/* This file is extracted from S L Moshier's ioldoubl.c,
* modified for use in MinGW
*
* Extended precision arithmetic functions for long double I/O.
* This program has been placed in the public domain.
*/
/*
* Revision history:
*
* 5 Jan 84 PDP-11 assembly language version
* 6 Dec 86 C language version
* 30 Aug 88 100 digit version, improved rounding
* 15 May 92 80-bit long double support
*
* Author: S. L. Moshier.
*
* 6 Oct 02 Modified for MinGW by inlining utility routines,
* removing global variables and splitting out strtold
* from _IO_ldtoa and _IO_ldtostr.
*
* 4 Feb 04 Reorganize __asctoe64 to fix setting error codes,
* and handling special chars.
*
* Danny Smith <[email protected]>
*/
#include "math/cephes_emath.h"
#if NE == 10
/* 1.0E0 */
static const unsigned short __eone[NE] =
{0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x8000, 0x3fff,};
#else
static const unsigned short __eone[NE] = {
0, 0000000,0000000,0000000,0100000,0x3fff,};
#endif
#if NE == 10
static const unsigned short __etens[NTEN + 1][NE] =
{
{0x6576, 0x4a92, 0x804a, 0x153f,
0xc94c, 0x979a, 0x8a20, 0x5202, 0xc460, 0x7525,}, /* 10**4096 */
{0x6a32, 0xce52, 0x329a, 0x28ce,
0xa74d, 0x5de4, 0xc53d, 0x3b5d, 0x9e8b, 0x5a92,}, /* 10**2048 */
{0x526c, 0x50ce, 0xf18b, 0x3d28,
0x650d, 0x0c17, 0x8175, 0x7586, 0xc976, 0x4d48,},
{0x9c66, 0x58f8, 0xbc50, 0x5c54,
0xcc65, 0x91c6, 0xa60e, 0xa0ae, 0xe319, 0x46a3,},
{0x851e, 0xeab7, 0x98fe, 0x901b,
0xddbb, 0xde8d, 0x9df9, 0xebfb, 0xaa7e, 0x4351,},
{0x0235, 0x0137, 0x36b1, 0x336c,
0xc66f, 0x8cdf, 0x80e9, 0x47c9, 0x93ba, 0x41a8,},
{0x50f8, 0x25fb, 0xc76b, 0x6b71,
0x3cbf, 0xa6d5, 0xffcf, 0x1f49, 0xc278, 0x40d3,},
{0x0000, 0x0000, 0x0000, 0x0000,
0xf020, 0xb59d, 0x2b70, 0xada8, 0x9dc5, 0x4069,},
{0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0400, 0xc9bf, 0x8e1b, 0x4034,},
{0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x2000, 0xbebc, 0x4019,},
{0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x9c40, 0x400c,},
{0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0xc800, 0x4005,},
{0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0xa000, 0x4002,}, /* 10**1 */
};
#else
static const unsigned short __etens[NTEN+1][NE] = {
{0xc94c,0x979a,0x8a20,0x5202,0xc460,0x7525,},/* 10**4096 */
{0xa74d,0x5de4,0xc53d,0x3b5d,0x9e8b,0x5a92,},/* 10**2048 */
{0x650d,0x0c17,0x8175,0x7586,0xc976,0x4d48,},
{0xcc65,0x91c6,0xa60e,0xa0ae,0xe319,0x46a3,},
{0xddbc,0xde8d,0x9df9,0xebfb,0xaa7e,0x4351,},
{0xc66f,0x8cdf,0x80e9,0x47c9,0x93ba,0x41a8,},
{0x3cbf,0xa6d5,0xffcf,0x1f49,0xc278,0x40d3,},
{0xf020,0xb59d,0x2b70,0xada8,0x9dc5,0x4069,},
{0x0000,0x0000,0x0400,0xc9bf,0x8e1b,0x4034,},
{0x0000,0x0000,0x0000,0x2000,0xbebc,0x4019,},
{0x0000,0x0000,0x0000,0x0000,0x9c40,0x400c,},
{0x0000,0x0000,0x0000,0x0000,0xc800,0x4005,},
{0x0000,0x0000,0x0000,0x0000,0xa000,0x4002,}, /* 10**1 */
};
#endif
int __asctoe64(const char * __restrict__ ss, short unsigned int * __restrict__ y)
{
unsigned short yy[NI], xt[NI], tt[NI];
int esign, decflg, nexp, exp, lost;
int k, c;
int valid_lead_string = 0;
int have_non_zero_mant = 0;
int prec = 0;
/* int trail = 0; */
long lexp;
unsigned short nsign = 0;
const unsigned short *p;
char *sp, *lstr;
char *s;
const char dec_sym = *(localeconv ()->decimal_point);
int lenldstr = 0;
/* Copy the input string. */
c = strlen (ss) + 2;
lstr = (char *) alloca (c);
s = (char *) ss;
while( isspace ((int)(unsigned char)*s)) /* skip leading spaces */
{
++s;
++lenldstr;
}
sp = lstr;
for( k=0; k<c; k++ )
{
if( (*sp++ = *s++) == '\0' )
break;
}
*sp = '\0';
s = lstr;
if (*s == '-')
{
nsign = 0xffff;
++s;
}
else if (*s == '+')
{
++s;
}
if (_strnicmp("INF", s , 3) == 0)
{
valid_lead_string = 1;
s += 3;
if ( _strnicmp ("INITY", s, 5) == 0)
s += 5;
__ecleaz(yy);
yy[E] = 0x7fff; /* infinity */
goto aexit;
}
else if(_strnicmp ("NAN", s, 3) == 0)
{
valid_lead_string = 1;
s += 3;
__enan_NI16( yy );
goto aexit;
}
/* FIXME: Handle case of strtold ("NAN(n_char_seq)",endptr) */
/* Now get some digits. */
lost = 0;
decflg = 0;
nexp = 0;
exp = 0;
__ecleaz( yy );
/* Ignore leading zeros */
while (*s == '0')
{
valid_lead_string = 1;
s++;
}
nxtcom:
k = *s - '0';
if( (k >= 0) && (k <= 9) )
{
#if 0
/* The use of a special char as a flag for trailing zeroes causes problems when input
actually contains the char */
/* Identify and strip trailing zeros after the decimal point. */
if( (trail == 0) && (decflg != 0) )
{
sp = s;
while( (*sp >= '0') && (*sp <= '9') )
++sp;
--sp;
while( *sp == '0' )
{
*sp-- = (char)-1;
trail++;
}
if( *s == (char)-1 )
goto donchr;
}
#endif
/* If enough digits were given to more than fill up the yy register,
* continuing until overflow into the high guard word yy[2]
* guarantees that there will be a roundoff bit at the top
* of the low guard word after normalization.
*/
if( yy[2] == 0 )
{
if( decflg )
nexp += 1; /* count digits after decimal point */
__eshup1( yy ); /* multiply current number by 10 */
__emovz( yy, xt );
__eshup1( xt );
__eshup1( xt );
__eaddm( xt, yy );
__ecleaz( xt );
xt[NI-2] = (unsigned short )k;
__eaddm( xt, yy );
}
else
{
/* Mark any lost non-zero digit. */
lost |= k;
/* Count lost digits before the decimal point. */
if (decflg == 0)
nexp -= 1;
}
have_non_zero_mant |= k;
prec ++;
/* goto donchr; */
}
else if (*s == dec_sym)
{
if( decflg )
goto daldone;
++decflg;
}
else if ((*s == 'E') || (*s == 'e') )
{
if (prec || valid_lead_string)
goto expnt;
else
goto daldone;
}
#if 0
else if (*s == (char)-1)
goto donchr;
#endif
else /* an invalid char */
goto daldone;
/* donchr: */
++s;
goto nxtcom;
/* Exponent interpretation */
expnt:
esign = 1;
exp = 0;
/* Save position in case we need to fall back. */
sp = s;
++s;
/* check for + or - */
if( *s == '-' )
{
esign = -1;
++s;
}
if( *s == '+' )
++s;
/* Check for valid exponent. */
if (!(*s >= '0' && *s <= '9'))
{
s = sp;
goto daldone;
}
while( (*s >= '0') && (*s <= '9') )
{
/* Stop modifying exp if we are going to overflow anyway,
but keep parsing the string. */
if (exp < 4978)
{
exp *= 10;
exp += *s - '0';
}
s++;
}
if( esign < 0 )
exp = -exp;
if (exp > 4977) /* maybe overflow */
{
__ecleaz(yy);
if (have_non_zero_mant)
yy[E] = 0x7fff;
goto aexit;
}
else if (exp < -4977) /* underflow */
{
__ecleaz(yy);
goto aexit;
}
daldone:
nexp = exp - nexp;
/* Pad trailing zeros to minimize power of 10, per IEEE spec. */
while( (nexp > 0) && (yy[2] == 0) )
{
__emovz( yy, xt );
__eshup1( xt );
__eshup1( xt );
__eaddm( yy, xt );
__eshup1( xt );
if( xt[2] != 0 )
break;
nexp -= 1;
__emovz( xt, yy );
}
if( (k = __enormlz(yy)) > NBITS )
{
__ecleaz(yy);
goto aexit;
}
lexp = (EXONE - 1 + NBITS) - k;
__emdnorm( yy, lost, 0, lexp, 64, NBITS );
/* convert to external format */
/* Multiply by 10**nexp. If precision is 64 bits,
* the maximum relative error incurred in forming 10**n
* for 0 <= n <= 324 is 8.2e-20, at 10**180.
* For 0 <= n <= 999, the peak relative error is 1.4e-19 at 10**947.
* For 0 >= n >= -999, it is -1.55e-19 at 10**-435.
*/
lexp = yy[E];
if( nexp == 0 )
{
k = 0;
goto expdon;
}
esign = 1;
if( nexp < 0 )
{
nexp = -nexp;
esign = -1;
if( nexp > 4096 )
{ /* Punt. Can't handle this without 2 divides. */
__emovi( __etens[0], tt );
lexp -= tt[E];
k = __edivm( tt, yy );
lexp += EXONE;
nexp -= 4096;
}
}
p = &__etens[NTEN][0];
__emov( __eone, xt );
exp = 1;
do
{
if( exp & nexp )
__emul( p, xt, xt );
p -= NE;
exp = exp + exp;
}
while( exp <= MAXP );
__emovi( xt, tt );
if( esign < 0 )
{
lexp -= tt[E];
k = __edivm( tt, yy );
lexp += EXONE;
}
else
{
lexp += tt[E];
k = __emulm( tt, yy );
lexp -= EXONE - 1;
}
expdon:
/* Round and convert directly to the destination type */
__emdnorm( yy, k, 0, lexp, 64, 64 );
aexit:
yy[0] = nsign;
__toe64( yy, y );
/* Check for overflow, undeflow */
if (have_non_zero_mant &&
(*((long double*) y) == 0.0L || isinf (*((long double*) y))))
errno = ERANGE;
if (prec || valid_lead_string)
return (lenldstr + (s - lstr));
return 0;
}
long double strtold (const char * __restrict__ s, char ** __restrict__ se)
{
int lenldstr;
union
{
unsigned short int us[6];
long double ld;
} xx = {{0}};
lenldstr = __asctoe64( s, xx.us);
if (se)
*se = (char*)s + lenldstr;
return xx.ld;
}