLD $20, R4                   // 1c840014
	MULLD $200000000, R4            // 641f0beb63ffc2007c9f21d2

	MULLDCC R3, R4, R5              // 7ca419d3
	MULHD R3, R4, R5                // 7ca41892
	MULHDCC R3, R4, R5              // 7ca41893
	MULHDU R3, R4, R5               // 7ca41812
	MULHDUCC R3, R4, R5             // 7ca41813

	MULLWV R3, R4                   // 7c841dd6

		{name: "MULLWload", argLength: 3, reg: gpopload, asm: "MULLW", aux: "SymOff", resultInArg0: true, clobberFlags: true, faultOnNilArg1: true, symEffect: "Read"}, // arg0 * *arg1. arg2=mem

		{name: "MULHD", argLength: 2, reg: gp21tmp, asm: "MULHD", typ: "Int64", commutative: true, resultInArg0: true, clobberFlags: true},   // (arg0 * arg1) >> width

(Avg64u <t> x y) => (ADD (SRDconst <t> (SUB <t> x y) [1]) y)

(Mul64 ...) => (MULLD ...)
(Mul(32|16|8) ...) => (MULLW ...)
(Select0 (Mul64uhilo x y)) => (MULHDU x y)
(Select1 (Mul64uhilo x y)) => (MULLD x y)

(Div64 [false] x y) => (DIVD x y)
(Div64u ...) => (DIVDU ...)
(Div32 [false] x y) => (DIVW x y)
(Div32u ...) => (DIVWU ...)
(Div16 [false]  x y) => (DIVW  (SignExt16to32 x) (SignExt16to32 y))

// TODO(mundaym): indexed versions of these?
((ADD|SUB|MULLD|AND|OR|XOR) <t> x g:(MOVDload [off] {sym} ptr mem))
  && ptr.Op != OpSB
  && is20Bit(int64(off))
  && canMergeLoadClobber(v, g, x)
  && clobber(g)
  => ((ADD|SUB|MULLD|AND|OR|XOR)load <t> [off] {sym} x ptr mem)
((ADD|SUB|MULL|AND|OR|XOR)W <t> x g:(MOVWload [off] {sym} ptr mem))
  && ptr.Op != OpSB
  && is20Bit(int64(off))