if dead[node] {
			// Skip shift checks on unreachable nodes.
			return
		}

		switch node := node.(type) {
		case *ast.BinaryExpr:
			if node.Op == token.SHL || node.Op == token.SHR {
				checkLongShift(pass, node, node.X, node.Y)
			}
		case *ast.AssignStmt:
			if len(node.Lhs) != 1 || len(node.Rhs) != 1 {
				return
			}
			if node.Tok == token.SHL_ASSIGN || node.Tok == token.SHR_ASSIGN {

	mant := nat(nil).set(x.mant)
	exp := int(x.exp) - mant.bitLen()
	s := mant.bitLen() - int(x.prec+1)
	switch {
	case s < 0:
		mant = mant.shl(mant, uint(-s))
	case s > 0:
		mant = mant.shr(mant, uint(+s))
	}
	exp += s
	// x = mant * 2**exp with lsb(mant) == 1/2 ulp of x.prec

	// 2) Compute lower bound by subtracting 1/2 ulp.
	var lower decimal
	var tmp nat

      }

      while (!encodedCharBuffer.exhausted()) {
        val b = encodedCharBuffer.readByte().toInt() and 0xff
        writeByte('%'.code)
        writeByte(HEX_DIGITS[b shr 4 and 0xf].code)
        writeByte(HEX_DIGITS[b and 0xf].code)
      }
    } else {
      // This character doesn't need encoding. Just copy it over.
      writeUtf8CodePoint(codePoint)
    }

// The number n is known to be non-zero.
func (n nat) probablyPrimeMillerRabin(reps int, force2 bool) bool {
	nm1 := nat(nil).sub(n, natOne)
	// determine q, k such that nm1 = q << k
	k := nm1.trailingZeroBits()
	q := nat(nil).shr(nm1, k)

	nm3 := nat(nil).sub(nm1, natTwo)
	rand := rand.New(rand.NewSource(int64(n[0])))

	var x, y, quotient nat
	nm3Len := nm3.bitLen()

NextRandom:
	for i := 0; i < reps; i++ {

}

var optab = map[string]token.Token{
	"!": token.NOT,

	"+": token.ADD,
	"-": token.SUB,
	"*": token.MUL,
	"/": token.QUO,
	"%": token.REM,

	"<<": token.SHL,
	">>": token.SHR,

	"&":  token.AND,
	"|":  token.OR,
	"^":  token.XOR,
	"&^": token.AND_NOT,

	"==": token.EQL,
	"!=": token.NEQ,
	"<":  token.LSS,
	"<=": token.LEQ,
	">":  token.GTR,
	">=": token.GEQ,

        }
        else {
            this.acquires = null;
            this.releases = null;
        }
    }


    boolean matches ( String shr, String servc ) {
        return this.share.equalsIgnoreCase(shr) && ( servc == null || servc.startsWith("??") || this.service.equalsIgnoreCase(servc) );
    }


    @Override
    public boolean equals ( Object obj ) {

	MOVL	(index*4)(SI), AX; \
	BSWAPL	AX; \
	MOVL	AX, (index*4)(BP)

// Wt = SIGMA1(Wt-2) + Wt-7 + SIGMA0(Wt-15) + Wt-16; for 16 <= t <= 63
//   SIGMA0(x) = ROTR(7,x) XOR ROTR(18,x) XOR SHR(3,x)
//   SIGMA1(x) = ROTR(17,x) XOR ROTR(19,x) XOR SHR(10,x)
#define MSGSCHEDULE1(index) \
	MOVL	((index-2)*4)(BP), AX; \
	MOVL	AX, CX; \
	RORL	$17, AX; \
	MOVL	CX, DX; \
	RORL	$19, CX; \
	SHRL	$10, DX; \
	MOVL	((index-15)*4)(BP), BX; \

(SHR(Q|L) l:(MOV(Q|L)load [off] {sym} ptr mem) x) && buildcfg.GOAMD64 >= 3 && canMergeLoad(v, l) && clobber(l) => (SHRX(Q|L)load [off] {sym} ptr x mem)

((SHL|SHR|SAR)XQload [off] {sym} ptr (MOVQconst [c]) mem) => ((SHL|SHR|SAR)Qconst [int8(c&63)] (MOVQload [off] {sym} ptr mem))
((SHL|SHR|SAR)XQload [off] {sym} ptr (MOVLconst [c]) mem) => ((SHL|SHR|SAR)Qconst [int8(c&63)] (MOVQload [off] {sym} ptr mem))

	PUSH:      true,
	PUSHA:     true,
	RCL:       true,
	RCR:       true,
	ROL:       true,
	ROR:       true,
	SAR:       true,
	SBB:       true,
	SHL:       true,
	SHLD:      true,
	SHR:       true,
	SHRD:      true,
	SUB:       true,
	TEST:      true,
	XADD:      true,
	XCHG:      true,
	XOR:       true,
}

var plan9Reg = [...]string{
	AL:   "AL",
	CL:   "CL",

	{_Star, "*", Mul, precMul},
	{_Operator, "/", Div, precMul},
	{_Operator, "%", Rem, precMul},
	{_Operator, "&", And, precMul},
	{_Operator, "&^", AndNot, precMul},
	{_Operator, "<<", Shl, precMul},
	{_Operator, ">>", Shr, precMul},

	// assignment operations
	{_AssignOp, "+=", Add, precAdd},
	{_AssignOp, "-=", Sub, precAdd},
	{_AssignOp, "|=", Or, precAdd},
	{_AssignOp, "^=", Xor, precAdd},

	{_AssignOp, "*=", Mul, precMul},