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/*

FUNCTION

        <<strtod>>, <<strtof>>---string to double or float

INDEX

        strtod

INDEX

        _strtod_r

INDEX

        strtof

ANSI_SYNOPSIS

        #include <stdlib.h>

        double strtod(const char *<[str]>, char **<[tail]>);

        float strtof(const char *<[str]>, char **<[tail]>);

        double _strtod_r(void *<[reent]>,

                         const char *<[str]>, char **<[tail]>);

TRAD_SYNOPSIS

        #include <stdlib.h>

        double strtod(<[str]>,<[tail]>)

        char *<[str]>;

        char **<[tail]>;

        float strtof(<[str]>,<[tail]>)

        char *<[str]>;

        char **<[tail]>;

        double _strtod_r(<[reent]>,<[str]>,<[tail]>)

        char *<[reent]>;

        char *<[str]>;

        char **<[tail]>;

DESCRIPTION

        The function <<strtod>> parses the character string <[str]>,

        producing a substring which can be converted to a double

        value.  The substring converted is the longest initial

        subsequence of <[str]>, beginning with the first

        non-whitespace character, that has one of these formats:

        .[+|-]<[digits]>[.[<[digits]>]][(e|E)[+|-]<[digits]>]

        .[+|-].<[digits]>[(e|E)[+|-]<[digits]>]

        .[+|-](i|I)(n|N)(f|F)[(i|I)(n|N)(i|I)(t|T)(y|Y)]

        .[+|-](n|N)(a|A)(n|N)[<(>[<[hexdigits]>]<)>]

        .[+|-]0(x|X)<[hexdigits]>[.[<[hexdigits]>]][(p|P)[+|-]<[digits]>]

        .[+|-]0(x|X).<[hexdigits]>[(p|P)[+|-]<[digits]>]

        The substring contains no characters if <[str]> is empty, consists

        entirely of whitespace, or if the first non-whitespace

        character is something other than <<+>>, <<->>, <<.>>, or a

        digit, and cannot be parsed as infinity or NaN. If the platform

        does not support NaN, then NaN is treated as an empty substring.

        If the substring is empty, no conversion is done, and

        the value of <[str]> is stored in <<*<[tail]>>>.  Otherwise,

        the substring is converted, and a pointer to the final string

        (which will contain at least the terminating null character of

        <[str]>) is stored in <<*<[tail]>>>.  If you want no

        assignment to <<*<[tail]>>>, pass a null pointer as <[tail]>.

        <<strtof>> is identical to <<strtod>> except for its return type.

        This implementation returns the nearest machine number to the

        input decimal string.  Ties are broken by using the IEEE

        round-even rule.  However, <<strtof>> is currently subject to

        double rounding errors.

        The alternate function <<_strtod_r>> is a reentrant version.

        The extra argument <[reent]> is a pointer to a reentrancy structure.

RETURNS

        <<strtod>> returns the converted substring value, if any.  If

        no conversion could be performed, 0 is returned.  If the

        correct value is out of the range of representable values,

        plus or minus <<HUGE_VAL>> is returned, and <<ERANGE>> is

        stored in errno. If the correct value would cause underflow, 0

        is returned and <<ERANGE>> is stored in errno.

Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,

<<lseek>>, <<read>>, <<sbrk>>, <<write>>.

*/

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

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 ".").      */

/* Original file gdtoa-strtod.c Modified 06-21-2006 by Jeff Johnston to work within newlib.  */

#include <_ansi.h>

#include <errno.h>

#include <stdlib.h>

#include <string.h>

#include "mprec.h"

#include "gdtoa.h"

#include "gd_qnan.h"

/* #ifndef NO_FENV_H */

/* #include <fenv.h> */

/* #endif */

#ifdef USE_LOCALE

#include "locale.h"

#endif

#ifdef IEEE_Arith

#ifndef NO_IEEE_Scale

#define Avoid_Underflow

#undef tinytens

/* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */

/* flag unnecessarily.  It leads to a song and dance at the end of strtod. */

static _CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128,

                9007199254740992.e-256

                };

#endif

#endif

#ifdef Honor_FLT_ROUNDS

#define Rounding rounding

#undef Check_FLT_ROUNDS

#define Check_FLT_ROUNDS

#else

#define Rounding Flt_Rounds

#endif

#ifndef NO_HEX_FP

static void

_DEFUN (ULtod, (L, bits, exp, k),

        __ULong *L _AND

        __ULong *bits _AND

        Long exp _AND

        int k)

{

        switch(k & STRTOG_Retmask) {

          case STRTOG_NoNumber:

          case STRTOG_Zero:

                L[0] = L[1] = 0;

                break;

          case STRTOG_Denormal:

                L[_1] = bits[0];

                L[_0] = bits[1];

                break;

          case STRTOG_Normal:

          case STRTOG_NaNbits:

                L[_1] = bits[0];

                L[_0] = (bits[1] & ~0x100000) | ((exp + 0x3ff + 52) << 20);

                break;

          case STRTOG_Infinite:

                L[_0] = 0x7ff00000;

                L[_1] = 0;

                break;

          case STRTOG_NaN:

                L[_0] = 0x7fffffff;

                L[_1] = (__ULong)-1;

          }

        if (k & STRTOG_Neg)

                L[_0] |= 0x80000000L;

}

#endif /* !NO_HEX_FP */

#ifdef INFNAN_CHECK

static int

_DEFUN (match, (sp, t),

        _CONST char **sp _AND

        char *t)

{

        int c, d;

        _CONST char *s = *sp;

        while( (d = *t++) !=0) {

                if ((c = *++s) >= 'A' && c <= 'Z')

                        c += 'a' - 'A';

                if (c != d)

                        return 0;

                }

        *sp = s + 1;

        return 1;

}

#endif /* INFNAN_CHECK */

double

_DEFUN (_strtod_r, (ptr, s00, se),

        struct _reent *ptr _AND

        _CONST char *s00 _AND

        char **se)

{

#ifdef Avoid_Underflow

        int scale;

#endif

        int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, dsign,

                 e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign;

        _CONST char *s, *s0, *s1;

        double aadj, adj;

        U aadj1, rv, rv0;

        Long L;

        __ULong y, z;

        _Bigint *bb, *bb1, *bd, *bd0, *bs, *delta;

#ifdef SET_INEXACT

        int inexact, oldinexact;

#endif

#ifdef Honor_FLT_ROUNDS

        int rounding;

#endif

        delta = bs = bd = NULL;

        sign = nz0 = nz = decpt = 0;

        dval(rv) = 0.;

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

                case '-':

                        sign = 1;

                        /* no break */

                case '+':

                        if (*++s)

                                goto break2;

                        /* no break */

                case 0:

                        goto ret0;

                case '\t':

                case '\n':

                case '\v':

                case '\f':

                case '\r':

                case ' ':

                        continue;

                default:

                        goto break2;

                }

 break2:

        if (*s == '0') {

#ifndef NO_HEX_FP

                {

                static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, SI };

                Long exp;

                __ULong bits[2];

                switch(s[1]) {

                  case 'x':

                  case 'X':

                        /* If the number is not hex, then the parse of

                        s00 = s + 1;

                        {

#if defined(FE_DOWNWARD) && defined(FE_TONEAREST) && defined(FE_TOWARDZERO) && defined(FE_UPWARD)

                        FPI fpi1 = fpi;

                        switch(fegetround()) {

                          case FE_TOWARDZERO:   fpi1.rounding = 0; break;

                          case FE_UPWARD:       fpi1.rounding = 2; break;

                          case FE_DOWNWARD:     fpi1.rounding = 3;

                          }

#else

#define fpi1 fpi

#endif

                        switch((i = gethex(ptr, &s, &fpi1, &exp, &bb, sign)) & STRTOG_Retmask) {

                          case STRTOG_NoNumber:

                                s = s00;

                          case STRTOG_Zero:

                                break;

                          default:

                                if (bb) {

                                        copybits(bits, fpi.nbits, bb);

                                        Bfree(ptr,bb);

                                        }

                                ULtod(rv.i, bits, exp, i);

                          }}

                        goto ret;

                  }

                }

#endif

                nz0 = 1;

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

                if (!*s)

                        goto ret;

                }

        s0 = s;

        y = z = 0;

        for(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 (c == *localeconv()->decimal_point)

#else

        if (c == '.')

#endif

                {

                decpt = 1;

                c = *++s;

                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) {

                        goto ret0;

                        }

                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 */

                        __ULong bits[2];

                        static FPI fpinan =     /* only 52 explicit bits */

                                { 52, 1-1023-53+1, 2046-1023-53+1, 1, SI };

                        if (!decpt)

                         switch(c) {

                          case 'i':

                          case 'I':

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

                                        --s;

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

                                                ++s;

                                        dword0(rv) = 0x7ff00000;

#ifndef _DOUBLE_IS_32BITS

                                        dword1(rv) = 0;

#endif /*!_DOUBLE_IS_32BITS*/

                                        goto ret;

                                        }

                                break;

                          case 'n':

                          case 'N':

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

#ifndef No_Hex_NaN

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

                                         && hexnan(&s, &fpinan, bits)

                                                        == STRTOG_NaNbits) {

                                                dword0(rv) = 0x7ff00000 | bits[1];

#ifndef _DOUBLE_IS_32BITS

                                                dword1(rv) = bits[0];

#endif /*!_DOUBLE_IS_32BITS*/

                                                }

                                        else {

#endif

                                                dword0(rv) = NAN_WORD0;

#ifndef _DOUBLE_IS_32BITS

                                                dword1(rv) = NAN_WORD1;

#endif /*!_DOUBLE_IS_32BITS*/

#ifndef No_Hex_NaN

                                                }

#endif

                                        goto ret;

                                        }

                          }

#endif /* INFNAN_CHECK */

 ret0:

                        s = s00;

                        sign = 0;

                        }

                goto ret;

                }

        e1 = e -= nf;

        /* 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) {

#ifdef SET_INEXACT

                if (k > DBL_DIG)

                        oldinexact = get_inexact();

#endif

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

                }

        bd0 = 0;

        if (nd <= DBL_DIG

#ifndef RND_PRODQUOT

#ifndef Honor_FLT_ROUNDS

                && Flt_Rounds == 1

#endif

#endif

                        ) {

                if (!e)

                        goto ret;

                if (e > 0) {

                        if (e <= Ten_pmax) {

#ifdef VAX

                                goto vax_ovfl_check;

#else

#ifdef Honor_FLT_ROUNDS

                                /* round correctly FLT_ROUNDS = 2 or 3 */

                                if (sign) {

                                        dval(rv) = -dval(rv);

                                        sign = 0;

                                        }

#endif

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

                                goto ret;

#endif

                                }

                        i = DBL_DIG - nd;

                        if (e <= Ten_pmax + i) {

                                /* A fancier test would sometimes let us do

                                 * this for larger i values.

                                 */

#ifdef Honor_FLT_ROUNDS

                                /* round correctly FLT_ROUNDS = 2 or 3 */

                                if (sign) {

                                        dval(rv) = -dval(rv);

                                        sign = 0;

                                        }

#endif

                                e -= i;

                                dval(rv) *= tens[i];

#ifdef VAX

                                /* VAX exponent range is so narrow we must

                                 * worry about overflow here...

                                 */

 vax_ovfl_check:

                                dword0(rv) -= P*Exp_msk1;

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

                                if ((dword0(rv) & Exp_mask)

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

                                        goto ovfl;

                                dword0(rv) += P*Exp_msk1;

#else

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

#endif

                                goto ret;

                                }

                        }

#ifndef Inaccurate_Divide

                else if (e >= -Ten_pmax) {

#ifdef Honor_FLT_ROUNDS

                        /* round correctly FLT_ROUNDS = 2 or 3 */

                        if (sign) {

                                dval(rv) = -dval(rv);

                                sign = 0;

                                }

#endif

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

                        goto ret;

                        }

#endif

                }

        e1 += nd - k;

#ifdef IEEE_Arith

#ifdef SET_INEXACT

        inexact = 1;

        if (k <= DBL_DIG)

                oldinexact = get_inexact();

#endif

#ifdef Avoid_Underflow

        scale = 0;

#endif

#ifdef Honor_FLT_ROUNDS

        if ((rounding = Flt_Rounds) >= 2) {

                if (sign)

                        rounding = rounding == 2 ? 0 : 2;

                else

                        if (rounding != 2)

                                rounding = 0;

                }

#endif

#endif /*IEEE_Arith*/

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

        if (e1 > 0) {

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

                        dval(rv) *= tens[i];

                if (e1 &= ~15) {

                        if (e1 > DBL_MAX_10_EXP) {

 ovfl:

#ifndef NO_ERRNO

                                ptr->_errno = ERANGE;

#endif

                                /* Can't trust HUGE_VAL */

#ifdef IEEE_Arith

#ifdef Honor_FLT_ROUNDS

                                switch(rounding) {

                                  case 0: /* toward 0 */

                                  case 3: /* toward -infinity */

                                        dword0(rv) = Big0;

#ifndef _DOUBLE_IS_32BITS

                                        dword1(rv) = Big1;

#endif /*!_DOUBLE_IS_32BITS*/

                                        break;

                                  default:

                                        dword0(rv) = Exp_mask;

#ifndef _DOUBLE_IS_32BITS

                                        dword1(rv) = 0;

#endif /*!_DOUBLE_IS_32BITS*/

                                  }

#else /*Honor_FLT_ROUNDS*/

                                dword0(rv) = Exp_mask;

#ifndef _DOUBLE_IS_32BITS

                                dword1(rv) = 0;

#endif /*!_DOUBLE_IS_32BITS*/

#endif /*Honor_FLT_ROUNDS*/

#ifdef SET_INEXACT

                                /* set overflow bit */

                                dval(rv0) = 1e300;

                                dval(rv0) *= dval(rv0);

#endif

#else /*IEEE_Arith*/

                                dword0(rv) = Big0;

#ifndef _DOUBLE_IS_32BITS

                                dword1(rv) = Big1;

#endif /*!_DOUBLE_IS_32BITS*/

#endif /*IEEE_Arith*/

                                if (bd0)

                                        goto retfree;

                                goto ret;

                                }

                        e1 >>= 4;

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

                                if (e1 & 1)

                                        dval(rv) *= bigtens[j];

                /* The last multiplication could overflow. */

                        dword0(rv) -= P*Exp_msk1;

                        dval(rv) *= bigtens[j];

                        if ((z = dword0(rv) & Exp_mask)

                         > Exp_msk1*(DBL_MAX_EXP+Bias-P))

                                goto ovfl;

                        if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) {

                                /* set to largest number */

                                /* (Can't trust DBL_MAX) */

                                dword0(rv) = Big0;

#ifndef _DOUBLE_IS_32BITS

                                dword1(rv) = Big1;

#endif /*!_DOUBLE_IS_32BITS*/

                                }

                        else

                                dword0(rv) += P*Exp_msk1;

                        }

                }

        else if (e1 < 0) {

                e1 = -e1;

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

                        dval(rv) /= tens[i];

                if (e1 >>= 4) {

                        if (e1 >= 1 << n_bigtens)

                                goto undfl;

#ifdef Avoid_Underflow

                        if (e1 & Scale_Bit)

                                scale = 2*P;

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

                                if (e1 & 1)

                                        dval(rv) *= tinytens[j];

                        if (scale && (j = 2*P + 1 - ((dword0(rv) & Exp_mask)

                                                >> Exp_shift)) > 0) {

                                /* scaled rv is denormal; zap j low bits */

                                if (j >= 32) {

#ifndef _DOUBLE_IS_32BITS

                                        dword1(rv) = 0;

#endif /*!_DOUBLE_IS_32BITS*/

                                        if (j >= 53)

                                         dword0(rv) = (P+2)*Exp_msk1;

                                        else

                                         dword0(rv) &= 0xffffffff << (j-32);

                                        }

#ifndef _DOUBLE_IS_32BITS

                                else

                                        dword1(rv) &= 0xffffffff << j;

#endif /*!_DOUBLE_IS_32BITS*/

                                }

#else

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

                                if (e1 & 1)

                                        dval(rv) *= tinytens[j];

                        /* The last multiplication could underflow. */

                        dval(rv0) = dval(rv);

                        dval(rv) *= tinytens[j];

                        if (!dval(rv)) {

                                dval(rv) = 2.*dval(rv0);

                                dval(rv) *= tinytens[j];

#endif

                                if (!dval(rv)) {

 undfl:

                                        dval(rv) = 0.;

#ifndef NO_ERRNO

                                        ptr->_errno = ERANGE;

#endif

                                        if (bd0)

                                                goto retfree;

                                        goto ret;

                                        }

#ifndef Avoid_Underflow

#ifndef _DOUBLE_IS_32BITS

                                dword0(rv) = Tiny0;

                                dword1(rv) = Tiny1;