DIVD	R1, R2, R3            // b90400b2b90d00a1b904003b
	DIVW	R4, R5                // b90400b5b91d00a4b904005b
	DIVW	R4, R5, R6            // b90400b5b91d00a4b904006b
	DIVDU	R7, R8                // a7a90000b90400b8b98700a7b904008b
	DIVDU	R7, R8, R9            // a7a90000b90400b8b98700a7b904009b
	DIVWU	R1, R2                // a7a90000b90400b2b99700a1b904002b
	DIVWU	R1, R2, R3            // a7a90000b90400b2b99700a1b904003b

		var r2 Word
		q, r2 = z.divW(u, v[0])
		r = z2.setWord(r2)
		return
	}

	q, r = z.divLarge(z2, u, v)
	return
}

// divW returns q, r such that q = ⌊x/y⌋ and r = x%y = x - q·y.
// It uses z as the storage for q.
// Note that y is a single digit (Word), not a big number.
func (z nat) divW(x nat, y Word) (q nat, r Word) {
	m := len(x)
	switch {
	case y == 0:

//
// The iterative method processes n Words by n divW() calls, each of which visits every Word in the
// incrementally shortened q for a total of n + (n-1) + (n-2) ... + 2 + 1, or n(n+1)/2 divW()'s.
// Recursive conversion divides q by its approximate square root, yielding two parts, each half
// the size of q. Using the iterative method on both halves means 2 * (n/2)(n/2 + 1)/2 divW()'s

		return true
	case MULLW, MULLWCC, MULHW, MULHWCC, MULLD, MULLDCC, MULHD, MULHDCC, MULLWO, MULLWOCC, MULHWU, MULHWUCC, MULLDO, MULLDOCC:
		return true
	case DIVD, DIVDCC, DIVDU, DIVDUCC, DIVDE, DIVDECC, DIVDEU, DIVDEUCC, DIVDO, DIVDOCC, DIVDUO, DIVDUOCC:
		return true
	case MODUD, MODSD, MODUW, MODSW:
		return true
	case FADD, FADDS, FSUB, FSUBS, FMUL, FMULS, FDIV, FDIVS, FMADD, FMADDS, FMSUB, FMSUBS, FNMADD, FNMADDS, FNMSUB, FNMSUBS, FMULSCC:

		{name: "DIVWU", argLength: 2, reg: gp11div, asm: "DIVW", clobberFlags: true},              // arg0 / arg1

		{name: "MODL", argLength: 2, reg: gp11mod, asm: "IDIVL", aux: "Bool", clobberFlags: true}, // arg0 % arg1
		{name: "MODW", argLength: 2, reg: gp11mod, asm: "IDIVW", aux: "Bool", clobberFlags: true}, // arg0 % arg1

		{name: "DIVD", argLength: 2, reg: gp21, asm: "DIVD", typ: "Int64"},   // arg0/arg1 (signed 64-bit)
		{name: "DIVW", argLength: 2, reg: gp21, asm: "DIVW", typ: "Int32"},   // arg0/arg1 (signed 32-bit)
		{name: "DIVDU", argLength: 2, reg: gp21, asm: "DIVDU", typ: "Int64"}, // arg0/arg1 (unsigned 64-bit)
		{name: "DIVWU", argLength: 2, reg: gp21, asm: "DIVWU", typ: "Int32"}, // arg0/arg1 (unsigned 32-bit)

(Div(64|32)F ...) => (FDIV(D|S) ...)

(Div64 x y [false])  => (DIV x y)
(Div64u ...) => (DIVU ...)
(Div32 x y [false])  => (DIVW x y)
(Div32u ...) => (DIVUW ...)
(Div16 x y [false])  => (DIVW  (SignExt16to32 x) (SignExt16to32 y))
(Div16u x y) => (DIVUW (ZeroExt16to32 x) (ZeroExt16to32 y))
(Div8 x y)   => (DIVW  (SignExt8to32 x)  (SignExt8to32 y))
(Div8u x y)  => (DIVUW (ZeroExt8to32 x)  (ZeroExt8to32 y))

(Hmul64 ...)  => (MULH  ...)

		rec := reciprocalWord(test.y)
		q, r := divWW(test.x1, test.x0, test.y, rec)
		if q != test.q || r != test.r {
			t.Errorf("#%d got (%x, %x) want (%x, %x)", i, q, r, test.q, test.r)
		}
	}
	//random tests
	for ; i < testsNumber; i++ {
		x1 := rndW()
		x0 := rndW()
		y := rndW()
		if x1 >= y {
			continue
		}
		rec := reciprocalWord(y)
		qGot, rGot := divWW(x1, x0, y, rec)

	"CVTTSS2SQ",
	"CWD",
	"CWDE",
	"DAA",
	"DAS",
	"DECB",
	"DECL",
	"DECQ",
	"DECW",
	"DIVB",
	"DIVL",
	"DIVPD",
	"DIVPS",
	"DIVQ",
	"DIVSD",
	"DIVSS",
	"DIVW",
	"DPPD",
	"DPPS",
	"EMMS",
	"ENTER",
	"EXTRACTPS",
	"F2XM1",
	"FABS",
	"FADDD",
	"FADDDP",
	"FADDF",
	"FADDL",
	"FADDW",
	"FBLD",
	"FBSTP",
	"FCHS",
	"FCLEX",

		{name: "DIV", argLength: 2, reg: gp21, asm: "DIV", typ: "Int64"}, // arg0 / arg1
		{name: "DIVU", argLength: 2, reg: gp21, asm: "DIVU", typ: "UInt64"},
		{name: "DIVW", argLength: 2, reg: gp21, asm: "DIVW", typ: "Int32"},
		{name: "DIVUW", argLength: 2, reg: gp21, asm: "DIVUW", typ: "UInt32"},
		{name: "REM", argLength: 2, reg: gp21, asm: "REM", typ: "Int64"}, // arg0 % arg1