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/****************************************************************

The author of this software is David M. Gay.

Copyright (C) 1998-2001 by Lucent Technologies

All Rights Reserved

Permission to use, copy, modify, and distribute this software and

its documentation for any purpose and without fee is hereby

granted, provided that the above copyright notice appear in all

copies and that both that the copyright notice and this

permission notice and warranty disclaimer appear in supporting

documentation, and that the name of Lucent or any of its entities

not be used in advertising or publicity pertaining to

distribution of the software without specific, written prior

permission.

LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,

INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.

IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY

SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER

IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,

ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF

THIS SOFTWARE.

****************************************************************/

/* Please send bug reports to David M. Gay (dmg at acm dot org,

 * with " at " changed at "@" and " dot " changed to ".").	*/

#include <_ansi.h>

#include 

#include 

#include 

#include "mprec.h"

#include "gdtoa.h"

#include "gd_qnan.h"

#include "locale.h"

#if defined (_HAVE_LONG_DOUBLE) && !defined (_LDBL_EQ_DBL)

#define USE_LOCALE

 static const int

fivesbits[] = {	 0,  3,  5,  7, 10, 12, 14, 17, 19, 21,

		24, 26, 28, 31, 33, 35, 38, 40, 42, 45,

		47, 49, 52

#ifdef VAX

		, 54, 56

#endif

		};

static _Bigint *

#ifdef KR_headers

sum(p, a, b) struct _reent *p; _Bigint *a; _Bigint *b;

#else

sum(struct _reent *p, _Bigint *a, _Bigint *b)

#endif

{

	_Bigint *c;

	__ULong carry, *xc, *xa, *xb, *xe, y;

#ifdef Pack_32

	__ULong z;

#endif

	if (a->_wds < b->_wds) {

		c = b; b = a; a = c;

		}

	c = Balloc(p, a->_k);

	c->_wds = a->_wds;

	carry = 0;

	xa = a->_x;

	xb = b->_x;

	xc = c->_x;

	xe = xc + b->_wds;

#ifdef Pack_32

	do {

		y = (*xa & 0xffff) + (*xb & 0xffff) + carry;

		carry = (y & 0x10000) >> 16;

		z = (*xa++ >> 16) + (*xb++ >> 16) + carry;

		carry = (z & 0x10000) >> 16;

		Storeinc(xc, z, y);

		}

		while(xc < xe);

	xe += a->_wds - b->_wds;

	while(xc < xe) {

		y = (*xa & 0xffff) + carry;

		carry = (y & 0x10000) >> 16;

		z = (*xa++ >> 16) + carry;

		carry = (z & 0x10000) >> 16;

		Storeinc(xc, z, y);

		}

#else

	do {

		y = *xa++ + *xb++ + carry;

		carry = (y & 0x10000) >> 16;

		*xc++ = y & 0xffff;

		}

		while(xc < xe);

	xe += a->_wds - b->_wds;

	while(xc < xe) {

		y = *xa++ + carry;

		carry = (y & 0x10000) >> 16;

		*xc++ = y & 0xffff;

		}

#endif

	if (carry) {

		if (c->_wds == c->_maxwds) {

			b = Balloc(p, c->_k + 1);

			Bcopy(b, c);

			Bfree(p, c);

			c = b;

			}

		c->_x[c->_wds++] = 1;

		}

	return c;

	}

static void

#ifdef KR_headers

rshift(b, k) _Bigint *b; int k;

#else

rshift(_Bigint *b, int k)

#endif

{

	__ULong *x, *x1, *xe, y;

	int n;

	x = x1 = b->_x;

	n = k >> kshift;

	if (n < b->_wds) {

		xe = x + b->_wds;

		x += n;

		if (k &= kmask) {

			n = ULbits - k;

			y = *x++ >> k;

			while(x < xe) {

				*x1++ = (y | (*x << n)) & ALL_ON;

				y = *x++ >> k;

				}

			if ((*x1 = y) !=0)

				x1++;

			}

		else

			while(x < xe)

				*x1++ = *x++;

		}

	if ((b->_wds = x1 - b->_x) == 0)

		b->_x[0] = 0;

	}

static int

#ifdef KR_headers

trailz(b) _Bigint *b;

#else

trailz(_Bigint *b)

#endif

{

	__ULong L, *x, *xe;

	int n = 0;

	x = b->_x;

	xe = x + b->_wds;

	for(n = 0; x < xe && !*x; x++)

		n += ULbits;

	if (x < xe) {

		L = *x;

		n += lo0bits(&L);

		}

	return n;

	}

 _Bigint *

#ifdef KR_headers

increment(p, b) struct _reent *p; _Bigint *b;

#else

increment(struct _reent *p, _Bigint *b)

#endif

{

	__ULong *x, *xe;

	_Bigint *b1;

#ifdef Pack_16

	__ULong carry = 1, y;

#endif

	x = b->_x;

	xe = x + b->_wds;

#ifdef Pack_32

	do {

		if (*x < (__ULong)0xffffffffL) {

			++*x;

			return b;

			}

		*x++ = 0;

		} while(x < xe);

#else

	do {

		y = *x + carry;

		carry = y >> 16;

		*x++ = y & 0xffff;

		if (!carry)

			return b;

		} while(x < xe);

	if (carry)

#endif

	{

		if (b->_wds >= b->_maxwds) {

			b1 = Balloc(p,b->_k+1);

			Bcopy(b1,b);

			Bfree(p,b);

			b = b1;

			}

		b->_x[b->_wds++] = 1;

		}

	return b;

	}

 int

#ifdef KR_headers

decrement(b) _Bigint *b;

#else

decrement(_Bigint *b)

#endif

{

	__ULong *x, *xe;

#ifdef Pack_16

	__ULong borrow = 1, y;

#endif

	x = b->_x;

	xe = x + b->_wds;

#ifdef Pack_32

	do {

		if (*x) {

			--*x;

			break;

			}

		*x++ = 0xffffffffL;

		}

		while(x < xe);

#else

	do {

		y = *x - borrow;

		borrow = (y & 0x10000) >> 16;

		*x++ = y & 0xffff;

		} while(borrow && x < xe);

#endif

	return STRTOG_Inexlo;

	}

 static int

#ifdef KR_headers

all_on(b, n) _Bigint *b; int n;

#else

all_on(_Bigint *b, int n)

#endif

{

	__ULong *x, *xe;

	x = b->_x;

	xe = x + (n >> kshift);

	while(x < xe)

		if ((*x++ & ALL_ON) != ALL_ON)

			return 0;

	if (n &= kmask)

		return ((*x | (ALL_ON << n)) & ALL_ON) == ALL_ON;

	return 1;

	}

 _Bigint *

#ifdef KR_headers

set_ones(p, b, n) struct _reent *p; _Bigint *b; int n;

#else

set_ones(struct _reent *p, _Bigint *b, int n)

#endif

{

	int k;

	__ULong *x, *xe;

	k = (n + ((1 << kshift) - 1)) >> kshift;

	if (b->_k < k) {

		Bfree(p,b);

		b = Balloc(p,k);

		}

	k = n >> kshift;

	if (n &= kmask)

		k++;

	b->_wds = k;

	x = b->_x;

	xe = x + k;

	while(x < xe)

		*x++ = ALL_ON;

	if (n)

		x[-1] >>= ULbits - n;

	return b;

	}

 static int

rvOK

#ifdef KR_headers

 (p, d, fpi, exp, bits, exact, rd, irv)

 struct _reent *p; double d; FPI *fpi; Long *exp; __ULong *bits; int exact, rd, *irv;

#else

 (struct _reent *p, double d, FPI *fpi, Long *exp, __ULong *bits, int exact, int rd, int *irv)

#endif

{

	_Bigint *b;

	__ULong carry, inex, lostbits;

	int bdif, e, j, k, k1, nb, rv;

	carry = rv = 0;

	b = d2b(p, d, &e, &bdif);

	bdif -= nb = fpi->nbits;

	e += bdif;

	if (bdif <= 0) {

		if (exact)

			goto trunc;

		goto ret;

		}

	if (P == nb) {

		if (

#ifndef IMPRECISE_INEXACT

			exact &&

#endif

			fpi->rounding ==

#ifdef RND_PRODQUOT

					FPI_Round_near

#else

					Flt_Rounds

#endif

			) goto trunc;

		goto ret;

		}

	switch(rd) {

	  case 1:

		goto trunc;

	  case 2:

		break;

	  default: /* round near */

		k = bdif - 1;

		if (k < 0)

			goto trunc;

		if (!k) {

			if (!exact)

				goto ret;

			if (b->_x[0] & 2)

				break;

			goto trunc;

			}

		if (b->_x[k>>kshift] & ((__ULong)1 << (k & kmask)))

			break;

		goto trunc;

	  }

	/* "break" cases: round up 1 bit, then truncate; bdif > 0 */

	carry = 1;

 trunc:

	inex = lostbits = 0;

	if (bdif > 0) {

		if ( (lostbits = any_on(b, bdif)) !=0)

			inex = STRTOG_Inexlo;

		rshift(b, bdif);

		if (carry) {

			inex = STRTOG_Inexhi;

			b = increment(p, b);

			if ( (j = nb & kmask) !=0)

				j = ULbits - j;

			if (hi0bits(b->_x[b->_wds - 1]) != j) {

				if (!lostbits)

					lostbits = b->_x[0] & 1;

				rshift(b, 1);

				e++;

				}

			}

		}

	else if (bdif < 0)

		b = lshift(p, b, -bdif);

	if (e < fpi->emin) {

		k = fpi->emin - e;

		e = fpi->emin;

		if (k > nb || fpi->sudden_underflow) {

			b->_wds = inex = 0;

			*irv = STRTOG_Underflow | STRTOG_Inexlo;

			}

		else {

			k1 = k - 1;

			if (k1 > 0 && !lostbits)

				lostbits = any_on(b, k1);

			if (!lostbits && !exact)

				goto ret;

			lostbits |=

			  carry = b->_x[k1>>kshift] & (1 << (k1 & kmask));

			rshift(b, k);

			*irv = STRTOG_Denormal;

			if (carry) {

				b = increment(p, b);

				inex = STRTOG_Inexhi | STRTOG_Underflow;

				}

			else if (lostbits)

				inex = STRTOG_Inexlo | STRTOG_Underflow;

			}

		}

	else if (e > fpi->emax) {

		e = fpi->emax + 1;

		*irv = STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;

#ifndef NO_ERRNO

		errno = ERANGE;

#endif

		b->_wds = inex = 0;

		}

	*exp = e;

	copybits(bits, nb, b);

	*irv |= inex;

	rv = 1;

 ret:

	Bfree(p,b);

	return rv;

	}

 static int

#ifdef KR_headers

mantbits(d) double d;

#else

mantbits(U d)

#endif

{

	__ULong L;

#ifdef VAX

	L = word1(d) << 16 | word1(d) >> 16;

	if (L)

#else

	if ( (L = word1(d)) !=0)

#endif

		return P - lo0bits(&L);

#ifdef VAX

	L = word0(d) << 16 | word0(d) >> 16 | Exp_msk11;

#else

	L = word0(d) | Exp_msk1;

#endif

	return P - 32 - lo0bits(&L);

	}

 int

_strtodg_r

#ifdef KR_headers

	(p, s00, se, fpi, exp, bits)

	struct _reent *p; const char *s00; char **se; FPI *fpi; Long *exp; __ULong *bits;

#else

	(struct _reent *p, const char *s00, char **se, FPI *fpi, Long *exp, __ULong *bits)

#endif

{

	int abe, abits, asub;

	int bb0, bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, denorm;

	int dsign, e, e1, e2, emin, esign, finished, i, inex, irv;

	int j, k, nbits, nd, nd0, nf, nz, nz0, rd, rvbits, rve, rve1, sign;

	int sudden_underflow;

	const char *s, *s0, *s1;

	//double adj, adj0, rv, tol;

	double adj0, tol;

	U adj, rv;

	Long L;

	__ULong y, z;

	_Bigint *ab, *bb, *bb1, *bd, *bd0, *bs, *delta, *rvb, *rvb0;

	irv = STRTOG_Zero;

	denorm = sign = nz0 = nz = 0;

	dval(rv) = 0.;

	rvb = 0;

	nbits = fpi->nbits;

	for(s = s00;;s++) switch(*s) {

		case '-':

			sign = 1;

			/* no break */

		case '+':

			if (*++s)

				goto break2;

			/* no break */

		case 0:

			sign = 0;

			irv = STRTOG_NoNumber;

			s = s00;

			goto ret;

		case '\t':

		case '\n':

		case '\v':

		case '\f':

		case '\r':

		case ' ':

			continue;

		default:

			goto break2;

		}

 break2:

	if (*s == '0') {

#ifndef NO_HEX_FP

		switch(s[1]) {

		  case 'x':

		  case 'X':

			irv = gethex(p, &s, fpi, exp, &rvb, sign);

			if (irv == STRTOG_NoNumber) {

				s = s00;

				sign = 0;

				}

			goto ret;

		  }

#endif

		nz0 = 1;

		while(*++s == '0') ;

		if (!*s)

			goto ret;

		}

	sudden_underflow = fpi->sudden_underflow;

	s0 = s;

	y = z = 0;

	for(decpt = nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)

		if (nd < 9)

			y = 10*y + c - '0';

		else if (nd < 16)

			z = 10*z + c - '0';

	nd0 = nd;

#ifdef USE_LOCALE

	if (strncmp (s, _localeconv_r (p)->decimal_point,

		     strlen (_localeconv_r (p)->decimal_point)) == 0)

#else

	if (c == '.')

#endif

		{

		decpt = 1;

#ifdef USE_LOCALE

		c = *(s += strlen (_localeconv_r (p)->decimal_point));

#else

		c = *++s;

#endif

		if (!nd) {

			for(; c == '0'; c = *++s)

				nz++;

			if (c > '0' && c <= '9') {

				s0 = s;

				nf += nz;

				nz = 0;

				goto have_dig;

				}

			goto dig_done;

			}

		for(; c >= '0' && c <= '9'; c = *++s) {

 have_dig:

			nz++;

			if (c -= '0') {

				nf += nz;

				for(i = 1; i < nz; i++)

					if (nd++ < 9)

						y *= 10;

					else if (nd <= DBL_DIG + 1)

						z *= 10;

				if (nd++ < 9)

					y = 10*y + c;

				else if (nd <= DBL_DIG + 1)

					z = 10*z + c;

				nz = 0;

				}

			}

		}

 dig_done:

	e = 0;

	if (c == 'e' || c == 'E') {

		if (!nd && !nz && !nz0) {

			irv = STRTOG_NoNumber;

			s = s00;

			goto ret;

			}

		s00 = s;

		esign = 0;

		switch(c = *++s) {

			case '-':

				esign = 1;

			case '+':

				c = *++s;

			}

		if (c >= '0' && c <= '9') {

			while(c == '0')

				c = *++s;

			if (c > '0' && c <= '9') {

				L = c - '0';

				s1 = s;

				while((c = *++s) >= '0' && c <= '9')

					L = 10*L + c - '0';

				if (s - s1 > 8 || L > 19999)

					/* Avoid confusion from exponents

					 * so large that e might overflow.

					 */

					e = 19999; /* safe for 16 bit ints */

				else

					e = (int)L;

				if (esign)

					e = -e;

				}

			else

				e = 0;

			}

		else

			s = s00;

		}

	if (!nd) {

		if (!nz && !nz0) {

#ifdef INFNAN_CHECK

			/* Check for Nan and Infinity */

			if (!decpt)

			 switch(c) {

			  case 'i':

			  case 'I':

				if (match(&s,"nf")) {

					--s;

					if (!match(&s,"inity"))

						++s;

					irv = STRTOG_Infinite;

					goto infnanexp;

					}

				break;

			  case 'n':

			  case 'N':

				if (match(&s, "an")) {

					irv = STRTOG_NaN;

					*exp = fpi->emax + 1;

#ifndef No_Hex_NaN

					if (*s == '(') /*)*/

						irv = hexnan(&s, fpi, bits);

#endif

					goto infnanexp;

					}

			  }

#endif /* INFNAN_CHECK */

			irv = STRTOG_NoNumber;

			s = s00;

			}

		goto ret;

		}

	irv = STRTOG_Normal;

	e1 = e -= nf;

	rd = 0;

	switch(fpi->rounding & 3) {

	  case FPI_Round_up:

		rd = 2 - sign;

		break;

	  case FPI_Round_zero:

		rd = 1;

		break;

	  case FPI_Round_down:

		rd = 1 + sign;

	  }

	/* Now we have nd0 digits, starting at s0, followed by a

	 * decimal point, followed by nd-nd0 digits.  The number we're

	 * after is the integer represented by those digits times

	 * 10**e */

	if (!nd0)

		nd0 = nd;

	k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;

	dval(rv) = y;

	if (k > 9)

		dval(rv) = tens[k - 9] * dval(rv) + z;

	bd0 = 0;

	if (nbits <= P && nd <= DBL_DIG) {

		if (!e) {

			if (rvOK(p, dval(rv), fpi, exp, bits, 1, rd, &irv))

				goto ret;

			}

		else if (e > 0) {

			if (e <= Ten_pmax) {

#ifdef VAX

				goto vax_ovfl_check;

#else

				i = fivesbits[e] + mantbits(rv) <= P;

				/* rv = */ rounded_product(dval(rv), tens[e]);

				if (rvOK(p, dval(rv), fpi, exp, bits, i, rd, &irv))

					goto ret;

				e1 -= e;

				goto rv_notOK;

#endif

				}

			i = DBL_DIG - nd;

			if (e <= Ten_pmax + i) {

				/* A fancier test would sometimes let us do

				 * this for larger i values.

				 */

				e2 = e - i;

				e1 -= i;

				dval(rv) *= tens[i];

#ifdef VAX

				/* VAX exponent range is so narrow we must

				 * worry about overflow here...

				 */

 vax_ovfl_check:

				dval(adj) = dval(rv);

				word0(adj) -= P*Exp_msk1;

				/* adj = */ rounded_product(dval(adj), tens[e2]);

				if ((word0(adj) & Exp_mask)

				 > Exp_msk1*(DBL_MAX_EXP+Bias-1-P))

					goto rv_notOK;

				word0(adj) += P*Exp_msk1;

				dval(rv) = dval(adj);

#else

				/* rv = */ rounded_product(dval(rv), tens[e2]);

#endif

				if (rvOK(p, dval(rv), fpi, exp, bits, 0, rd, &irv))

					goto ret;

				e1 -= e2;

				}

			}

#ifndef Inaccurate_Divide

		else if (e >= -Ten_pmax) {

			/* rv = */ rounded_quotient(dval(rv), tens[-e]);

			if (rvOK(p, dval(rv), fpi, exp, bits, 0, rd, &irv))

				goto ret;

			e1 -= e;

			}

#endif

		}

 rv_notOK:

	e1 += nd - k;

	/* Get starting approximation = rv * 10**e1 */

	e2 = 0;

	if (e1 > 0) {

		if ( (i = e1 & 15) !=0)

			dval(rv) *= tens[i];

		if (e1 &= ~15) {

			e1 >>= 4;

			while(e1 >= (1 << n_bigtens-1)) {

				e2 += ((word0(rv) & Exp_mask)

					>> Exp_shift1) - Bias;

				word0(rv) &= ~Exp_mask;

				word0(rv) |= Bias << Exp_shift1;

				dval(rv) *= bigtens[n_bigtens-1];

				e1 -= 1 << n_bigtens-1;

				}

			e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias;

			word0(rv) &= ~Exp_mask;

			word0(rv) |= Bias << Exp_shift1;

			for(j = 0; e1 > 0; j++, e1 >>= 1)

				if (e1 & 1)

					dval(rv) *= bigtens[j];

			}

		}

	else if (e1 < 0) {

		e1 = -e1;

		if ( (i = e1 & 15) !=0)

			dval(rv) /= tens[i];

		if (e1 &= ~15) {

			e1 >>= 4;

			while(e1 >= (1 << n_bigtens-1)) {

				e2 += ((word0(rv) & Exp_mask)

					>> Exp_shift1) - Bias;

				word0(rv) &= ~Exp_mask;

				word0(rv) |= Bias << Exp_shift1;

				dval(rv) *= tinytens[n_bigtens-1];

				e1 -= 1 << n_bigtens-1;

				}

			e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias;

			word0(rv) &= ~Exp_mask;

			word0(rv) |= Bias << Exp_shift1;

			for(j = 0; e1 > 0; j++, e1 >>= 1)

				if (e1 & 1)

					dval(rv) *= tinytens[j];

			}

		}

#ifdef IBM

	/* e2 is a correction to the (base 2) exponent of the return

	 * value, reflecting adjustments above to avoid overflow in the

	 * native arithmetic.  For native IBM (base 16) arithmetic, we

	 * must multiply e2 by 4 to change from base 16 to 2.

	 */

	e2 <<= 2;

#endif

	rvb = d2b(p, dval(rv), &rve, &rvbits);	/* rv = rvb * 2^rve */

	rve += e2;

	if ((j = rvbits - nbits) > 0) {

		rshift(rvb, j);

		rvbits = nbits;

		rve += j;

		}

	bb0 = 0;	/* trailing zero bits in rvb */

	e2 = rve + rvbits - nbits;

	if (e2 > fpi->emax + 1)

		goto huge;

	rve1 = rve + rvbits - nbits;

	if (e2 < (emin = fpi->emin)) {

		denorm = 1;

		j = rve - emin;

		if (j > 0) {

			rvb = lshift(p, rvb, j);

			rvbits += j;

			}

		else if (j < 0) {

			rvbits += j;

			if (rvbits <= 0) {

				if (rvbits < -1) {

 ufl:

					rvb->_wds = 0;

					rvb->_x[0] = 0;

					*exp = emin;

					irv = STRTOG_Underflow | STRTOG_Inexlo;

					goto ret;

					}

				rvb->_x[0] = rvb->_wds = rvbits = 1;

				}

			else

				rshift(rvb, -j);

			}

		rve = rve1 = emin;

		if (sudden_underflow && e2 + 1 < emin)

			goto ufl;

		}

	/* Now the hard part -- adjusting rv to the correct value.*/

	/* Put digits into bd: true value = bd * 10^e */

	bd0 = s2b(p, s0, nd0, nd, y);

	for(;;) {

		bd = Balloc(p,bd0->_k);

		Bcopy(bd, bd0);

		bb = Balloc(p,rvb->_k);

		Bcopy(bb, rvb);

		bbbits = rvbits - bb0;

		bbe = rve + bb0;

		bs = i2b(p, 1);

		if (e >= 0) {

			bb2 = bb5 = 0;

			bd2 = bd5 = e;

			}

		else {

			bb2 = bb5 = -e;

			bd2 = bd5 = 0;

			}

		if (bbe >= 0)

			bb2 += bbe;

		else

			bd2 -= bbe;

		bs2 = bb2;

		j = nbits + 1 - bbbits;

		i = bbe + bbbits - nbits;

		if (i < emin)	/* denormal */

			j += i - emin;

		bb2 += j;

		bd2 += j;

		i = bb2 < bd2 ? bb2 : bd2;

		if (i > bs2)

			i = bs2;

		if (i > 0) {

			bb2 -= i;

			bd2 -= i;

			bs2 -= i;

			}

		if (bb5 > 0) {

			bs = pow5mult(p, bs, bb5);

			bb1 = mult(p, bs, bb);

			Bfree(p,bb);

			bb = bb1;

			}

		bb2 -= bb0;

		if (bb2 > 0)

			bb = lshift(p, bb, bb2);

		else if (bb2 < 0)

			rshift(bb, -bb2);

		if (bd5 > 0)

			bd = pow5mult(p, bd, bd5);

		if (bd2 > 0)

			bd = lshift(p, bd, bd2);

		if (bs2 > 0)

			bs = lshift(p, bs, bs2);

		asub = 1;

		inex = STRTOG_Inexhi;

		delta = diff(p, bb, bd);

		if (delta->_wds <= 1 && !delta->_x[0])

			break;

		dsign = delta->_sign;

		delta->_sign = finished = 0;

		L = 0;

		i = cmp(delta, bs);

		if (rd && i <= 0) {

			irv = STRTOG_Normal;

			if ( (finished = dsign ^ (rd&1)) !=0) {

				if (dsign != 0) {

					irv |= STRTOG_Inexhi;

					goto adj1;

					}

				irv |= STRTOG_Inexlo;

				if (rve1 == emin)

					goto adj1;

				for(i = 0, j = nbits; j >= ULbits;

						i++, j -= ULbits) {

					if (rvb->_x[i] & ALL_ON)

						goto adj1;

					}

				if (j > 1 && lo0bits(rvb->_x + i) < j - 1)

					goto adj1;

				rve = rve1 - 1;

				rvb = set_ones(p, rvb, rvbits = nbits);

				break;

				}

			irv |= dsign ? STRTOG_Inexlo : STRTOG_Inexhi;

			break;

			}

		if (i < 0) {

			/* Error is less than half an ulp -- check for

			 * special case of mantissa a power of two.

			 */

			irv = dsign

				? STRTOG_Normal | STRTOG_Inexlo

				: STRTOG_Normal | STRTOG_Inexhi;

			if (dsign || bbbits > 1 || denorm || rve1 == emin)

				break;

			delta = lshift(p, delta,1);

			if (cmp(delta, bs) > 0) {

				irv = STRTOG_Normal | STRTOG_Inexlo;

				goto drop_down;

				}

			break;

			}

		if (i == 0) {

			/* exactly half-way between */

			if (dsign) {

				if (denorm && all_on(rvb, rvbits)) {

					/*boundary case -- increment exponent*/

					rvb->_wds = 1;

					rvb->_x[0] = 1;

					rve = emin + nbits - (rvbits = 1);

					irv = STRTOG_Normal | STRTOG_Inexhi;

					denorm = 0;

					break;

					}

				irv = STRTOG_Normal | STRTOG_Inexlo;

				}

			else if (bbbits == 1) {

				irv = STRTOG_Normal;

 drop_down:

				/* boundary case -- decrement exponent */

				if (rve1 == emin) {

					irv = STRTOG_Normal | STRTOG_Inexhi;

					if (rvb->_wds == 1 && rvb->_x[0] == 1)

						sudden_underflow = 1;

					break;

					}

				rve -= nbits;

				rvb = set_ones(p, rvb, rvbits = nbits);

				break;

				}

			else

				irv = STRTOG_Normal | STRTOG_Inexhi;

			if (bbbits < nbits && !denorm || !(rvb->_x[0] & 1))

				break;

			if (dsign) {

				rvb = increment(p, rvb);

				j = kmask & (ULbits - (rvbits & kmask));

				if (hi0bits(rvb->_x[rvb->_wds - 1]) != j)

					rvbits++;

				irv = STRTOG_Normal | STRTOG_Inexhi;

				}

			else {

				if (bbbits == 1)

					goto undfl;

				decrement(rvb);

				irv = STRTOG_Normal | STRTOG_Inexlo;

				}

			break;

			}

		if ((dval(adj) = ratio(delta, bs)) <= 2.) {

 adj1:

			inex = STRTOG_Inexlo;

			if (dsign) {

				asub = 0;

				inex = STRTOG_Inexhi;

				}

			else if (denorm && bbbits <= 1) {

 undfl:

				rvb->_wds = 0;

				rve = emin;

				irv = STRTOG_Underflow | STRTOG_Inexlo;

				break;

				}

			adj0 = dval(adj) = 1.;

			}

		else {

			adj0 = dval(adj) *= 0.5;

			if (dsign) {

				asub = 0;

				inex = STRTOG_Inexlo;

				}

			if (dval(adj) < 2147483647.) {

				L = adj0;

				adj0 -= L;

				switch(rd) {

				  case 0:

					if (adj0 >= .5)

						goto inc_L;

					break;

				  case 1:

					if (asub && adj0 > 0.)

						goto inc_L;

					break;

				  case 2:

					if (!asub && adj0 > 0.) {

 inc_L:

						L++;

						inex = STRTOG_Inexact - inex;

						}

				  }

				dval(adj) = L;

				}

			}

		y = rve + rvbits;

		/* adj *= ulp(dval(rv)); */

		/* if (asub) rv -= adj; else rv += adj; */

		if (!denorm && rvbits < nbits) {

			rvb = lshift(p, rvb, j = nbits - rvbits);

			rve -= j;

			rvbits = nbits;

			}

		ab = d2b(p, dval(adj), &abe, &abits);

		if (abe < 0)

			rshift(ab, -abe);

		else if (abe > 0)

			ab = lshift(p, ab, abe);

		rvb0 = rvb;

		if (asub) {

			/* rv -= adj; */

			j = hi0bits(rvb->_x[rvb->_wds-1]);

			rvb = diff(p, rvb, ab);

			k = rvb0->_wds - 1;

			if (denorm)

				/* do nothing */;

			else if (rvb->_wds <= k

				|| hi0bits( rvb->_x[k]) >

				   hi0bits(rvb0->_x[k])) {

				/* unlikely; can only have lost 1 high bit */

				if (rve1 == emin) {

					--rvbits;

					denorm = 1;

					}

				else {

					rvb = lshift(p, rvb, 1);

					--rve;

					--rve1;

					L = finished = 0;

					}

				}

			}

		else {

			rvb = sum(p, rvb, ab);

			k = rvb->_wds - 1;

			if (k >= rvb0->_wds

			 || hi0bits(rvb->_x[k]) < hi0bits(rvb0->_x[k])) {

				if (denorm) {

					if (++rvbits == nbits)

						denorm = 0;

					}

				else {

					rshift(rvb, 1);

					rve++;

					rve1++;

					L = 0;

					}

				}

			}

		Bfree(p,ab);

		Bfree(p,rvb0);

		if (finished)

			break;

		z = rve + rvbits;

		if (y == z && L) {

			/* Can we stop now? */

			tol = dval(adj) * 5e-16; /* > max rel error */

			dval(adj) = adj0 - .5;

			if (dval(adj) < -tol) {

				if (adj0 > tol) {

					irv |= inex;

					break;

					}

				}

			else if (dval(adj) > tol && adj0 < 1. - tol) {

				irv |= inex;

				break;

				}

			}

		bb0 = denorm ? 0 : trailz(rvb);

		Bfree(p,bb);

		Bfree(p,bd);

		Bfree(p,bs);

		Bfree(p,delta);

		}

	if (!denorm && (j = nbits - rvbits)) {

		if (j > 0)

			rvb = lshift(p, rvb, j);

		else

			rshift(rvb, -j);

		rve -= j;

		}

	*exp = rve;

	Bfree(p,bb);

	Bfree(p,bd);

	Bfree(p,bs);

	Bfree(p,bd0);

	Bfree(p,delta);

	if (rve > fpi->emax) {

 huge:

		rvb->_wds = 0;

		irv = STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;

#ifndef NO_ERRNO

		errno = ERANGE;

#endif

 infnanexp:

		*exp = fpi->emax + 1;

		}

 ret:

	if (denorm) {

		if (sudden_underflow) {

			rvb->_wds = 0;

			irv = STRTOG_Underflow | STRTOG_Inexlo;

			}

		else  {