var originals []ir.Node
	var walk func(n ir.Node)
	walk = func(n ir.Node) {
		switch n.Op() {
		case ir.OADD:
			n := n.(*ir.BinaryExpr)
			walk(n.X)
			walk(n.Y)
		case ir.OSUB, ir.OANDNOT:
			n := n.(*ir.BinaryExpr)
			walk(n.X)
		case ir.OCONVNOP:
			n := n.(*ir.ConvExpr)
			if n.X.Type().IsUnsafePtr() {
				n.X = cheapExpr(n.X, init)

		x := v_0.Args[0]
		if !(is32Bit(-c)) {
			break
		}
		v.reset(OpPPC64ADDconst)
		v.AuxInt = int64ToAuxInt(-c)
		v.AddArg(x)
		return true
	}
	// match: (NEG (SUB x y))
	// result: (SUB y x)
	for {
		if v_0.Op != OpPPC64SUB {
			break
		}
		y := v_0.Args[1]
		x := v_0.Args[0]
		v.reset(OpPPC64SUB)
		v.AddArg2(y, x)
		return true
	}

		}
	}

	// Test that Sub uses the method when present.
	sub, err := Sub(subOnly{testFsys}, "sub")
	check("subOnly", sub, err)

	// Test that Sub uses Open when the method is not present.
	sub, err = Sub(openOnly{testFsys}, "sub")
	check("openOnly", sub, err)

	_, err = sub.Open("nonexist")
	if err == nil {
		t.Fatal("Open(nonexist): succeeded")
	}

	{"SubShift32", testSubShift32},
}

var crBenches = []struct {
	name string
	bf   func(b *testing.B)
}{
	{"SoloJump", benchSoloJump},
	{"CombJump", benchCombJump},
}

// Test int32/int64's add/sub/madd/msub operations with boundary values to
// ensure the optimization to 'comparing to zero' expressions of if-statements
// yield expected results.
// 32 rewriting rules are covered. At least two scenarios for "Canonicalize

		// order as they are in the specification: RS1, RS2, RS3, RD.
		ins.rs1, ins.rs2 = ins.rs2, ins.rs1

	case ANEG, ANEGW:
		// NEG rs, rd -> SUB rs, X0, rd
		ins.as = ASUB
		if p.As == ANEGW {
			ins.as = ASUBW
		}
		ins.rs1 = REG_ZERO
		if ins.rd == obj.REG_NONE {
			ins.rd = ins.rs2
		}

	case ANOT:
		// NOT rs, rd -> XORI $-1, rs, rd

	'Y': true, 'Z': true,

	'!':  true, // sub-delims
	'$':  true, // sub-delims
	'%':  true, // pct-encoded (and used in IPv6 zones)
	'&':  true, // sub-delims
	'(':  true, // sub-delims
	')':  true, // sub-delims
	'*':  true, // sub-delims
	'+':  true, // sub-delims
	',':  true, // sub-delims
	'-':  true, // unreserved
	'.':  true, // unreserved

	{AMOVWU, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 14, 8, 0, NOTUSETMP},

	{ASUB, C_REG, C_REG, C_NONE, C_REG, C_NONE, 2, 4, 0, 0},
	{ASUBV, C_REG, C_REG, C_NONE, C_REG, C_NONE, 2, 4, 0, 0},
	{AADD, C_REG, C_REG, C_NONE, C_REG, C_NONE, 2, 4, 0, 0},
	{AADDV, C_REG, C_REG, C_NONE, C_REG, C_NONE, 2, 4, 0, 0},
	{AAND, C_REG, C_REG, C_NONE, C_REG, C_NONE, 2, 4, 0, 0},
	{ASUB, C_REG, C_NONE, C_NONE, C_REG, C_NONE, 2, 4, 0, 0},

		{
			repo:   gitrepo1,
			rev:    "v3",
			subdir: "v3/sub/dir",
			files: map[string]uint64{
				"prefix/":                    0,
				"prefix/v3/":                 0,
				"prefix/v3/sub/":             0,
				"prefix/v3/sub/dir/":         0,
				"prefix/v3/sub/dir/file.txt": 16,
			},
		},
		{
			repo:   hgrepo1,
			rev:    "v3",
			subdir: "v3/sub/dir",
			files: map[string]uint64{

			p.From.Type = obj.TYPE_MEM
			p.From.Sym = ctxt.Int64Sym(p.From.Offset)
			p.From.Name = obj.NAME_EXTERN
			p.From.Offset = 0
		}
	}

	// Rewrite SUB constants into ADD.
	switch p.As {
	case ASUB:
		if p.From.Type == obj.TYPE_CONST {
			p.From.Offset = -p.From.Offset
			p.As = AADD
		}

	case ASUBU:
		if p.From.Type == obj.TYPE_CONST {
			p.From.Offset = -p.From.Offset

	y3.Add(t0, t2)                               // Y3 := t0 + t2
	y3.Sub(x3, y3)                               // Y3 := X3 - Y3
	z3 := new(fiat.P384Element).Mul(p384B(), t2) // Z3 := b * t2
	x3.Sub(y3, z3)                               // X3 := Y3 - Z3
	z3.Add(x3, x3)                               // Z3 := X3 + X3
	x3.Add(x3, z3)                               // X3 := X3 + Z3
	z3.Sub(t1, x3)                               // Z3 := t1 - X3