strtold.c

// Copyright (C) 1985-1998 by Symantec
// Copyright (C) 2000-2011 by Digital Mars
// All Rights Reserved
// http://www.digitalmars.com
// Written by Walter Bright
/*
 * This source file is made available for personal use
 * only. The license is in /dmd/src/dmd/backendlicense.txt
 * or /dm/src/dmd/backendlicense.txt
 * For any other uses, please contact Digital Mars.
 */

#include        <stdio.h>
#include        <stdlib.h>
#include        <ctype.h>
#include        <float.h>
#include        <string.h>
#include        <math.h>
#if _WIN32 && __DMC__
#include        <fenv.h>
#include        <fltpnt.h>
#endif
#if linux || __APPLE__ || __FreeBSD__ || __OpenBSD__ || __sun&&__SVR4
#include        <errno.h>
#endif

#include        "longdouble.h"

#if _WIN32 && __DMC__
// from \sc\src\include\setlocal.h
extern char * __cdecl __locale_decpoint;
void __pascal __set_errno (int an_errno);
#endif

#if _WIN32 || linux || __APPLE__ || __FreeBSD__ || __OpenBSD__ || __sun&&__SVR4

#if 0
/* This is for compilers that don't support hex float literals,
 * and also makes it clearer what constants we're trying to use.
 */

static longdouble negtab[] =
        {1e-4096L,1e-2048L,1e-1024L,1e-512L,
         1e-256L,1e-128L,1e-64L,1e-32L,1e-16L,1e-8L,1e-4L,1e-2L,1e-1L,1.0L};

static longdouble postab[] =
        {1e+4096L,1e+2048L,1e+1024L,1e+512L,
         1e+256L,1e+128L,1e+64L,1e+32L,1e+16L,1e+8L,1e+4L,1e+2L,1e+1L};

#elif (defined(__GNUC__) && __FreeBSD__ && __i386__) || _MSC_VER

// GCC on FreeBSD/i386 incorrectly rounds long double constants to double precision.  Workaround:

// Note that the [sizeof(longdouble)] takes care of whatever the 0 padding is for the
// target platform

static unsigned char _negtab_bytes[][sizeof(longdouble)] =
        { { 0xDE,0x9F,0xCE,0xD2,0xC8,0x04,0xDD,0xA6,0xD8,0x0A,0xBF,0xBF },
          { 0xE4,0x2D,0x36,0x34,0x4F,0x53,0xAE,0xCE,0x6B,0x25,0xBF,0xBF },
          { 0xBE,0xC0,0x57,0xDA,0xA5,0x82,0xA6,0xA2,0xB5,0x32,0xBF,0xBF },
          { 0x1C,0xD2,0x23,0xDB,0x32,0xEE,0x49,0x90,0x5A,0x39,0xBF,0xBF },
          { 0x3A,0x19,0x7A,0x63,0x25,0x43,0x31,0xC0,0xAC,0x3C,0xBF,0xBF },
          { 0xA1,0xE4,0xBC,0x64,0x7C,0x46,0xD0,0xDD,0x55,0x3E,0xBF,0xBF },
          { 0xA5,0xE9,0x39,0xA5,0x27,0xEA,0x7F,0xA8,0x2A,0x3F,0xBF,0xBF },
          { 0xBA,0x94,0x39,0x45,0xAD,0x1E,0xB1,0xCF,0x94,0x3F,0xBF,0xBF },
          { 0x5B,0xE1,0x4D,0xC4,0xBE,0x94,0x95,0xE6,0xC9,0x3F,0xBF,0xBF },
          { 0xFD,0xCE,0x61,0x84,0x11,0x77,0xCC,0xAB,0xE4,0x3F,0xBF,0xBF },
          { 0x2C,0x65,0x19,0xE2,0x58,0x17,0xB7,0xD1,0xF1,0x3F,0xBF,0xBF },
          { 0x0A,0xD7,0xA3,0x70,0x3D,0x0A,0xD7,0xA3,0xF8,0x3F,0xBF,0xBF },
          { 0xCD,0xCC,0xCC,0xCC,0xCC,0xCC,0xCC,0xCC,0xFB,0x3F,0xBF,0xBF },
          { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0xFF,0x3F,0xBF,0xBF } };

static unsigned char _postab_bytes[][sizeof(longdouble)] =
        { { 0x9B,0x97,0x20,0x8A,0x02,0x52,0x60,0xC4,0x25,0x75,0x18,0x28 },
          { 0xE5,0x5D,0x3D,0xC5,0x5D,0x3B,0x8B,0x9E,0x92,0x5A,0x18,0x28 },
          { 0x17,0x0C,0x75,0x81,0x86,0x75,0x76,0xC9,0x48,0x4D,0x18,0x28 },
          { 0xC7,0x91,0x0E,0xA6,0xAE,0xA0,0x19,0xE3,0xA3,0x46,0x18,0x28 },
          { 0x8E,0xDE,0xF9,0x9D,0xFB,0xEB,0x7E,0xAA,0x51,0x43,0x18,0x28 },
          { 0xE0,0x8C,0xE9,0x80,0xC9,0x47,0xBA,0x93,0xA8,0x41,0x18,0x28 },
          { 0xD5,0xA6,0xCF,0xFF,0x49,0x1F,0x78,0xC2,0xD3,0x40,0x18,0x28 },
          { 0x9E,0xB5,0x70,0x2B,0xA8,0xAD,0xC5,0x9D,0x69,0x40,0x18,0x28 },
          { 0x00,0x00,0x00,0x04,0xBF,0xC9,0x1B,0x8E,0x34,0x40,0x18,0x28 },
          { 0x00,0x00,0x00,0x00,0x00,0x20,0xBC,0xBE,0x19,0x40,0x18,0x28 },
          { 0x00,0x00,0x00,0x00,0x00,0x00,0x40,0x9C,0x0C,0x40,0x18,0x28 },
          { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xC8,0x05,0x40,0x18,0x28 },
          { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xA0,0x02,0x40,0x18,0x28 },
          { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0xFF,0x3F,0x18,0x28 } };

static longdouble *negtab = (longdouble *) _negtab_bytes;
static longdouble *postab = (longdouble *) _postab_bytes;

#else

// Use exact values, computed separately, to bootstrap.
// The digits here past 17 are just for amusement value, they
// only contribute to the 'sticky' bit.

static longdouble negtab[] =
{
    1 / 0x62.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,
    1 / 0x9.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,
    1 / 0x3.25d9d61a05d4305d9434f4a3c62d433949ae6209d4926c3f5bd2db49ef47187094c1a6970ca7e6bd2a73c5534936a8de061e8d4649f4f3235e005b80411640114a88bc491b9fc4ed520190fba035faaba6c356e38a31b5653f445975836cb0b6c975a351a28e4262ce3ce3a0b8df68368ae26a7b7e976a3310fc8f1f9031eb0f669a20288280bda5a580d98089dc1a47fe6b7595fb101a3616b6f4654b31fb6bfdf56deeecb1b896bc8fc51a16bf3fdeb3d814b505ba34c4118ad822a51abe1de3045b7a748e1042c462be695a9f9f2a07a7e89431922bbb9fc96359861c5cd134f451218b65dc60d7233e55c7231d2b9c9fce837d1e43f61f7de16cfb896634ee0ed1440ecc2cd8194c7d1e1a140ac53515c51a88991c4e871ec29f866e7c215bf55b2b722919f001p+3400L,
    1 / 0x1c.633415d4c1d238d98cab8a978a0b1f138cb07303a269974845a71d46b099bc817343afac69be5b0e9449775c1366732a93abade4b2908ee0f95f635e85a91924c3fc0695e7fc7153329c57aebfa3edac96e14f5dbc51fb2eb21a2f221e25cfea703ed321aa1da1bf28f8733b4475b579c88976c194e6574746c40513c31e1ad9b83a8a975d96976f8f9546dc77f27267fc6cf801p+1696L,
    1 / 0x5.53f75fdcefcef46eeddc80dcc7f755bc28f265f9ef17cc5573c063ff540e3c42d35a1d153624adc666b026b2716ed595d80fcf4a6e706bde50c612152f87d8d99f72bed3875b982e7c01p+848L,
    1 / 0x2.4ee91f2603a6337f19bccdb0dac404dc08d3cff5ec2374e42f0f1538fd03df99092e953e01p+424L,
    1 / 0x18.4f03e93ff9f4daa797ed6e38ed64bf6a1f01p+208L,
    1 / 0x4.ee2d6d415b85acef81p+104L,
    1 / 0x23.86f26fc1p+48L,
    1 / 0x5.f5e1p+24L,
    1 / 0x27.10p+8L,
    1 / 0x64.p+0L,
    1 / 0xa.p+0L,
};

static longdouble postab[] =
{
    0x62.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,
    0x9.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,
    0x3.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,
    0x1c.633415d4c1d238d98cab8a978a0b1f138cb07303a269974845a71d46b099bc817343afac69be5b0e9449775c1366732a93abade4b2908ee0f95f635e85a91924c3fc0695e7fc7153329c57aebfa3edac96e14f5dbc51fb2eb21a2f221e25cfea703ed321aa1da1bf28f8733b4475b579c88976c194e6574746c40513c31e1ad9b83a8a975d96976f8f9546dc77f27267fc6cf801p+1696L,
    0x5.53f75fdcefcef46eeddc80dcc7f755bc28f265f9ef17cc5573c063ff540e3c42d35a1d153624adc666b026b2716ed595d80fcf4a6e706bde50c612152f87d8d99f72bed3875b982e7c01p+848L,
    0x2.4ee91f2603a6337f19bccdb0dac404dc08d3cff5ec2374e42f0f1538fd03df99092e953e01p+424L,
    0x18.4f03e93ff9f4daa797ed6e38ed64bf6a1f01p+208L,
    0x4.ee2d6d415b85acef81p+104L,
    0x23.86f26fc1p+48L,
    0x5.f5e1p+24L,
    0x27.10p+8L,
    0x64.p+0L,
    0xa.p+0L,
};

#endif

/*************************
 * Convert string to double.
 * Terminates on first unrecognized character.
 */

longdouble strtold(const char *p,char **endp)
{
        longdouble ldval;
        int exp;
        long long msdec,lsdec;
        unsigned long msscale;
        char dot,sign;
        int pow;
        int ndigits;
        const char *pinit = p;
        static char infinity[] = "infinity";
        static char nans[] = "nans";
        unsigned int old_cw;
        unsigned int old_status;

#if _WIN32 && __DMC__
        fenv_t flagp;
        fegetenv(&flagp);  /* Store all exceptions, and current status word */
        if (_8087)
        {
            // disable exceptions from occurring, set max precision, and round to nearest
#if __DMC__
            __asm
            {
                fstcw   word ptr old_cw
                mov     EAX,old_cw
                mov     ECX,EAX
                and     EAX,0xf0c0
                or      EAX,033fh
                mov     old_cw,EAX
                fldcw   word ptr old_cw
                mov     old_cw,ECX
            }
#else
            old_cw = _control87(_MCW_EM | _PC_64  | _RC_NEAR,
                                _MCW_EM | _MCW_PC | _MCW_RC);
#endif
        }
#endif

        while (isspace(*p))
            p++;
        sign = 0;                       /* indicating +                 */
        switch (*p)
        {       case '-':
                        sign++;
                        /* FALL-THROUGH */
                case '+':
                        p++;
        }
        ldval = 0.0;
        dot = 0;                        /* if decimal point has been seen */
        exp = 0;
        msdec = lsdec = 0;
        msscale = 1;
        ndigits = 0;

#if __DMC__
        switch (*p)
        {   case 'i':
            case 'I':
                if (memicmp(p,infinity,8) == 0)
                {   p += 8;
                    goto L4;
                }
                if (memicmp(p,infinity,3) == 0)         /* is it "inf"? */
                {   p += 3;
                L4:
                    ldval = HUGE_VAL;
                    goto L3;
                }
                break;
            case 'n':
            case 'N':
                if (memicmp(p,nans,4) == 0)             /* "nans"?      */
                {   p += 4;
                    ldval = NANS;
                    goto L5;
                }
                if (memicmp(p,nans,3) == 0)             /* "nan"?       */
                {   p += 3;
                    ldval = NAN;
                L5:
                    if (*p == '(')              /* if (n-char-sequence) */
                        goto Lerr;              /* invalid input        */
                    goto L3;
                }
        }
#endif

        if (*p == '0' && (p[1] == 'x' || p[1] == 'X'))
        {   int guard = 0;
            int anydigits = 0;

            p += 2;
            while (1)
            {   int i = *p;

                while (isxdigit(i))
                {
                    anydigits = 1;
                    i = isalpha(i) ? ((i & ~0x20) - ('A' - 10)) : i - '0';
                    if (ndigits < 16)
                    {
                        msdec = msdec * 16 + i;
                        if (msdec)
                            ndigits++;
                    }
                    else if (ndigits == 16)
                    {
                        while (msdec >= 0)
                        {
                            exp--;
                            msdec <<= 1;
                            i <<= 1;
                            if (i & 0x10)
                                msdec |= 1;
                        }
                        guard = i << 4;
                        ndigits++;
                        exp += 4;
                    }
                    else
                    {
                        guard |= i;
                        exp += 4;
                    }
                    exp -= dot;
                    i = *++p;
                }
#if _WIN32 && __DMC__
                if (i == *__locale_decpoint && !dot)
#else
                if (i == '.' && !dot)
#endif
                {       p++;
                        dot = 4;
                }
                else
                        break;
            }

            // Round up if (guard && (sticky || odd))
            if (guard & 0x80 && (guard & 0x7F || msdec & 1))
            {
                msdec++;
                if (msdec == 0)                 // overflow
                {   msdec = 0x8000000000000000LL;
                    exp++;
                }
            }

            if (anydigits == 0)         // if error (no digits seen)
                goto Lerr;
            if (*p == 'p' || *p == 'P')
            {
                char sexp;
                int e;

                sexp = 0;
                switch (*++p)
                {   case '-':    sexp++;
                    case '+':    p++;
                }
                ndigits = 0;
                e = 0;
                while (isdigit(*p))
                {
                    if (e < 0x7FFFFFFF / 10 - 10) // prevent integer overflow
                    {
                        e = e * 10 + *p - '0';
                    }
                    p++;
                    ndigits = 1;
                }
                exp += (sexp) ? -e : e;
                if (!ndigits)           // if no digits in exponent
                    goto Lerr;

                if (msdec)
                {
#if __DMC__
                    // The 8087 has no instruction to load an
                    // unsigned long long
                    if (msdec < 0)
                    {
                        *(long long *)&ldval = msdec;
                        ((unsigned short *)&ldval)[4] = 0x3FFF + 63;
                    }
                    else
                    {   // But does for a signed one
                        __asm
                        {
                            fild        qword ptr msdec
                            fstp        tbyte ptr ldval
                        }
                    }
#else
                    int e2 = 0x3FFF + 63;

                    // left justify mantissa
                    while (msdec >= 0)
                    {   msdec <<= 1;
                        e2--;
                    }

                    // Stuff mantissa directly into long double
                    *(long long *)&ldval = msdec;
                    ((unsigned short *)&ldval)[4] = e2;
#endif

#if 0
                    if (0)
                    {   int i;
                        printf("msdec = x%llx, ldval = %Lg\n", msdec, ldval);
                        for (i = 0; i < 5; i++)
                            printf("%04x ",((unsigned short *)&ldval)[i]);
                        printf("\n");
                        printf("%llx\n",ldval);
                    }
#endif
                    // Exponent is power of 2, not power of 10
#if _WIN32 && __DMC__
                    __asm
                    {
                        fild    dword ptr exp
                        fld     tbyte ptr ldval
                        fscale                  // ST(0) = ST(0) * (2**ST(1))
                        fstp    ST(1)
                        fstp    tbyte ptr ldval
                    }
#else
                    ldval = ldexpl(ldval,exp);
#endif
                }
                goto L6;
            }
            else
                goto Lerr;              // exponent is required
        }
        else
        {
            while (1)
            {   int i = *p;

                while (isdigit(i))
                {
                    ndigits = 1;        /* must have at least 1 digit   */
                    if (msdec < (0x7FFFFFFFFFFFLL-10)/10)
                        msdec = msdec * 10 + (i - '0');
                    else if (msscale < (0xFFFFFFFF-10)/10)
                    {   lsdec = lsdec * 10 + (i - '0');
                        msscale *= 10;
                    }
                    else
                    {
                        exp++;
                    }
                    exp -= dot;
                    i = *++p;
                }
#if _WIN32 && __DMC__
                if (i == *__locale_decpoint && !dot)
#else
                if (i == '.' && !dot)
#endif
                {       p++;
                        dot++;
                }
                else
                        break;
            }
            if (!ndigits)               // if error (no digits seen)
                goto Lerr;              // return 0.0
        }
        if (*p == 'e' || *p == 'E')
        {
            char sexp;
            int e;

            sexp = 0;
            switch (*++p)
            {   case '-':    sexp++;
                case '+':    p++;
            }
            ndigits = 0;
            e = 0;
            while (isdigit(*p))
            {
                if (e < 0x7FFFFFFF / 10 - 10)   // prevent integer overflow
                {
                    e = e * 10 + *p - '0';
                }
                p++;
                ndigits = 1;
            }
            exp += (sexp) ? -e : e;
            if (!ndigits)               // if no digits in exponent
                goto Lerr;              // return 0.0
        }

#if _WIN32 && __DMC__
        __asm
        {
            fild        qword ptr msdec
            mov         EAX,msscale
            cmp         EAX,1
            je          La1
            fild        long ptr msscale
            fmul
            fild        qword ptr lsdec
            fadd
        La1:
            fstp        tbyte ptr ldval
        }
#else
        ldval = msdec;
        if (msscale != 1)               /* if stuff was accumulated in lsdec */
            ldval = ldval * msscale + lsdec;
#endif
        if (ldval)
        {   unsigned u;

            u = 0;
            pow = 4096;

#if _WIN32 && __DMC__
            //printf("msdec = x%x, lsdec = x%x, msscale = x%x\n",msdec,lsdec,msscale);
            //printf("dval = %g, x%llx, exp = %d\n",dval,dval,exp);
            __asm fld   tbyte ptr ldval
#endif

            while (exp > 0)
            {
                while (exp >= pow)
                {
#if _WIN32 && __DMC__
                        __asm
                        {
                            mov         EAX,u
                            imul        EAX,10
                            fld         tbyte ptr postab[EAX]
                            fmul
                        }
#else
                        ldval *= postab[u];
#endif
                        exp -= pow;
                }
                pow >>= 1;
                u++;
            }
#if _WIN32 && __DMC__
            __asm fstp  tbyte ptr ldval
#endif
            while (exp < 0)
            {   while (exp <= -pow)
                {
#if _WIN32 && __DMC__
                        __asm
                        {
                            mov         EAX,u
                            imul        EAX,10
                            fld         tbyte ptr ldval
                            fld         tbyte ptr negtab[EAX]
                            fmul
                            fstp        tbyte ptr ldval
                        }
#else
                        ldval *= negtab[u];
#endif
                        if (ldval == 0)
#if _WIN32 && __DMC__
                                __set_errno (ERANGE);
#else
                                errno = ERANGE;
#endif
                        exp += pow;
                }
                pow >>= 1;
                u++;
            }
#if 0
            if (0)
            {   int i;
                for (i = 0; i < 5; i++)
                    printf("%04x ",ldval.value[i]);
                printf("\n");
                printf("%llx\n",dval);
            }
#endif
        }
    L6: // if overflow occurred
        if (ldval == HUGE_VAL)
#if _WIN32 && __DMC__
            __set_errno (ERANGE);               // range error
#else
            errno = ERANGE;
#endif

    L1:
        if (endp)
        {
            *endp = (char *) p;
        }
    L3:
#if _WIN32 && __DMC__
        fesetenv(&flagp);               // reset floating point environment
        if (_8087)
        {
            __asm
            {
                xor     EAX,EAX
                fstsw   AX
                fclex
                fldcw   word ptr old_cw
            }
        }
#endif

        return (sign) ? -ldval : ldval;

    Lerr:
        p = pinit;
        goto L1;
}

#else

longdouble strtold(const char *p,char **endp)
{
    return strtod(p, endp);
}

#endif

/************************* Test ************************************/

#if 0

#include <stdio.h>
#include <float.h>
#include <errno.h>

extern "C" longdouble strtold(const char *p,char **endp);

struct longdouble
{
        unsigned short value[5];
};

void main()
{
    longdouble ld;
    struct longdouble x;
    int i;

    errno = 0;
//  ld = strtold("0x1.FFFFFFFFFFFFFFFEp16383", NULL);
    ld = strtold("0x1.FFFFFFFFFFFFFFFEp-16382", NULL);
    x = *(struct longdouble *)&ld;
    for (i = 4; i >= 0; i--)
    {
        printf("%04x ", x.value[i]);
    }
    printf("\t%d\n", errno);

    ld = strtold("1.0e5", NULL);
    x = *(struct longdouble *)&ld;
    for (i = 4; i >= 0; i--)
    {
        printf("%04x ", x.value[i]);
    }
    printf("\n");
}

#endif

/************************* Bigint ************************************/

#if 0

/* This program computes powers of 10 exactly.
 * Used to generate postab[].
 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define NDIGITS 4096

void times10(unsigned *a)
{
    int i;

    for (i = 0; i < NDIGITS; i++)
    {
        a[i] *= 10;
        if (i)
        {
            a[i] += a[i - 1] >> 8;
            a[i - 1] &= 0xFF;
        }
    }
}

void print(unsigned *a)
{
    int i;
    int p;
    int j;

    for (i = NDIGITS; i; )
    {
        --i;
        if (a[i])
            break;
    }

    printf("0x%x.", a[i]);
    p = i * 8;
    i--;
    for (j = 0; j < i; j++)
        if (a[j])
            break;
    for (; i >= j; i--)
    {
        printf("%02x", a[i]);
    }
    printf("p+%d", p);
}

void main()
{
    unsigned a[NDIGITS];
    int i;
    int j;

    static longdouble tab[] =
    {
        0x62.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,
        0x9.e8b3b5dc53d5de4a74d28ce329ace526a3197bbebe3034f77154ce2bcba19648b21c11eb962b1b61b93cf2ee5ca6f7e928e61d08e2d694222771e50f30278c9836230af908b40a753b7d77cd8c6be7151aab4efac5dcd83e49d6907855eeb028af623f6f7024d2c36fa9ce9d04a487fa1fb992be221ef1bd0ad5f775677ce0de08402ad3fa140eac7d56c7c9dee0bedd8a6c038f9245b2e87c348ad803ecca8f0070f8dbb57a6a445f278b3d5cf42915e818415c7f3ef82df84658ccf45cfad379433f3389a4408f43c513ef5a83fb8886fbf56d9d4bd5f860792e55ecee70beb1810d76ce39de9ec24bcf99d01953761abd9d7389c0a244de3c195355d84eeebeee6f46eadb56c6815b785ce6b7b125ac8edb0708fd8f6cae5f5715f7915b33eb417bf03c19d7917c7ba1fc6b9681428c85744695f0e866d7efc9ac375d77c1a42f40660460944545ff87a7dc62d752f7a66a57b1ab730f203c1aa9f44484d80e2e5fc5a04779c56b8a9e110c7bcbea4ca7982da4663cfe491d0dbd21feab49869733554c36685e5510c4a656654419bd438e48ff35d6c7d6ab91bac974fb1264b4f111821fa2bca416afe609c313b41e449952fbed5a151440967abbb3a8281ed6a8f16f9210c17f94e3892ee98074ff01e3cb64f32dbb6643a7a8289c8c6c54de34c101349713b44938209ce1f3861ce0fb7fedcc235552eb57a7842d71c7fd8f66912e4ad2f869c29279498719342c12866ed6f1c850dabc98342c9e51b78db2ea50d142fd8277732ed56d55a5e5a191368b8abbb6067584ee87e354ec2e472149e28dcfb27d4d3fe30968651333e001p+6800L,
        0x3.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,
        0x1c.633415d4c1d238d98cab8a978a0b1f138cb07303a269974845a71d46b099bc817343afac69be5b0e9449775c1366732a93abade4b2908ee0f95f635e85a91924c3fc0695e7fc7153329c57aebfa3edac96e14f5dbc51fb2eb21a2f221e25cfea703ed321aa1da1bf28f8733b4475b579c88976c194e6574746c40513c31e1ad9b83a8a975d96976f8f9546dc77f27267fc6cf801p+1696L,
        0x5.53f75fdcefcef46eeddc80dcc7f755bc28f265f9ef17cc5573c063ff540e3c42d35a1d153624adc666b026b2716ed595d80fcf4a6e706bde50c612152f87d8d99f72bed3875b982e7c01p+848L,
        0x2.4ee91f2603a6337f19bccdb0dac404dc08d3cff5ec2374e42f0f1538fd03df99092e953e01p+424L,
        0x18.4f03e93ff9f4daa797ed6e38ed64bf6a1f01p+208L,
        0x4.ee2d6d415b85acef81p+104L,
        0x23.86f26fc1p+48L,
        0x5.f5e1p+24L,
        0x27.10p+8L,
        0x64.p+0L,
        0xa.p+0L,
    };

    for (j = 1; j <= 4096; j *= 2)
    {
        printf("%4d: ", j);
        memset(a, 0, sizeof(a));
        a[0] = 1;
        for (i = 0; i < j; i++)
            times10(a);
        print(a);
        printf("L,\n");
    }

    for (i = 0; i < 13; i++)
    {
        printf("tab[%d] = %Lg\n", i, tab[i]);
    }
}

#endif