/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Conversion from decimal to binary floating point
 */

#include "lint.h"
#include <stdlib.h>
#include "base_conversion.h"

/*
 * Convert the integer part of a nonzero base-10^4 _big_float *pd
 * to base 2^16 in **ppb.  The converted value is accurate to nsig
 * significant bits.  On exit, *sticky is nonzero if *pd had a
 * nonzero fractional part.  If pd->exponent > 0 and **ppb is not
 * large enough to hold the final converted value (i.e., the con-
 * verted significand scaled by 10^pd->exponent), then on exit,
 * *ppb will point to a newly allocated _big_float, which must be
 * freed by the caller.  (The number of significant bits we need
 * should fit in pb, but __big_float_times_power may allocate new
 * storage anyway because the exact product could require more than
 * 16000 bits.)
 *
 * This routine does not check that **ppb is large enough to hold
 * the result of converting the significand of *pd.
 */
static void
__big_decimal_to_big_binary(_big_float *pd, int nsig, _big_float **ppb,
    int *sticky)
{
        _big_float      *pb;
        int             i, j, len, s;
        unsigned int    carry;

        pb = *ppb;

        /* convert pd a digit at a time, most significant first */
        if (pd->bexponent + ((pd->blength - 1) << 2) >= 0) {
                pb->bsignificand[0] = pd->bsignificand[pd->blength - 1];
                len = 1;
                for (i = pd->blength - 2; i >= 0 &&
                    pd->bexponent + (i << 2) >= 0; i--) {
                        /* multiply pb by 10^4 and add next digit */
                        carry = pd->bsignificand[i];
                        for (j = 0; j < len; j++) {
                                carry += (unsigned int)pb->bsignificand[j]
                                    * 10000;
                                pb->bsignificand[j] = carry & 0xffff;
                                carry >>= 16;
                        }
                        if (carry)
                                pb->bsignificand[j++] = carry;
                        len = j;
                }
        } else {
                i = pd->blength - 1;
                len = 0;
        }

        /* convert any partial digit */
        if (i >= 0 && pd->bexponent + (i << 2) > -4) {
                s = pd->bexponent + (i << 2) + 4;
                /* multiply pb by 10^s and add partial digit */
                carry = pd->bsignificand[i];
                if (s == 1) {
                        s = carry % 1000;
                        carry = carry / 1000;
                        for (j = 0; j < len; j++) {
                                carry += (unsigned int)pb->bsignificand[j]
                                    * 10;
                                pb->bsignificand[j] = carry & 0xffff;
                                carry >>= 16;
                        }
                } else if (s == 2) {
                        s = carry % 100;
                        carry = carry / 100;
                        for (j = 0; j < len; j++) {
                                carry += (unsigned int)pb->bsignificand[j]
                                    * 100;
                                pb->bsignificand[j] = carry & 0xffff;
                                carry >>= 16;
                        }
                } else {
                        s = carry % 10;
                        carry = carry / 10;
                        for (j = 0; j < len; j++) {
                                carry += (unsigned int)pb->bsignificand[j]
                                    * 1000;
                                pb->bsignificand[j] = carry & 0xffff;
                                carry >>= 16;
                        }
                }
                if (carry)
                        pb->bsignificand[j++] = carry;
                len = j;
                i--;
        } else {
                s = 0;
        }

        pb->blength = len;
        pb->bexponent = 0;

        /* continue accumulating sticky flag */
        while (i >= 0)
                s |= pd->bsignificand[i--];
        *sticky = s;

        if (pd->bexponent > 0) {
                /* scale pb by 10^pd->exponent */
                __big_float_times_power(pb, 10, pd->bexponent, nsig, ppb);
        }
}

/*
 * Convert the decimal_record *pd to an unpacked datum *px accurately
 * enough that *px can be rounded correctly to sigbits significant bits.
 * (We may assume sigbits <= 113.)
 */
static void
__decimal_to_unpacked(unpacked *px, decimal_record *pd, int sigbits)
{
        _big_float      d, b, *pbd, *pbb;
        char            *ds;
        int             ids, i, ix, exp, ndigs;
        int             sticky, powtwo, sigdigits;

        px->sign = pd->sign;
        px->fpclass = pd->fpclass;
        ds = pd->ds;
        ndigs = pd->ndigits;
        exp = pd->exponent;

        /* remove trailing zeroes */
        while (ndigs > 0 && ds[ndigs - 1] == '0') {
                exp++;
                ndigs--;
        }
        if (ndigs < 1) {
                /* nothing left */
                px->fpclass = fp_zero;
                return;
        }

        /* convert remaining digits to a base-10^4 _big_float */
        d.bsize = _BIG_FLOAT_SIZE;
        d.bexponent = exp;
        d.blength = (ndigs + 3) >> 2;
        i = d.blength - 1;
        ids = ndigs - (d.blength << 2);
        switch (ids) {
        case -1:
                d.bsignificand[i] = 100 * ds[ids + 1] +
                    10 * ds[ids + 2] + ds[ids + 3] - 111 * '0';
                i--;
                ids += 4;
                break;

        case -2:
                d.bsignificand[i] = 10 * ds[ids + 2] + ds[ids + 3] - 11 * '0';
                i--;
                ids += 4;
                break;

        case -3:
                d.bsignificand[i] = ds[ids + 3] - '0';
                i--;
                ids += 4;
                break;
        }
        while (i >= 0) {
                d.bsignificand[i] = 1000 * ds[ids] + 100 * ds[ids + 1] +
                    10 * ds[ids + 2] + ds[ids + 3] - 1111 * '0';
                i--;
                ids += 4;
        }

        pbd = &d;
        powtwo = 0;

        /* pre-scale to get the bits we want into the integer part */
        if (exp < 0) {
                /* i is a lower bound on log10(x) */
                i = exp + ndigs - 1;
                if (i <= 0 || ((i * 217705) >> 16) < sigbits + 2) {
                        /*
                         * Scale by 2^(sigbits + 2 + u) where
                         * u is an upper bound on -log2(x).
                         */
                        powtwo = sigbits + 2;
                        if (i < 0)
                                powtwo += ((-i * 217706) + 65535) >> 16;
                        else if (i > 0)
                                powtwo -= (i * 217705) >> 16;
                        /*
                         * Take sigdigits large enough to get
                         * all integral digits correct.
                         */
                        sigdigits = i + 1 + (((powtwo * 19729) + 65535) >> 16);
                        __big_float_times_power(&d, 2, powtwo, sigdigits, &pbd);
                }
        }

        /* convert to base 2^16 */
        b.bsize = _BIG_FLOAT_SIZE;
        pbb = &b;
        __big_decimal_to_big_binary(pbd, sigbits + 2, &pbb, &sticky);

        /* adjust pbb->bexponent based on the scale factor above */
        pbb->bexponent -= powtwo;

        /* convert to unpacked */
        ix = 0;
        for (i = pbb->blength - 1; i > 0 && ix < 5; i -= 2) {
                px->significand[ix++] = (pbb->bsignificand[i] << 16) |
                    pbb->bsignificand[i - 1];
        }
        if (ix < 5) {
                /* pad with zeroes */
                if (i == 0)
                        px->significand[ix++] = pbb->bsignificand[i] << 16;
                while (ix < 5)
                        px->significand[ix++] = 0;
        } else {
                /* truncate and set a sticky bit if necessary */
                while (i >= 0 && pbb->bsignificand[i] == 0)
                        i--;
                if (i >= 0)
                        px->significand[4] |= 1;
        }
        if (sticky | pd->more)
                px->significand[4] |= 1;
        px->exponent = pbb->bexponent + (pbb->blength << 4) - 1;

        /* normalize so the most significant bit is set */
        while (px->significand[0] < 0x80000000u) {
                px->significand[0] = (px->significand[0] << 1) |
                    (px->significand[1] >> 31);
                px->significand[1] = (px->significand[1] << 1) |
                    (px->significand[2] >> 31);
                px->significand[2] = (px->significand[2] << 1) |
                    (px->significand[3] >> 31);
                px->significand[3] = (px->significand[3] << 1) |
                    (px->significand[4] >> 31);
                px->significand[4] <<= 1;
                px->exponent--;
        }

        if (pbd != &d)
                (void) free((void *)pbd);
        if (pbb != &b)
                (void) free((void *)pbb);
}

/*
 * Convert a string s consisting of n <= 18 ASCII decimal digits
 * to an integer value in double precision format, and set *pe
 * to the number of rounding errors incurred (0 or 1).
 */
static double
__digits_to_double(char *s, int n, int *pe)
{
        int     i, acc;
        double  t, th, tl;

        if (n <= 9) {
                acc = s[0] - '0';
                for (i = 1; i < n; i++) {
                        /* acc <- 10 * acc + next digit */
                        acc = (acc << 1) + (acc << 3) + s[i] - '0';
                }
                t = (double)acc;
                *pe = 0;
        } else {
                acc = s[0] - '0';
                for (i = 1; i < (n - 9); i++) {
                        /* acc <- 10 * acc + next digit */
                        acc = (acc << 1) + (acc << 3) + s[i] - '0';
                }
                th = 1.0e9 * (double)acc;       /* this will be exact */
                acc = s[n - 9] - '0';
                for (i = n - 8; i < n; i++) {
                        /* acc <- 10 * acc + next digit */
                        acc = (acc << 1) + (acc << 3) + s[i] - '0';
                }
                tl = (double)acc;
                /* add and indicate whether or not the sum is exact */
                t = th + tl;
                *pe = ((t - th) == tl)? 0 : 1;
        }
        return (t);
}

static union {
        int     i[2];
        double  d;
} C[] = {
#ifdef _LITTLE_ENDIAN
        { 0x00000000, 0x3cc40000 },
#else
        { 0x3cc40000, 0x00000000 },     /* 5 * 2^-53 */
#endif
};

#define five2m53        C[0].d

static int
__fast_decimal_to_single(single *px, decimal_mode *pm, decimal_record *pd,
    fp_exception_field_type *ps)
{
        double                  dds, delta, ddsplus, ddsminus, df1;
        int                     n, exp, rounded, e;
        float                   f1, f2;
        __ieee_flags_type       fb;

        if (pm->rd != fp_nearest)
                return (0);

        exp = pd->exponent;
        if (pd->ndigits <= 18) {
                rounded = 0;
                n = pd->ndigits;
        } else {
                rounded = 1;
                n = 18;
                exp += pd->ndigits - 18;
        }
        /*
         * exp must be in the range of the table, and the result
         * must not underflow or overflow.
         */
        if (exp < -__TBL_TENS_MAX || exp + n < -36 || exp + n > 38)
                return (0);

        __get_ieee_flags(&fb);
        dds = __digits_to_double(pd->ds, n, &e);
        if (e != 0)
                rounded = 1;
        if (exp > 0) {
                /* small positive exponent */
                if (exp > __TBL_TENS_EXACT)
                        rounded = 1;
                if (rounded) {
                        dds *= __tbl_tens[exp];
                } else {
                        dds = __mul_set(dds, __tbl_tens[exp], &e);
                        if (e)
                                rounded = 1;
                }
        } else if (exp < 0) {
                /* small negative exponent */
                if (-exp > __TBL_TENS_EXACT)
                        rounded = 1;
                if (rounded) {
                        dds /= __tbl_tens[-exp];
                } else {
                        dds = __div_set(dds, __tbl_tens[-exp], &e);
                        if (e)
                                rounded = 1;
                }
        }

        /*
         * At this point dds may have four rounding errors due to
         * (i) truncation of pd->ds to 18 digits, (ii) inexact con-
         * version of pd->ds to binary, (iii) scaling by a power of
         * ten that is not exactly representable, and (iv) roundoff
         * error in the multiplication.  Below we will incur one more
         * rounding error when we add or subtract delta and dds.  We
         * construct delta so that even after this last rounding error,
         * ddsplus is an upper bound on the exact value and ddsminus
         * is a lower bound.  Then as long as both of these quantities
         * round to the same single precision number, that number
         * will be the correctly rounded single precision result.
         * (If any rounding errors have been committed, then we must
         * also be certain that the result can't be exact.)
         */
        delta = five2m53 * dds;
        ddsplus = dds + delta;
        ddsminus = dds - delta;
        f1 = (float)(ddsplus);
        f2 = (float)(ddsminus);
        df1 = f1;
        __set_ieee_flags(&fb);
        if (f1 != f2)
                return (0);
        if (rounded) {
                /*
                 * If ddsminus <= f1 <= ddsplus, the result might be
                 * exact; we have to convert the long way to be sure.
                 */
                if (ddsminus <= df1 && df1 <= ddsplus)
                        return (0);
                *ps = (1 << fp_inexact);
        } else {
                *ps = (df1 == dds)? 0 : (1 << fp_inexact);
        }
        *px = (pd->sign)? -f1 : f1;
        return (1);
}

/*
 * Attempt conversion to double using floating-point arithmetic.
 * Return 1 if it works (at most one rounding error), 0 if it doesn't.
 */
static int
__fast_decimal_to_double(double *px, decimal_mode *pm, decimal_record *pd,
    fp_exception_field_type *ps)
{
        double                  dds;
        int                     e;
        __ieee_flags_type       fb;

        if (pm->rd != fp_nearest || pd->ndigits > 18 || pd->exponent
            > __TBL_TENS_EXACT || pd->exponent < -__TBL_TENS_EXACT)
                return (0);

        __get_ieee_flags(&fb);
        dds = __digits_to_double(pd->ds, pd->ndigits, &e);
        if (e != 0) {
                __set_ieee_flags(&fb);
                return (0);
        }
        if (pd->exponent > 0)
                dds = __mul_set(dds, __tbl_tens[pd->exponent], &e);
        else if (pd->exponent < 0)
                dds = __div_set(dds, __tbl_tens[-pd->exponent], &e);
        *px = (pd->sign)? -dds : dds;
        *ps = (e)? (1 << fp_inexact) : 0;
        __set_ieee_flags(&fb);
        return (1);
}

/* PUBLIC FUNCTIONS */

/*
 * The following routines convert the decimal record *pd to a floating
 * point value *px observing the rounding mode specified in pm->rd and
 * passing back any floating point exceptions that occur in *ps.
 *
 * pd->sign and pd->fpclass are always taken into account.  pd->exponent
 * and pd->ds are used when pd->fpclass is fp_normal or fp_subnormal.
 * In these cases, pd->ds must contain a null-terminated string of one
 * or more ASCII digits, the first of which is not zero, and pd->ndigits
 * must equal the length of this string.  If m is the integer represented
 * by the string pd->ds, then *px will be set to a correctly rounded
 * approximation to
 *
 *   -1**(pd->sign) * m * 10**(pd->exponent)
 *
 * (If pd->more != 0 then additional nonzero digits are assumed to follow
 * those in pd->ds, so m is effectively replaced by m + epsilon in the
 * expression above.)
 *
 * For example, if pd->exponent == -2 and pd->ds holds "1234", then *px
 * will be a correctly rounded approximation to 12.34.
 *
 * Note that the only mode that matters is the rounding direction pm->rd;
 * pm->df and pm->ndigits are never used.
 */

/* maximum decimal exponent we need to consider */
#define SINGLE_MAXE       47
#define DOUBLE_MAXE      326
#define EXTENDED_MAXE   4968
#define QUAD_MAXE       4968

void
decimal_to_single(single *px, decimal_mode *pm, decimal_record *pd,
    fp_exception_field_type *ps)
{
        single_equivalence      *kluge;
        unpacked                u;
        fp_exception_field_type ef;
        int                     i;

        /* special values */
        kluge = (single_equivalence *)px;
        switch (pd->fpclass) {
        case fp_zero:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0;
                kluge->f.msw.significand = 0;
                *ps = 0;
                return;

        case fp_infinity:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0xff;
                kluge->f.msw.significand = 0;
                *ps = 0;
                return;

        case fp_quiet:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0xff;
                kluge->f.msw.significand = 0x7fffff;
                *ps = 0;
                return;

        case fp_signaling:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0xff;
                kluge->f.msw.significand = 0x3fffff;
                *ps = 0;
                return;
        }

        /* numeric values */
        ef = 0;
        if (pd->exponent + pd->ndigits > SINGLE_MAXE) {
                /* result must overflow */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = 0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else if (pd->exponent + pd->ndigits < -SINGLE_MAXE) {
                /* result must underflow completely */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = -0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else {
                /* result may be in range */
                if (__fast_decimal_to_single(px, pm, pd, &ef) == 1) {
                        *ps = ef;
                        if (ef != 0)
                                __base_conversion_set_exception(ef);
                        return;
                }
                __decimal_to_unpacked(&u, pd, 24);
        }
        __pack_single(&u, px, pm->rd, &ef);
        *ps = ef;
        if (ef != 0)
                __base_conversion_set_exception(ef);
}

void
decimal_to_double(double *px, decimal_mode *pm, decimal_record *pd,
    fp_exception_field_type *ps)
{
        double_equivalence      *kluge;
        unpacked                u;
        fp_exception_field_type ef;
        int                     i;

        /* special values */
        kluge = (double_equivalence *)px;
        switch (pd->fpclass) {
        case fp_zero:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0;
                kluge->f.msw.significand = 0;
                kluge->f.significand2 = 0;
                *ps = 0;
                return;

        case fp_infinity:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7ff;
                kluge->f.msw.significand = 0;
                kluge->f.significand2 = 0;
                *ps = 0;
                return;

        case fp_quiet:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7ff;
                kluge->f.msw.significand = 0xfffff;
                kluge->f.significand2 = 0xffffffff;
                *ps = 0;
                return;

        case fp_signaling:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7ff;
                kluge->f.msw.significand = 0x7ffff;
                kluge->f.significand2 = 0xffffffff;
                *ps = 0;
                return;
        }

        /* numeric values */
        ef = 0;
        if (pd->exponent + pd->ndigits > DOUBLE_MAXE) {
                /* result must overflow */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = 0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else if (pd->exponent + pd->ndigits < -DOUBLE_MAXE) {
                /* result must underflow completely */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = -0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else {
                /* result may be in range */
                if (__fast_decimal_to_double(px, pm, pd, &ef) == 1) {
                        *ps = ef;
                        if (ef != 0)
                                __base_conversion_set_exception(ef);
                        return;
                }
                __decimal_to_unpacked(&u, pd, 53);
        }
        __pack_double(&u, px, pm->rd, &ef);
        *ps = ef;
        if (ef != 0)
                __base_conversion_set_exception(ef);
}

void
decimal_to_extended(extended *px, decimal_mode *pm, decimal_record *pd,
    fp_exception_field_type *ps)
{
        extended_equivalence    *kluge;
        unpacked                u;
        double_equivalence      dd;
        fp_exception_field_type ef;
        int                     i;

        /* special values */
        kluge = (extended_equivalence *)px;
        switch (pd->fpclass) {
        case fp_zero:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0;
                kluge->f.significand = 0;
                kluge->f.significand2 = 0;
                *ps = 0;
                return;

        case fp_infinity:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7fff;
                kluge->f.significand = 0x80000000;
                kluge->f.significand2 = 0;
                *ps = 0;
                return;

        case fp_quiet:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7fff;
                kluge->f.significand = 0xffffffff;
                kluge->f.significand2 = 0xffffffff;
                *ps = 0;
                return;

        case fp_signaling:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7fff;
                kluge->f.significand = 0xbfffffff;
                kluge->f.significand2 = 0xffffffff;
                *ps = 0;
                return;
        }

        /* numeric values */
        ef = 0;
        if (pd->exponent + pd->ndigits > EXTENDED_MAXE) {
                /* result must overflow */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = 0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else if (pd->exponent + pd->ndigits < -EXTENDED_MAXE) {
                /* result must underflow completely */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = -0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else {
                /* result may be in range */
                if (__fast_decimal_to_double(&dd.x, pm, pd, &ef) == 1 &&
                    ef == 0) {
                        u.sign = dd.f.msw.sign;
                        u.fpclass = fp_normal;
                        u.exponent = dd.f.msw.exponent - DOUBLE_BIAS;
                        u.significand[0] = ((0x100000 |
                            dd.f.msw.significand) << 11) |
                            (dd.f.significand2 >> 21);
                        u.significand[1] = dd.f.significand2 << 11;
                        for (i = 2; i < UNPACKED_SIZE; i++)
                                u.significand[i] = 0;
                } else {
                        __decimal_to_unpacked(&u, pd, 64);
                }
        }
        __pack_extended(&u, px, pm->rd, &ef);
        *ps = ef;
        if (ef != 0)
                __base_conversion_set_exception(ef);
}

void
decimal_to_quadruple(quadruple *px, decimal_mode *pm, decimal_record *pd,
    fp_exception_field_type *ps)
{
        quadruple_equivalence   *kluge;
        unpacked                u;
        double_equivalence      dd;
        fp_exception_field_type ef;
        int                     i;

        /* special values */
        kluge = (quadruple_equivalence *)px;
        switch (pd->fpclass) {
        case fp_zero:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0;
                kluge->f.msw.significand = 0;
                kluge->f.significand2 = 0;
                kluge->f.significand3 = 0;
                kluge->f.significand4 = 0;
                *ps = 0;
                return;

        case fp_infinity:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7fff;
                kluge->f.msw.significand = 0;
                kluge->f.significand2 = 0;
                kluge->f.significand3 = 0;
                kluge->f.significand4 = 0;
                *ps = 0;
                return;

        case fp_quiet:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7fff;
                kluge->f.msw.significand = 0xffff;
                kluge->f.significand2 = 0xffffffff;
                kluge->f.significand3 = 0xffffffff;
                kluge->f.significand4 = 0xffffffff;
                *ps = 0;
                return;

        case fp_signaling:
                kluge->f.msw.sign = (pd->sign)? 1 : 0;
                kluge->f.msw.exponent = 0x7fff;
                kluge->f.msw.significand = 0x7fff;
                kluge->f.significand2 = 0xffffffff;
                kluge->f.significand3 = 0xffffffff;
                kluge->f.significand4 = 0xffffffff;
                *ps = 0;
                return;
        }

        /* numeric values */
        ef = 0;
        if (pd->exponent + pd->ndigits > QUAD_MAXE) {
                /* result must overflow */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = 0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else if (pd->exponent + pd->ndigits < -QUAD_MAXE) {
                /* result must underflow completely */
                u.sign = (pd->sign != 0);
                u.fpclass = fp_normal;
                u.exponent = -0x000fffff;
                u.significand[0] = 0x80000000;
                for (i = 1; i < UNPACKED_SIZE; i++)
                        u.significand[i] = 0;
        } else {
                /* result may be in range */
                if (__fast_decimal_to_double(&dd.x, pm, pd, &ef) == 1 &&
                    ef == 0) {
                        u.sign = dd.f.msw.sign;
                        u.fpclass = fp_normal;
                        u.exponent = dd.f.msw.exponent - DOUBLE_BIAS;
                        u.significand[0] = ((0x100000 |
                            dd.f.msw.significand) << 11) |
                            (dd.f.significand2 >> 21);
                        u.significand[1] = dd.f.significand2 << 11;
                        for (i = 2; i < UNPACKED_SIZE; i++)
                                u.significand[i] = 0;
                } else {
                        __decimal_to_unpacked(&u, pd, 113);
                }
        }
        __pack_quadruple(&u, px, pm->rd, &ef);
        *ps = ef;
        if (ef != 0)
                __base_conversion_set_exception(ef);
}