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libc/newlib/libc/stdlib/strtod.c

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/*
FUNCTION
<<strtod>>, <<strtof>>, <<strtold>>, <<strtod_l>>, <<strtof_l>>, <<strtold_l>>---string to double or float
INDEX
strtod
INDEX
strtof
INDEX
strtold
INDEX
strtod_l
INDEX
strtof_l
INDEX
strtold_l
INDEX
_strtod_r
SYNOPSIS
#include <stdlib.h>
double strtod(const char *restrict <[str]>, char **restrict <[tail]>);
float strtof(const char *restrict <[str]>, char **restrict <[tail]>);
long double strtold(const char *restrict <[str]>,
char **restrict <[tail]>);
#include <stdlib.h>
double strtod_l(const char *restrict <[str]>, char **restrict <[tail]>,
locale_t <[locale]>);
float strtof_l(const char *restrict <[str]>, char **restrict <[tail]>,
locale_t <[locale]>);
long double strtold_l(const char *restrict <[str]>,
char **restrict <[tail]>,
locale_t <[locale]>);
double _strtod_r(void *<[reent]>,
const char *restrict <[str]>, char **restrict <[tail]>);
DESCRIPTION
<<strtod>>, <<strtof>>, <<strtold>> parse the character string
<[str]>, producing a substring which can be converted to a double,
float, or long double value, respectively. 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]>.
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.
<<strtod_l>>, <<strtof_l>>, <<strtold_l>> are like <<strtod>>,
<<strtof>>, <<strtold>> but perform the conversion based on the
locale specified by the locale object locale. If <[locale]> is
LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is
undefined.
The alternate function <<_strtod_r>> is a reentrant version.
The extra argument <[reent]> is a pointer to a reentrancy structure.
RETURNS
These functions return 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>> (<<HUGE_VALF>>, <<HUGE_VALL>>) is returned, and
<<ERANGE>> is stored in errno. If the correct value would cause
underflow, 0 is returned and <<ERANGE>> is stored in errno.
PORTABILITY
<<strtod>> is ANSI.
<<strtof>>, <<strtold>> are C99.
<<strtod_l>>, <<strtof_l>>, <<strtold_l>> are GNU extensions.
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. */
#define _GNU_SOURCE
#include <_ansi.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "mprec.h"
#include "gdtoa.h"
#include "../locale/setlocale.h"
/* #ifndef NO_FENV_H */
/* #include <fenv.h> */
/* #endif */
#include "locale.h"
#ifdef IEEE_Arith
#ifndef NO_IEEE_Scale
#define Avoid_Underflow
#undef tinytens
/* The factor of 2^106 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,
#ifdef _DOUBLE_IS_32BITS
0.0, 0.0, 0.0
#else
1e-64, 1e-128,
9007199254740992. * 9007199254740992.e-256
#endif
};
#endif
#endif
#ifdef Honor_FLT_ROUNDS
#define Rounding rounding
#undef Check_FLT_ROUNDS
#define Check_FLT_ROUNDS
#else
#define Rounding Flt_Rounds
#endif
#ifdef IEEE_MC68k
#define _0 0
#define _1 1
#else
#define _0 1
#define _1 0
#endif
#ifdef Avoid_Underflow /*{*/
static double
sulp (U x,
int scale)
{
U u;
double rv;
int i;
rv = ulp(dval(x));
if (!scale || (i = 2*P + 1 - ((dword0(x) & Exp_mask) >> Exp_shift)) <= 0)
return rv; /* Is there an example where i <= 0 ? */
dword0(u) = Exp_1 + ((__int32_t)i << Exp_shift);
#ifndef _DOUBLE_IS_32BITS
dword1(u) = 0;
#endif
return rv * u.d;
}
#endif /*}*/
#ifndef NO_HEX_FP
static void
ULtod (__ULong *L,
__ULong *bits,
Long exp,
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 */
double
_strtod_l (struct _reent *ptr, const char *__restrict s00, char **__restrict se,
locale_t loc)
{
#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 = NULL, *bb1, *bd = NULL, *bd0, *bs = NULL, *delta = NULL;
#ifdef Avoid_Underflow
__ULong Lsb, Lsb1;
#endif
#ifdef SET_INEXACT
int inexact, oldinexact;
#endif
#ifdef Honor_FLT_ROUNDS
int rounding;
#endif
const char *decimal_point = __get_numeric_locale(loc)->decimal_point;
int dec_len = strlen (decimal_point);
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 const 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
0 is still valid. */
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, loc)) & STRTOG_Retmask) {
case STRTOG_NoNumber:
s = s00;
sign = 0;
/* FALLTHROUGH */
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
z = 10*z + c - '0';
nd0 = nd;
if (strncmp (s, decimal_point, dec_len) == 0)
{
decpt = 1;
c = *(s += dec_len);
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 const 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
dval(rv) = nan ("");
#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;
#else
dword0(rv) = Tiny1;
#endif /*_DOUBLE_IS_32BITS*/
/* The refinement below will clean
* this approximation up.
*/
}
#endif
}
}
/* Now the hard part -- adjusting rv to the correct value.*/
/* Put digits into bd: true value = bd * 10^e */
bd0 = s2b(ptr, s0, nd0, nd, y);
if (bd0 == NULL)
goto ovfl;
for(;;) {
bd = Balloc(ptr,bd0->_k);
if (bd == NULL)
goto ovfl;
Bcopy(bd, bd0);
bb = d2b(ptr,dval(rv), &bbe, &bbbits); /* rv = bb * 2^bbe */
if (bb == NULL)
goto ovfl;
bs = i2b(ptr,1);
if (bs == NULL)
goto ovfl;
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;
#ifdef Honor_FLT_ROUNDS
if (rounding != 1)
bs2++;
#endif
#ifdef Avoid_Underflow
Lsb = LSB;
Lsb1 = 0;
j = bbe - scale;
i = j + bbbits - 1; /* logb(rv) */
j = P + 1 - bbbits;
if (i < Emin) { /* denormal */
i = Emin - i;
j -= i;
if (i < 32)
Lsb <<= i;
else
Lsb1 = Lsb << (i-32);
}
#else /*Avoid_Underflow*/
#ifdef Sudden_Underflow
#ifdef IBM
j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3);
#else
j = P + 1 - bbbits;
#endif
#else /*Sudden_Underflow*/
j = bbe;
i = j + bbbits - 1; /* logb(rv) */
if (i < Emin) /* denormal */
j += P - Emin;
else
j = P + 1 - bbbits;
#endif /*Sudden_Underflow*/
#endif /*Avoid_Underflow*/
bb2 += j;
bd2 += j;
#ifdef Avoid_Underflow
bd2 += scale;
#endif
i = bb2 < bd2 ? bb2 : bd2;
if (i > bs2)
i = bs2;
if (i > 0) {
bb2 -= i;
bd2 -= i;
bs2 -= i;
}
if (bb5 > 0) {
bs = pow5mult(ptr, bs, bb5);
if (bs == NULL)
goto ovfl;
bb1 = mult(ptr, bs, bb);
if (bb1 == NULL)
goto ovfl;
Bfree(ptr, bb);
bb = bb1;
}
if (bb2 > 0) {
bb = lshift(ptr, bb, bb2);
if (bb == NULL)
goto ovfl;
}
if (bd5 > 0) {
bd = pow5mult(ptr, bd, bd5);
if (bd == NULL)
goto ovfl;
}
if (bd2 > 0) {
bd = lshift(ptr, bd, bd2);
if (bd == NULL)
goto ovfl;
}
if (bs2 > 0) {
bs = lshift(ptr, bs, bs2);
if (bs == NULL)
goto ovfl;
}
delta = diff(ptr, bb, bd);
if (delta == NULL)
goto ovfl;
dsign = delta->_sign;
delta->_sign = 0;
i = cmp(delta, bs);
#ifdef Honor_FLT_ROUNDS
if (rounding != 1) {
if (i < 0) {
/* Error is less than an ulp */
if (!delta->_x[0] && delta->_wds <= 1) {
/* exact */
#ifdef SET_INEXACT
inexact = 0;
#endif
break;
}
if (rounding) {
if (dsign) {
adj = 1.;
goto apply_adj;
}
}
else if (!dsign) {
adj = -1.;
if (!dword1(rv)
&& !(dword0(rv) & Frac_mask)) {
y = dword0(rv) & Exp_mask;
#ifdef Avoid_Underflow
if (!scale || y > 2*P*Exp_msk1)
#else
if (y)
#endif
{
delta = lshift(ptr, delta,Log2P);
if (cmp(delta, bs) <= 0)
adj = -0.5;
}
}
apply_adj:
#ifdef Avoid_Underflow
if (scale && (y = dword0(rv) & Exp_mask)
<= 2*P*Exp_msk1)
dword0(adj) += (2*P+1)*Exp_msk1 - y;
#else
#ifdef Sudden_Underflow
if ((dword0(rv) & Exp_mask) <=
P*Exp_msk1) {
dword0(rv) += P*Exp_msk1;
dval(rv) += adj*ulp(dval(rv));
dword0(rv) -= P*Exp_msk1;
}
else
#endif /*Sudden_Underflow*/
#endif /*Avoid_Underflow*/
dval(rv) += adj*ulp(dval(rv));
}
break;
}
adj = ratio(delta, bs);
if (adj < 1.)
adj = 1.;
if (adj <= 0x7ffffffe) {
/* adj = rounding ? ceil(adj) : floor(adj); */
y = adj;
if (y != adj) {
if (!((rounding>>1) ^ dsign))
y++;
adj = y;
}
}
#ifdef Avoid_Underflow
if (scale && (y = dword0(rv) & Exp_mask) <= 2*P*Exp_msk1)
dword0(adj) += (2*P+1)*Exp_msk1 - y;
#else
#ifdef Sudden_Underflow
if ((dword0(rv) & Exp_mask) <= P*Exp_msk1) {
dword0(rv) += P*Exp_msk1;
adj *= ulp(dval(rv));
if (dsign)
dval(rv) += adj;
else
dval(rv) -= adj;
dword0(rv) -= P*Exp_msk1;
goto cont;
}
#endif /*Sudden_Underflow*/
#endif /*Avoid_Underflow*/
adj *= ulp(dval(rv));
if (dsign) {
if (dword0(rv) == Big0 && dword1(rv) == Big1)
goto ovfl;
dval(rv) += adj;
else
dval(rv) -= adj;
goto cont;
}
#endif /*Honor_FLT_ROUNDS*/
if (i < 0) {
/* Error is less than half an ulp -- check for
* special case of mantissa a power of two.
*/
if (dsign || dword1(rv) || dword0(rv) & Bndry_mask
#ifdef IEEE_Arith
#ifdef Avoid_Underflow
|| (dword0(rv) & Exp_mask) <= (2*P+1)*Exp_msk1
#else
|| (dword0(rv) & Exp_mask) <= Exp_msk1
#endif
#endif
) {
#ifdef SET_INEXACT
if (!delta->x[0] && delta->wds <= 1)
inexact = 0;
#endif
break;
}
if (!delta->_x[0] && delta->_wds <= 1) {
/* exact result */
#ifdef SET_INEXACT
inexact = 0;
#endif
break;
}
delta = lshift(ptr,delta,Log2P);
if (cmp(delta, bs) > 0)
goto drop_down;
break;
}
if (i == 0) {
/* exactly half-way between */
if (dsign) {
if ((dword0(rv) & Bndry_mask1) == Bndry_mask1
&& dword1(rv) == (
#ifdef Avoid_Underflow
(scale && (y = dword0(rv) & Exp_mask) <= 2*P*Exp_msk1)
? (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) :
#endif
0xffffffff)) {
/*boundary case -- increment exponent*/
if (dword0(rv) == Big0 && dword1(rv) == Big1)
goto ovfl;
dword0(rv) = (dword0(rv) & Exp_mask)
+ Exp_msk1
#ifdef IBM
| Exp_msk1 >> 4
#endif
;
#ifndef _DOUBLE_IS_32BITS
dword1(rv) = 0;
#endif /*!_DOUBLE_IS_32BITS*/
#ifdef Avoid_Underflow
dsign = 0;
#endif
break;
}
}
else if (!(dword0(rv) & Bndry_mask) && !dword1(rv)) {
drop_down:
/* boundary case -- decrement exponent */
#ifdef Sudden_Underflow /*{{*/
L = dword0(rv) & Exp_mask;
#ifdef IBM
if (L < Exp_msk1)
#else
#ifdef Avoid_Underflow
if (L <= (scale ? (2*P+1)*Exp_msk1 : Exp_msk1))
#else
if (L <= Exp_msk1)
#endif /*Avoid_Underflow*/
#endif /*IBM*/
goto undfl;
L -= Exp_msk1;
#else /*Sudden_Underflow}{*/
#ifdef Avoid_Underflow
if (scale) {
L = dword0(rv) & Exp_mask;
if (L <= (2*P+1)*Exp_msk1) {
if (L > (P+2)*Exp_msk1)
/* round even ==> */
/* accept rv */
break;
/* rv = smallest denormal */
goto undfl;
}
}
#endif /*Avoid_Underflow*/
L = (dword0(rv) & Exp_mask) - Exp_msk1;
#endif /*Sudden_Underflow}*/
dword0(rv) = L | Bndry_mask1;
#ifndef _DOUBLE_IS_32BITS
dword1(rv) = 0xffffffff;
#endif /*!_DOUBLE_IS_32BITS*/
#ifdef IBM
goto cont;
#else
break;
#endif
}
#ifndef ROUND_BIASED
#ifdef Avoid_Underflow
if (Lsb1) {
if (!(dword0(rv) & Lsb1))
break;
}
else if (!(dword1(rv) & Lsb))
break;
#else
if (!(dword1(rv) & LSB))
break;
#endif
#endif
if (dsign)
#ifdef Avoid_Underflow
dval(rv) += sulp(rv, scale);
#else
dval(rv) += ulp(dval(rv));
#endif
#ifndef ROUND_BIASED
else {
#ifdef Avoid_Underflow
dval(rv) -= sulp(rv, scale);
#else
dval(rv) -= ulp(dval(rv));
#endif
#ifndef Sudden_Underflow
if (!dval(rv))
goto undfl;
#endif
}
#ifdef Avoid_Underflow
dsign = 1 - dsign;
#endif
#endif
break;
}
if ((aadj = ratio(delta, bs)) <= 2.) {
if (dsign)
aadj = dval(aadj1) = 1.;
else if (dword1(rv) || dword0(rv) & Bndry_mask) {
#ifndef Sudden_Underflow
if (dword1(rv) == Tiny1 && !dword0(rv))
goto undfl;
#endif
aadj = 1.;
dval(aadj1) = -1.;
}
else {
/* special case -- power of FLT_RADIX to be */
/* rounded down... */
if (aadj < 2./FLT_RADIX)
aadj = 1./FLT_RADIX;
else
aadj *= 0.5;
dval(aadj1) = -aadj;
}
}
else {
aadj *= 0.5;
dval(aadj1) = dsign ? aadj : -aadj;
#ifdef Check_FLT_ROUNDS
switch(Rounding) {
case 2: /* towards +infinity */
dval(aadj1) -= 0.5;
break;
case 0: /* towards 0 */
case 3: /* towards -infinity */
dval(aadj1) += 0.5;
}
#else
if (Flt_Rounds == 0)
dval(aadj1) += 0.5;
#endif /*Check_FLT_ROUNDS*/
}
y = dword0(rv) & Exp_mask;
/* Check for overflow */
if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
dval(rv0) = dval(rv);
dword0(rv) -= P*Exp_msk1;
adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
if ((dword0(rv) & Exp_mask) >=
Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
if (dword0(rv0) == Big0 && dword1(rv0) == Big1)
goto ovfl;
dword0(rv) = Big0;
#ifndef _DOUBLE_IS_32BITS
dword1(rv) = Big1;
#endif /*!_DOUBLE_IS_32BITS*/
goto cont;
}
else
dword0(rv) += P*Exp_msk1;
}
else {
#ifdef Avoid_Underflow
if (scale && y <= 2*P*Exp_msk1) {
if (aadj <= 0x7fffffff) {
if ((z = aadj) == 0)
z = 1;
aadj = z;
dval(aadj1) = dsign ? aadj : -aadj;
}
dword0(aadj1) += (2*P+1)*Exp_msk1 - y;
}
adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
#else
#ifdef Sudden_Underflow
if ((dword0(rv) & Exp_mask) <= P*Exp_msk1) {
dval(rv0) = dval(rv);
dword0(rv) += P*Exp_msk1;
adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
#ifdef IBM
if ((dword0(rv) & Exp_mask) < P*Exp_msk1)
#else
if ((dword0(rv) & Exp_mask) <= P*Exp_msk1)
#endif
{
if (dword0(rv0) == Tiny0
&& dword1(rv0) == Tiny1)
goto undfl;
#ifndef _DOUBLE_IS_32BITS
dword0(rv) = Tiny0;
dword1(rv) = Tiny1;
#else
dword0(rv) = Tiny1;
#endif /*_DOUBLE_IS_32BITS*/
goto cont;
}
else
dword0(rv) -= P*Exp_msk1;
}
else {
adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
}
#else /*Sudden_Underflow*/
/* Compute adj so that the IEEE rounding rules will
* correctly round rv + adj in some half-way cases.
* If rv * ulp(rv) is denormalized (i.e.,
* y <= (P-1)*Exp_msk1), we must adjust aadj to avoid
* trouble from bits lost to denormalization;
* example: 1.2e-307 .
*/
if (y <= (P-1)*Exp_msk1 && aadj > 1.) {
dval(aadj1) = (double)(int)(aadj + 0.5);
if (!dsign)
dval(aadj1) = -dval(aadj1);
}
adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
#endif /*Sudden_Underflow*/
#endif /*Avoid_Underflow*/
}
z = dword0(rv) & Exp_mask;
#ifndef SET_INEXACT
#ifdef Avoid_Underflow
if (!scale)
#endif
if (y == z) {
/* Can we stop now? */
#ifndef _DOUBLE_IS_32BITS
/* If FE_INVALID floating point exceptions are
enabled, a conversion to a 32 bit value is
dangerous. A positive double value can result
in a negative 32 bit int, thus raising SIGFPE.
To avoid this, always convert into 64 bit here. */
__int64_t L = (__int64_t)aadj;
#else
L = (Long)aadj;
#endif
aadj -= L;
/* The tolerances below are conservative. */
if (dsign || dword1(rv) || dword0(rv) & Bndry_mask) {
if (aadj < .4999999 || aadj > .5000001)
break;
}
else if (aadj < .4999999/FLT_RADIX)
break;
}
#endif
cont:
Bfree(ptr,bb);
Bfree(ptr,bd);
Bfree(ptr,bs);
Bfree(ptr,delta);
}
#ifdef SET_INEXACT
if (inexact) {
if (!oldinexact) {
dword0(rv0) = Exp_1 + (70 << Exp_shift);
#ifndef _DOUBLE_IS_32BITS
dword1(rv0) = 0;
#endif /*!_DOUBLE_IS_32BITS*/
dval(rv0) += 1.;
}
}
else if (!oldinexact)
clear_inexact();
#endif
#ifdef Avoid_Underflow
if (scale) {
dword0(rv0) = Exp_1 - 2*P*Exp_msk1;
#ifndef _DOUBLE_IS_32BITS
dword1(rv0) = 0;
#endif /*!_DOUBLE_IS_32BITS*/
dval(rv) *= dval(rv0);
#ifndef NO_ERRNO
/* try to avoid the bug of testing an 8087 register value */
if (dword0(rv) == 0 && dword1(rv) == 0)
ptr->_errno = ERANGE;
#endif
}
#endif /* Avoid_Underflow */
#ifdef SET_INEXACT
if (inexact && !(dword0(rv) & Exp_mask)) {
/* set underflow bit */
dval(rv0) = 1e-300;
dval(rv0) *= dval(rv0);
}
#endif
retfree:
Bfree(ptr,bb);
Bfree(ptr,bd);
Bfree(ptr,bs);
Bfree(ptr,bd0);
Bfree(ptr,delta);
ret:
if (se)
*se = (char *)s;
return sign ? -dval(rv) : dval(rv);
}
double
_strtod_r (struct _reent *ptr,
const char *__restrict s00,
char **__restrict se)
{
return _strtod_l (ptr, s00, se, __get_current_locale ());
}
#ifndef _REENT_ONLY
double
strtod_l (const char *__restrict s00, char **__restrict se, locale_t loc)
{
return _strtod_l (_REENT, s00, se, loc);
}
double
strtod (const char *__restrict s00, char **__restrict se)
{
return _strtod_l (_REENT, s00, se, __get_current_locale ());
}
float
strtof_l (const char *__restrict s00, char **__restrict se, locale_t loc)
{
double val = _strtod_l (_REENT, s00, se, loc);
if (isnan (val))
return signbit (val) ? -nanf ("") : nanf ("");
float retval = (float) val;
#ifndef NO_ERRNO
if (isinf (retval) && !isinf (val))
_REENT->_errno = ERANGE;
#endif
return retval;
}
float
strtof (const char *__restrict s00,
char **__restrict se)
{
double val = _strtod_l (_REENT, s00, se, __get_current_locale ());
if (isnan (val))
return signbit (val) ? -nanf ("") : nanf ("");
float retval = (float) val;
#ifndef NO_ERRNO
if (isinf (retval) && !isinf (val))
_REENT->_errno = ERANGE;
#endif
return retval;
}
#endif
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