352 lines
6.6 KiB
C
352 lines
6.6 KiB
C
/****************************************************************
|
|
|
|
The author of this software is David M. Gay.
|
|
|
|
Copyright (C) 1998 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 "."). */
|
|
|
|
#include <_ansi.h>
|
|
#include <reent.h>
|
|
#include <string.h>
|
|
#include "mprec.h"
|
|
#include "gdtoa.h"
|
|
#include "gd_qnan.h"
|
|
|
|
#ifdef USE_LOCALE
|
|
#include "locale.h"
|
|
#endif
|
|
|
|
unsigned char hexdig[256];
|
|
|
|
static void
|
|
_DEFUN (htinit, (h, s, inc),
|
|
unsigned char *h _AND
|
|
unsigned char *s _AND
|
|
int inc)
|
|
{
|
|
int i, j;
|
|
for(i = 0; (j = s[i]) !=0; i++)
|
|
h[j] = i + inc;
|
|
}
|
|
|
|
void
|
|
_DEFUN_VOID (hexdig_init)
|
|
{
|
|
#define USC (unsigned char *)
|
|
htinit(hexdig, USC "0123456789", 0x10);
|
|
htinit(hexdig, USC "abcdef", 0x10 + 10);
|
|
htinit(hexdig, USC "ABCDEF", 0x10 + 10);
|
|
}
|
|
|
|
static void
|
|
_DEFUN(rshift, (b, k),
|
|
_Bigint *b _AND
|
|
int k)
|
|
{
|
|
__ULong *x, *x1, *xe, y;
|
|
int n;
|
|
|
|
x = x1 = b->_x;
|
|
n = k >> kshift;
|
|
if (n < b->_wds) {
|
|
xe = x + b->_wds;
|
|
x += n;
|
|
if (k &= kmask) {
|
|
n = ULbits - k;
|
|
y = *x++ >> k;
|
|
while(x < xe) {
|
|
*x1++ = (y | (*x << n)) & ALL_ON;
|
|
y = *x++ >> k;
|
|
}
|
|
if ((*x1 = y) !=0)
|
|
x1++;
|
|
}
|
|
else
|
|
while(x < xe)
|
|
*x1++ = *x++;
|
|
}
|
|
if ((b->_wds = x1 - b->_x) == 0)
|
|
b->_x[0] = 0;
|
|
}
|
|
|
|
static _Bigint *
|
|
_DEFUN (increment, (ptr, b),
|
|
struct _reent *ptr _AND
|
|
_Bigint *b)
|
|
{
|
|
__ULong *x, *xe;
|
|
_Bigint *b1;
|
|
#ifdef Pack_16
|
|
__ULong carry = 1, y;
|
|
#endif
|
|
|
|
x = b->_x;
|
|
xe = x + b->_wds;
|
|
#ifdef Pack_32
|
|
do {
|
|
if (*x < (__ULong)0xffffffffL) {
|
|
++*x;
|
|
return b;
|
|
}
|
|
*x++ = 0;
|
|
} while(x < xe);
|
|
#else
|
|
do {
|
|
y = *x + carry;
|
|
carry = y >> 16;
|
|
*x++ = y & 0xffff;
|
|
if (!carry)
|
|
return b;
|
|
} while(x < xe);
|
|
if (carry)
|
|
#endif
|
|
{
|
|
if (b->_wds >= b->_maxwds) {
|
|
b1 = Balloc(ptr, b->_k+1);
|
|
Bcopy(b1, b);
|
|
Bfree(ptr, b);
|
|
b = b1;
|
|
}
|
|
b->_x[b->_wds++] = 1;
|
|
}
|
|
return b;
|
|
}
|
|
|
|
|
|
int
|
|
_DEFUN(gethex, (ptr, sp, fpi, exp, bp, sign),
|
|
struct _reent *ptr _AND
|
|
_CONST char **sp _AND
|
|
FPI *fpi _AND
|
|
Long *exp _AND
|
|
_Bigint **bp _AND
|
|
int sign)
|
|
{
|
|
_Bigint *b;
|
|
_CONST unsigned char *decpt, *s0, *s, *s1;
|
|
int esign, havedig, irv, k, n, nbits, up, zret;
|
|
__ULong L, lostbits, *x;
|
|
Long e, e1;
|
|
#ifdef USE_LOCALE
|
|
unsigned char decimalpoint = *localeconv()->decimal_point;
|
|
#else
|
|
#define decimalpoint '.'
|
|
#endif
|
|
|
|
if (!hexdig['0'])
|
|
hexdig_init();
|
|
havedig = 0;
|
|
s0 = *(_CONST unsigned char **)sp + 2;
|
|
while(s0[havedig] == '0')
|
|
havedig++;
|
|
s0 += havedig;
|
|
s = s0;
|
|
decpt = 0;
|
|
zret = 0;
|
|
e = 0;
|
|
if (!hexdig[*s]) {
|
|
zret = 1;
|
|
if (*s != decimalpoint)
|
|
goto pcheck;
|
|
decpt = ++s;
|
|
if (!hexdig[*s])
|
|
goto pcheck;
|
|
while(*s == '0')
|
|
s++;
|
|
if (hexdig[*s])
|
|
zret = 0;
|
|
havedig = 1;
|
|
s0 = s;
|
|
}
|
|
while(hexdig[*s])
|
|
s++;
|
|
if (*s == decimalpoint && !decpt) {
|
|
decpt = ++s;
|
|
while(hexdig[*s])
|
|
s++;
|
|
}
|
|
if (decpt)
|
|
e = -(((Long)(s-decpt)) << 2);
|
|
pcheck:
|
|
s1 = s;
|
|
switch(*s) {
|
|
case 'p':
|
|
case 'P':
|
|
esign = 0;
|
|
switch(*++s) {
|
|
case '-':
|
|
esign = 1;
|
|
/* no break */
|
|
case '+':
|
|
s++;
|
|
}
|
|
if ((n = hexdig[*s]) == 0 || n > 0x19) {
|
|
s = s1;
|
|
break;
|
|
}
|
|
e1 = n - 0x10;
|
|
while((n = hexdig[*++s]) !=0 && n <= 0x19)
|
|
e1 = 10*e1 + n - 0x10;
|
|
if (esign)
|
|
e1 = -e1;
|
|
e += e1;
|
|
}
|
|
*sp = (char*)s;
|
|
if (zret)
|
|
return havedig ? STRTOG_Zero : STRTOG_NoNumber;
|
|
n = s1 - s0 - 1;
|
|
for(k = 0; n > 7; n >>= 1)
|
|
k++;
|
|
b = Balloc(ptr, k);
|
|
x = b->_x;
|
|
n = 0;
|
|
L = 0;
|
|
while(s1 > s0) {
|
|
if (*--s1 == decimalpoint)
|
|
continue;
|
|
if (n == 32) {
|
|
*x++ = L;
|
|
L = 0;
|
|
n = 0;
|
|
}
|
|
L |= (hexdig[*s1] & 0x0f) << n;
|
|
n += 4;
|
|
}
|
|
*x++ = L;
|
|
b->_wds = n = x - b->_x;
|
|
n = 32*n - hi0bits(L);
|
|
nbits = fpi->nbits;
|
|
lostbits = 0;
|
|
x = b->_x;
|
|
if (n > nbits) {
|
|
n -= nbits;
|
|
if (any_on(b,n)) {
|
|
lostbits = 1;
|
|
k = n - 1;
|
|
if (x[k>>kshift] & 1 << (k & kmask)) {
|
|
lostbits = 2;
|
|
if (k > 1 && any_on(b,k-1))
|
|
lostbits = 3;
|
|
}
|
|
}
|
|
rshift(b, n);
|
|
e += n;
|
|
}
|
|
else if (n < nbits) {
|
|
n = nbits - n;
|
|
b = lshift(ptr, b, n);
|
|
e -= n;
|
|
x = b->_x;
|
|
}
|
|
if (e > fpi->emax) {
|
|
ovfl:
|
|
Bfree(ptr, b);
|
|
*bp = 0;
|
|
return STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;
|
|
}
|
|
irv = STRTOG_Normal;
|
|
if (e < fpi->emin) {
|
|
irv = STRTOG_Denormal;
|
|
n = fpi->emin - e;
|
|
if (n >= nbits) {
|
|
switch (fpi->rounding) {
|
|
case FPI_Round_near:
|
|
if (n == nbits && (n < 2 || any_on(b,n-1)))
|
|
goto one_bit;
|
|
break;
|
|
case FPI_Round_up:
|
|
if (!sign)
|
|
goto one_bit;
|
|
break;
|
|
case FPI_Round_down:
|
|
if (sign) {
|
|
one_bit:
|
|
*exp = fpi->emin;
|
|
x[0] = b->_wds = 1;
|
|
*bp = b;
|
|
return STRTOG_Denormal | STRTOG_Inexhi
|
|
| STRTOG_Underflow;
|
|
}
|
|
}
|
|
Bfree(ptr, b);
|
|
*bp = 0;
|
|
return STRTOG_Zero | STRTOG_Inexlo | STRTOG_Underflow;
|
|
}
|
|
k = n - 1;
|
|
if (lostbits)
|
|
lostbits = 1;
|
|
else if (k > 0)
|
|
lostbits = any_on(b,k);
|
|
if (x[k>>kshift] & 1 << (k & kmask))
|
|
lostbits |= 2;
|
|
nbits -= n;
|
|
rshift(b,n);
|
|
e = fpi->emin;
|
|
}
|
|
if (lostbits) {
|
|
up = 0;
|
|
switch(fpi->rounding) {
|
|
case FPI_Round_zero:
|
|
break;
|
|
case FPI_Round_near:
|
|
if ((lostbits & 2)
|
|
&& ((lostbits & 1) | (x[0] & 1)))
|
|
up = 1;
|
|
break;
|
|
case FPI_Round_up:
|
|
up = 1 - sign;
|
|
break;
|
|
case FPI_Round_down:
|
|
up = sign;
|
|
}
|
|
if (up) {
|
|
k = b->_wds;
|
|
b = increment(ptr, b);
|
|
x = b->_x;
|
|
if (irv == STRTOG_Denormal) {
|
|
if (nbits == fpi->nbits - 1
|
|
&& x[nbits >> kshift] & 1 << (nbits & kmask))
|
|
irv = STRTOG_Normal;
|
|
}
|
|
else if ((b->_wds > k)
|
|
|| ((n = nbits & kmask) !=0
|
|
&& (hi0bits(x[k-1]) < 32-n))) {
|
|
rshift(b,1);
|
|
if (++e > fpi->emax)
|
|
goto ovfl;
|
|
}
|
|
irv |= STRTOG_Inexhi;
|
|
}
|
|
else
|
|
irv |= STRTOG_Inexlo;
|
|
}
|
|
*bp = b;
|
|
*exp = e;
|
|
return irv;
|
|
}
|
|
|