Intravision/reactos
1
0
Fork 0
mirror of https://github.com/reactos/reactos.git synced 2025-07-03 14:31:22 +00:00
Code Issues Projects Releases Packages Wiki Activity
reactos/sdk/lib/3rdparty/stlport/src/num_get_float.cpp

884 lines
25 KiB
C++
Raw Normal View History

[STLPORT] Copy stlport from cmake branch 1/x svn path=/trunk/; revision=51778
2011-05-16 12:54:24 +00:00
/*
* Copyright (c) 1999
* Silicon Graphics Computer Systems, Inc.
*
* Copyright (c) 1999
* Boris Fomitchev
*
* This material is provided "as is", with absolutely no warranty expressed
* or implied. Any use is at your own risk.
*
* Permission to use or copy this software for any purpose is hereby granted
* without fee, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
*/
#include "stlport_prefix.h"
#include <limits>
#include <locale>
#include <istream>
#if (defined (__GNUC__) && !defined (__sun) && !defined (__hpux)) || \
defined (__DMC__)
# include <stdint.h>
#endif
#if defined (__linux__) || defined (__MINGW32__) || defined (__CYGWIN__) || \
defined (__BORLANDC__) || defined (__DMC__) || defined (__HP_aCC)
# if defined (__BORLANDC__)
typedef unsigned int uint32_t;
typedef unsigned __int64 uint64_t;
# endif
union _ll {
uint64_t i64;
struct {
# if defined (_STLP_BIG_ENDIAN)
uint32_t hi;
uint32_t lo;
# elif defined (_STLP_LITTLE_ENDIAN)
uint32_t lo;
uint32_t hi;
# else
# error Unknown endianess
# endif
} i32;
};
# if defined (__linux__)
# include <ieee754.h>
# else
union ieee854_long_double {
long double d;
/* This is the IEEE 854 double-extended-precision format. */
struct {
unsigned int mantissa1:32;
unsigned int mantissa0:32;
unsigned int exponent:15;
unsigned int negative:1;
unsigned int empty:16;
} ieee;
};
# define IEEE854_LONG_DOUBLE_BIAS 0x3fff
# endif
#endif
_STLP_BEGIN_NAMESPACE
_STLP_MOVE_TO_PRIV_NAMESPACE
//----------------------------------------------------------------------
// num_get
// Helper functions for _M_do_get_float.
#if !defined (_STLP_NO_WCHAR_T)
void _STLP_CALL
_Initialize_get_float( const ctype<wchar_t>& ct,
wchar_t& Plus, wchar_t& Minus,
wchar_t& pow_e, wchar_t& pow_E,
wchar_t* digits) {
char ndigits[11] = "0123456789";
Plus = ct.widen('+');
Minus = ct.widen('-');
pow_e = ct.widen('e');
pow_E = ct.widen('E');
ct.widen(ndigits + 0, ndigits + 10, digits);
}
#endif /* WCHAR_T */
/*
* __string_to_double is just lifted from atof, the difference being
* that we just use '.' for the decimal point, rather than let it
* be taken from the current C locale, which of course is not accessible
* to us.
*/
#if defined (_STLP_MSVC) || defined (__BORLANDC__) || defined (__ICL)
typedef unsigned long uint32;
typedef unsigned __int64 uint64;
# define ULL(x) x##Ui64
#elif defined (__unix) || defined (__MINGW32__) || \
(defined (__DMC__) && (__LONGLONG)) || defined (__WATCOMC__)
typedef uint32_t uint32;
typedef uint64_t uint64;
# define ULL(x) x##ULL
#else
# error There should be some unsigned 64-bit integer on the system!
#endif
// Multiplication of two 64-bit integers, giving a 128-bit result.
// Taken from Algorithm M in Knuth section 4.3.1, with the loop
// hand-unrolled.
static void _Stl_mult64(const uint64 u, const uint64 v,
uint64& high, uint64& low) {
const uint64 low_mask = ULL(0xffffffff);
const uint64 u0 = u & low_mask;
const uint64 u1 = u >> 32;
const uint64 v0 = v & low_mask;
const uint64 v1 = v >> 32;
uint64 t = u0 * v0;
low = t & low_mask;
t = u1 * v0 + (t >> 32);
uint64 w1 = t & low_mask;
uint64 w2 = t >> 32;
uint64 x = u0 * v1 + w1;
low += (x & low_mask) << 32;
high = u1 * v1 + w2 + (x >> 32);
}
#ifndef __linux__
# define bit11 ULL(0x7ff)
# define exponent_mask (bit11 << 52)
# if !defined (__GNUC__) || (__GNUC__ != 3) || (__GNUC_MINOR__ != 4) || \
(!defined (__CYGWIN__) && !defined (__MINGW32__))
//Generate bad code when compiled with -O2 option.
inline
# endif
void _Stl_set_exponent(uint64 &val, uint64 exp)
{ val = (val & ~exponent_mask) | ((exp & bit11) << 52); }
#endif // __linux__
/* Power of ten fractions for tenscale*/
/* The constants are factored so that at most two constants
* and two multiplies are needed. Furthermore, one of the constants
* is represented exactly - 10**n where 1<= n <= 27.
*/
static const uint64 _Stl_tenpow[80] = {
ULL(0xa000000000000000), /* _Stl_tenpow[0]=(10**1)/(2**4) */
ULL(0xc800000000000000), /* _Stl_tenpow[1]=(10**2)/(2**7) */
ULL(0xfa00000000000000), /* _Stl_tenpow[2]=(10**3)/(2**10) */
ULL(0x9c40000000000000), /* _Stl_tenpow[3]=(10**4)/(2**14) */
ULL(0xc350000000000000), /* _Stl_tenpow[4]=(10**5)/(2**17) */
ULL(0xf424000000000000), /* _Stl_tenpow[5]=(10**6)/(2**20) */
ULL(0x9896800000000000), /* _Stl_tenpow[6]=(10**7)/(2**24) */
ULL(0xbebc200000000000), /* _Stl_tenpow[7]=(10**8)/(2**27) */
ULL(0xee6b280000000000), /* _Stl_tenpow[8]=(10**9)/(2**30) */
ULL(0x9502f90000000000), /* _Stl_tenpow[9]=(10**10)/(2**34) */
ULL(0xba43b74000000000), /* _Stl_tenpow[10]=(10**11)/(2**37) */
ULL(0xe8d4a51000000000), /* _Stl_tenpow[11]=(10**12)/(2**40) */
ULL(0x9184e72a00000000), /* _Stl_tenpow[12]=(10**13)/(2**44) */
ULL(0xb5e620f480000000), /* _Stl_tenpow[13]=(10**14)/(2**47) */
ULL(0xe35fa931a0000000), /* _Stl_tenpow[14]=(10**15)/(2**50) */
ULL(0x8e1bc9bf04000000), /* _Stl_tenpow[15]=(10**16)/(2**54) */
ULL(0xb1a2bc2ec5000000), /* _Stl_tenpow[16]=(10**17)/(2**57) */
ULL(0xde0b6b3a76400000), /* _Stl_tenpow[17]=(10**18)/(2**60) */
ULL(0x8ac7230489e80000), /* _Stl_tenpow[18]=(10**19)/(2**64) */
ULL(0xad78ebc5ac620000), /* _Stl_tenpow[19]=(10**20)/(2**67) */
ULL(0xd8d726b7177a8000), /* _Stl_tenpow[20]=(10**21)/(2**70) */
ULL(0x878678326eac9000), /* _Stl_tenpow[21]=(10**22)/(2**74) */
ULL(0xa968163f0a57b400), /* _Stl_tenpow[22]=(10**23)/(2**77) */
ULL(0xd3c21bcecceda100), /* _Stl_tenpow[23]=(10**24)/(2**80) */
ULL(0x84595161401484a0), /* _Stl_tenpow[24]=(10**25)/(2**84) */
ULL(0xa56fa5b99019a5c8), /* _Stl_tenpow[25]=(10**26)/(2**87) */
ULL(0xcecb8f27f4200f3a), /* _Stl_tenpow[26]=(10**27)/(2**90) */
ULL(0xd0cf4b50cfe20766), /* _Stl_tenpow[27]=(10**55)/(2**183) */
ULL(0xd2d80db02aabd62c), /* _Stl_tenpow[28]=(10**83)/(2**276) */
ULL(0xd4e5e2cdc1d1ea96), /* _Stl_tenpow[29]=(10**111)/(2**369) */
ULL(0xd6f8d7509292d603), /* _Stl_tenpow[30]=(10**139)/(2**462) */
ULL(0xd910f7ff28069da4), /* _Stl_tenpow[31]=(10**167)/(2**555) */
ULL(0xdb2e51bfe9d0696a), /* _Stl_tenpow[32]=(10**195)/(2**648) */
ULL(0xdd50f1996b947519), /* _Stl_tenpow[33]=(10**223)/(2**741) */
ULL(0xdf78e4b2bd342cf7), /* _Stl_tenpow[34]=(10**251)/(2**834) */
ULL(0xe1a63853bbd26451), /* _Stl_tenpow[35]=(10**279)/(2**927) */
ULL(0xe3d8f9e563a198e5), /* _Stl_tenpow[36]=(10**307)/(2**1020) */
// /* _Stl_tenpow[36]=(10**335)/(2**) */
// /* _Stl_tenpow[36]=(10**335)/(2**) */
ULL(0xfd87b5f28300ca0e), /* _Stl_tenpow[37]=(10**-28)/(2**-93) */
ULL(0xfb158592be068d2f), /* _Stl_tenpow[38]=(10**-56)/(2**-186) */
ULL(0xf8a95fcf88747d94), /* _Stl_tenpow[39]=(10**-84)/(2**-279) */
ULL(0xf64335bcf065d37d), /* _Stl_tenpow[40]=(10**-112)/(2**-372) */
ULL(0xf3e2f893dec3f126), /* _Stl_tenpow[41]=(10**-140)/(2**-465) */
ULL(0xf18899b1bc3f8ca2), /* _Stl_tenpow[42]=(10**-168)/(2**-558) */
ULL(0xef340a98172aace5), /* _Stl_tenpow[43]=(10**-196)/(2**-651) */
ULL(0xece53cec4a314ebe), /* _Stl_tenpow[44]=(10**-224)/(2**-744) */
ULL(0xea9c227723ee8bcb), /* _Stl_tenpow[45]=(10**-252)/(2**-837) */
ULL(0xe858ad248f5c22ca), /* _Stl_tenpow[46]=(10**-280)/(2**-930) */
ULL(0xe61acf033d1a45df), /* _Stl_tenpow[47]=(10**-308)/(2**-1023) */
ULL(0xe3e27a444d8d98b8), /* _Stl_tenpow[48]=(10**-336)/(2**-1116) */
ULL(0xe1afa13afbd14d6e) /* _Stl_tenpow[49]=(10**-364)/(2**-1209) */
};
static const short _Stl_twoexp[80] = {
4,7,10,14,17,20,24,27,30,34,37,40,44,47,50,54,57,60,64,67,70,74,77,80,84,87,90,
183,276,369,462,555,648,741,834,927,1020,
-93,-186,-279,-372,-465,-558,-651,-744,-837,-930,-1023,-1116,-1209
};
#define TEN_1 0 /* offset to 10 ** 1 */
#define TEN_27 26 /* offset to 10 ** 27 */
#define TEN_M28 37 /* offset to 10 ** -28 */
#define NUM_HI_P 11
#define NUM_HI_N 13
#define _Stl_HIBITULL (ULL(1) << 63)
static void _Stl_norm_and_round(uint64& p, int& norm, uint64 prodhi, uint64 prodlo) {
norm = 0;
if ((prodhi & _Stl_HIBITULL) == 0) {
/* leading bit is a zero
* may have to normalize
*/
if ((prodhi == ~_Stl_HIBITULL) &&
((prodlo >> 62) == 0x3)) { /* normalization followed by round
* would cause carry to create
* extra bit, so don't normalize
*/
p = _Stl_HIBITULL;
return;
}
p = (prodhi << 1) | (prodlo >> 63); /* normalize */
norm = 1;
prodlo <<= 1;
}
else {
p = prodhi;
}
if ((prodlo & _Stl_HIBITULL) != 0) { /* first guard bit a one */
if (((p & 0x1) != 0) ||
prodlo != _Stl_HIBITULL ) { /* not borderline for round to even */
/* round */
++p;
if (p == 0)
++p;
}
}
}
// Convert a 64-bitb fraction * 10^exp to a 64-bit fraction * 2^bexp.
// p: 64-bit fraction
// exp: base-10 exponent
// bexp: base-2 exponent (output parameter)
static void _Stl_tenscale(uint64& p, int exp, int& bexp) {
bexp = 0;
if ( exp == 0 ) { /* no scaling needed */
return;
}
int exp_hi = 0, exp_lo = exp; /* exp = exp_hi*32 + exp_lo */
int tlo = TEN_1, thi; /* offsets in power of ten table */
int num_hi; /* number of high exponent powers */
if (exp > 0) { /* split exponent */
if (exp_lo > 27) {
exp_lo++;
while (exp_lo > 27) {
exp_hi++;
exp_lo -= 28;
}
}
thi = TEN_27;
num_hi = NUM_HI_P;
} else { // exp < 0
while (exp_lo < 0) {
exp_hi++;
exp_lo += 28;
}
thi = TEN_M28;
num_hi = NUM_HI_N;
}
uint64 prodhi, prodlo; /* 128b product */
int norm; /* number of bits of normalization */
int hi, lo; /* offsets in power of ten table */
while (exp_hi) { /* scale */
hi = (min) (exp_hi, num_hi); /* only a few large powers of 10 */
exp_hi -= hi; /* could iterate in extreme case */
hi += thi-1;
_Stl_mult64(p, _Stl_tenpow[hi], prodhi, prodlo);
_Stl_norm_and_round(p, norm, prodhi, prodlo);
bexp += _Stl_twoexp[hi] - norm;
}
if (exp_lo) {
lo = tlo + exp_lo -1;
_Stl_mult64(p, _Stl_tenpow[lo], prodhi, prodlo);
_Stl_norm_and_round(p, norm, prodhi, prodlo);
bexp += _Stl_twoexp[lo] - norm;
}
return;
}
// First argument is a buffer of values from 0 to 9, NOT ascii.
// Second argument is number of digits in buffer, 1 <= digits <= 17.
// Third argument is base-10 exponent.
/* IEEE representation */
#if !defined (__linux__)
union _Double_rep {
uint64 ival;
double val;
};
static double _Stl_atod(char *buffer, ptrdiff_t ndigit, int dexp) {
typedef numeric_limits<double> limits;
_Double_rep drep;
uint64 &value = drep.ival; /* Value develops as follows:
* 1) decimal digits as an integer
* 2) left adjusted fraction
* 3) right adjusted fraction
* 4) exponent and fraction
*/
uint32 guard; /* First guard bit */
uint64 rest; /* Remaining guard bits */
int bexp; /* binary exponent */
int nzero; /* number of non-zero bits */
int sexp; /* scaling exponent */
char *bufferend; /* pointer to char after last digit */
/* Convert the decimal digits to a binary integer. */
bufferend = buffer + ndigit;
value = 0;
while (buffer < bufferend) {
value *= 10;
value += *buffer++;
}
/* Check for zero and treat it as a special case */
if (value == 0) {
return 0.0;
}
/* Normalize value */
bexp = 64; /* convert from 64b int to fraction */
/* Count number of non-zeroes in value */
nzero = 0;
if ((value >> 32) != 0) { nzero = 32; } //*TY 03/25/2000 - added explicit comparison to zero to avoid uint64 to bool conversion operator
if ((value >> (16 + nzero)) != 0) { nzero += 16; }
if ((value >> ( 8 + nzero)) != 0) { nzero += 8; }
if ((value >> ( 4 + nzero)) != 0) { nzero += 4; }
if ((value >> ( 2 + nzero)) != 0) { nzero += 2; }
if ((value >> ( 1 + nzero)) != 0) { nzero += 1; }
if ((value >> ( nzero)) != 0) { nzero += 1; }
/* Normalize */
value <<= /*(uint64)*/ (64 - nzero); //*TY 03/25/2000 - removed extraneous cast to uint64
bexp -= 64 - nzero;
/* At this point we have a 64b fraction and a binary exponent
* but have yet to incorporate the decimal exponent.
*/
/* multiply by 10^dexp */
_Stl_tenscale(value, dexp, sexp);
bexp += sexp;
if (bexp <= -1022) { /* HI denorm or underflow */
bexp += 1022;
if (bexp < -53) { /* guaranteed underflow */
value = 0;
}
else { /* denorm or possible underflow */
int lead0 = 12 - bexp; /* 12 sign and exponent bits */
/* we must special case right shifts of more than 63 */
if (lead0 > 64) {
rest = value;
guard = 0;
value = 0;
}
else if (lead0 == 64) {
rest = value & ((ULL(1)<< 63)-1);
guard = (uint32) ((value>> 63) & 1 );
value = 0;
}
else {
rest = value & (((ULL(1) << lead0)-1)-1);
guard = (uint32) (((value>> lead0)-1) & 1);
value >>= /*(uint64)*/ lead0; /* exponent is zero */
}
/* Round */
if (guard && ((value & 1) || rest) ) {
++value;
if (value == (ULL(1) << (limits::digits - 1))) { /* carry created normal number */
value = 0;
_Stl_set_exponent(value, 1);
}
}
}
}
else { /* not zero or denorm */
/* Round to 53 bits */
rest = value & ((1 << 10) - 1);
value >>= 10;
guard = (uint32) value & 1;
value >>= 1;
/* value&1 guard rest Action
*
* dc 0 dc none
* 1 1 dc round
* 0 1 0 none
* 0 1 !=0 round
*/
if (guard) {
if (((value&1)!=0) || (rest!=0)) {
++value; /* round */
if ((value >> 53) != 0) { /* carry all the way across */
value >>= 1; /* renormalize */
++bexp;
}
}
}
/*
* Check for overflow
* IEEE Double Precision Format
* (From Table 7-8 of Kane and Heinrich)
*
* Fraction bits 52
* Emax +1023
* Emin -1022
* Exponent bias +1023
* Exponent bits 11
* Integer bit hidden
* Total width in bits 64
*/
if (bexp > limits::max_exponent) { /* overflow */
return limits::infinity();
}
else { /* value is normal */
value &= ~(ULL(1) << (limits::digits - 1)); /* hide hidden bit */
_Stl_set_exponent(value, bexp + 1022); /* add bias */
}
}
_STLP_STATIC_ASSERT(sizeof(uint64) >= sizeof(double))
return drep.val;
}
#endif
#if defined (__linux__) || defined (__MINGW32__) || defined (__CYGWIN__) || \
defined (__BORLANDC__) || defined (__DMC__) || defined (__HP_aCC)
template <class D, class IEEE, int M, int BIAS>
D _Stl_atodT(char *buffer, ptrdiff_t ndigit, int dexp)
{
typedef numeric_limits<D> limits;
/* Convert the decimal digits to a binary integer. */
char *bufferend = buffer + ndigit; /* pointer to char after last digit */
_ll vv;
vv.i64 = 0L;
while ( buffer < bufferend ) {
vv.i64 *= 10;
vv.i64 += *buffer++;
}
if ( vv.i64 == ULL(0) ) { /* Check for zero and treat it as a special case */
return D(0.0);
}
/* Normalize value */
int bexp = 64; /* convert from 64b int to fraction */
/* Count number of non-zeroes in value */
int nzero = 0;
if ((vv.i64 >> 32) != 0) { nzero = 32; }
if ((vv.i64 >> (16 + nzero)) != 0) { nzero += 16; }
if ((vv.i64 >> ( 8 + nzero)) != 0) { nzero += 8; }
if ((vv.i64 >> ( 4 + nzero)) != 0) { nzero += 4; }
if ((vv.i64 >> ( 2 + nzero)) != 0) { nzero += 2; }
if ((vv.i64 >> ( 1 + nzero)) != 0) { nzero += 1; }
if ((vv.i64 >> ( nzero)) != 0) { nzero += 1; }
/* Normalize */
nzero = 64 - nzero;
vv.i64 <<= nzero; // * TY 03/25/2000 - removed extraneous cast to uint64
bexp -= nzero;
/* At this point we have a 64b fraction and a binary exponent
* but have yet to incorporate the decimal exponent.
*/
/* multiply by 10^dexp */
int sexp;
_Stl_tenscale(vv.i64, dexp, sexp);
bexp += sexp;
if ( bexp >= limits::min_exponent ) { /* not zero or denorm */
if ( limits::digits < 64 ) {
/* Round to (64 - M + 1) bits */
uint64_t rest = vv.i64 & ((~ULL(0) / ULL(2)) >> (limits::digits - 1));
vv.i64 >>= M - 2;
uint32_t guard = (uint32) vv.i64 & 1;
vv.i64 >>= 1;
/* value&1 guard rest Action
*
* dc 0 dc none
* 1 1 dc round
* 0 1 0 none
* 0 1 !=0 round
*/
if (guard) {
if ( ((vv.i64 & 1) != 0) || (rest != 0) ) {
vv.i64++; /* round */
if ( (vv.i64 >> (limits::digits < 64 ? limits::digits : 0)) != 0 ) { /* carry all the way across */
vv.i64 >>= 1; /* renormalize */
++bexp;
}
}
}
vv.i64 &= ~(ULL(1) << (limits::digits - 1)); /* hide hidden bit */
}
/*
* Check for overflow
* IEEE Double Precision Format
* (From Table 7-8 of Kane and Heinrich)
*
* Fraction bits 52
* Emax +1023
* Emin -1022
* Exponent bias +1023
* Exponent bits 11
* Integer bit hidden
* Total width in bits 64
*/
if (bexp > limits::max_exponent) { /* overflow */
return limits::infinity();
}
/* value is normal */
IEEE v;
v.ieee.mantissa0 = vv.i32.hi;
v.ieee.mantissa1 = vv.i32.lo;
v.ieee.negative = 0;
v.ieee.exponent = bexp + BIAS - 1;
return v.d;
}
/* HI denorm or underflow */
bexp += BIAS - 1;
if (bexp < -limits::digits) { /* guaranteed underflow */
vv.i64 = 0;
} else { /* denorm or possible underflow */
/*
* Problem point for long double: looks like this code reflect shareing of mantissa
* and exponent in 64b int; not so for long double
*/
int lead0 = M - bexp; /* M = 12 sign and exponent bits */
uint64_t rest;
uint32_t guard;
/* we must special case right shifts of more than 63 */
if (lead0 > 64) {
rest = vv.i64;
guard = 0;
vv.i64 = 0;
} else if (lead0 == 64) {
rest = vv.i64 & ((ULL(1) << 63)-1);
guard = (uint32) ((vv.i64 >> 63) & 1 );
vv.i64 = 0;
} else {
rest = vv.i64 & (((ULL(1) << lead0)-1)-1);
guard = (uint32) (((vv.i64 >> lead0)-1) & 1);
vv.i64 >>= /*(uint64)*/ lead0; /* exponent is zero */
}
/* Round */
if (guard && ( (vv.i64 & 1) || rest)) {
vv.i64++;
if (vv.i64 == (ULL(1) << (limits::digits - 1))) { /* carry created normal number */
IEEE v;
v.ieee.mantissa0 = 0;
v.ieee.mantissa1 = 0;
v.ieee.negative = 0;
v.ieee.exponent = 1;
return v.d;
}
}
}
IEEE v;
v.ieee.mantissa0 = vv.i32.hi;
v.ieee.mantissa1 = vv.i32.lo;
v.ieee.negative = 0;
v.ieee.exponent = 0;
return v.d;
}
#endif // __linux__
#ifndef __linux__
static double _Stl_string_to_double(const char *s) {
typedef numeric_limits<double> limits;
const int max_digits = limits::digits10 + 2;
unsigned c;
unsigned Negate, decimal_point;
char *d;
int exp;
int dpchar;
char digits[max_digits];
c = *s++;
/* process sign */
Negate = 0;
if (c == '+') {
c = *s++;
} else if (c == '-') {
Negate = 1;
c = *s++;
}
d = digits;
dpchar = '.' - '0';
decimal_point = 0;
exp = 0;
for (;;) {
c -= '0';
if (c < 10) {
if (d == digits + max_digits) {
/* ignore more than max_digits digits, but adjust exponent */
exp += (decimal_point ^ 1);
} else {
if (c == 0 && d == digits) {
/* ignore leading zeros */
} else {
*d++ = (char) c;
}
exp -= decimal_point;
}
} else if (c == (unsigned int) dpchar && !decimal_point) { /* INTERNATIONAL */
decimal_point = 1;
} else {
break;
}
c = *s++;
}
/* strtod cant return until it finds the end of the exponent */
if (d == digits) {
return 0.0;
}
if (c == 'e' - '0' || c == 'E' - '0') {
register unsigned negate_exp = 0;
register int e = 0;
c = *s++;
if (c == '+' || c == ' ') {
c = *s++;
} else if (c == '-') {
negate_exp = 1;
c = *s++;
}
if (c -= '0', c < 10) {
do {
e = e * 10 + (int)c;
c = *s++;
} while (c -= '0', c < 10);
if (negate_exp) {
e = -e;
}
exp += e;
}
}
double x;
ptrdiff_t n = d - digits;
if ((exp + n - 1) < limits::min_exponent10) {
x = 0;
}
else if ((exp + n - 1) > limits::max_exponent10) {
x = limits::infinity();
}
else {
/* Let _Stl_atod diagnose under- and over-flows.
* If the input was == 0.0, we have already returned,
* so retval of +-Inf signals OVERFLOW, 0.0 UNDERFLOW */
x = _Stl_atod(digits, n, exp);
}
if (Negate) {
x = -x;
}
return x;
}
#endif
#if defined (__linux__) || defined (__MINGW32__) || defined (__CYGWIN__) || \
defined (__BORLANDC__) || defined (__DMC__) || defined (__HP_aCC)
template <class D, class IEEE, int M, int BIAS>
D _Stl_string_to_doubleT(const char *s)
{
typedef numeric_limits<D> limits;
const int max_digits = limits::digits10; /* + 2 17 */;
unsigned c;
unsigned decimal_point;
char *d;
int exp;
D x;
int dpchar;
char digits[max_digits];
c = *s++;
/* process sign */
bool Negate = false;
if (c == '+') {
c = *s++;
} else if (c == '-') {
Negate = true;
c = *s++;
}
d = digits;
dpchar = '.' - '0';
decimal_point = 0;
exp = 0;
for (;;) {
c -= '0';
if (c < 10) {
if (d == digits + max_digits) {
/* ignore more than max_digits digits, but adjust exponent */
exp += (decimal_point ^ 1);
} else {
if (c == 0 && d == digits) {
/* ignore leading zeros */
} else {
*d++ = (char) c;
}
exp -= decimal_point;
}
} else if (c == (unsigned int) dpchar && !decimal_point) { /* INTERNATIONAL */
decimal_point = 1;
} else {
break;
}
c = *s++;
}
/* strtod cant return until it finds the end of the exponent */
if (d == digits) {
return D(0.0);
}
if (c == 'e'-'0' || c == 'E'-'0') {
bool negate_exp = false;
register int e = 0;
c = *s++;
if (c == '+' || c == ' ') {
c = *s++;
} else if (c == '-') {
negate_exp = true;
c = *s++;
}
if (c -= '0', c < 10) {
do {
e = e * 10 + (int)c;
c = *s++;
} while (c -= '0', c < 10);
if (negate_exp) {
e = -e;
}
exp += e;
}
}
ptrdiff_t n = d - digits;
if ((exp + n - 1) < limits::min_exponent10) {
return D(0.0); // +0.0 is the same as -0.0
} else if ((exp + n - 1) > limits::max_exponent10 ) {
// not good, because of x = -x below; this may lead to portability problems
x = limits::infinity();
} else {
/* let _Stl_atod diagnose under- and over-flows */
/* if the input was == 0.0, we have already returned,
so retval of +-Inf signals OVERFLOW, 0.0 UNDERFLOW
*/
x = _Stl_atodT<D,IEEE,M,BIAS>(digits, n, exp);
}
return Negate ? -x : x;
}
#endif // __linux__
void _STLP_CALL
__string_to_float(const __iostring& v, float& val)
{
#if !defined (__linux__)
val = (float)_Stl_string_to_double(v.c_str());
#else
val = (float)_Stl_string_to_doubleT<double,ieee754_double,12,IEEE754_DOUBLE_BIAS>(v.c_str());
#endif
}
void _STLP_CALL
__string_to_float(const __iostring& v, double& val)
{
#if !defined (__linux__)
val = _Stl_string_to_double(v.c_str());
#else
val = _Stl_string_to_doubleT<double,ieee754_double,12,IEEE754_DOUBLE_BIAS>(v.c_str());
#endif
}
#if !defined (_STLP_NO_LONG_DOUBLE)
void _STLP_CALL
__string_to_float(const __iostring& v, long double& val) {
#if !defined (__linux__) && !defined (__MINGW32__) && !defined (__CYGWIN__) && \
!defined (__BORLANDC__) && !defined (__DMC__) && !defined (__HP_aCC)
//The following function is valid only if long double is an alias for double.
_STLP_STATIC_ASSERT( sizeof(long double) <= sizeof(double) )
val = _Stl_string_to_double(v.c_str());
#else
val = _Stl_string_to_doubleT<long double,ieee854_long_double,16,IEEE854_LONG_DOUBLE_BIAS>(v.c_str());
#endif
}
#endif
_STLP_MOVE_TO_STD_NAMESPACE
_STLP_END_NAMESPACE
// Local Variables:
// mode:C++
// End:
Reference in a new issue Copy permalink