355 lines
		
	
	
		
			7.6 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			355 lines
		
	
	
		
			7.6 KiB
		
	
	
	
		
			C
		
	
	
	
| /****************************************************************
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| 
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| The author of this software is David M. Gay.
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| 
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| Copyright (C) 1998 by Lucent Technologies
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| All Rights Reserved
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| 
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| Permission to use, copy, modify, and distribute this software and
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| its documentation for any purpose and without fee is hereby
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| granted, provided that the above copyright notice appear in all
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| copies and that both that the copyright notice and this
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| permission notice and warranty disclaimer appear in supporting
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| documentation, and that the name of Lucent or any of its entities
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| not be used in advertising or publicity pertaining to
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| distribution of the software without specific, written prior
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| permission.
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| 
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| LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
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| INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
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| IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
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| SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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| WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
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| IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
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| ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
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| THIS SOFTWARE.
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| 
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| ****************************************************************/
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| 
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| /* Please send bug reports to David M. Gay (dmg at acm dot org,
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|  * with " at " changed at "@" and " dot " changed to ".").	*/
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| 
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| #include <_ansi.h>
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| #include <reent.h>
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| #include <string.h>
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| #include <locale.h>
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| #include "mprec.h"
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| #include "gdtoa.h"
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| #include "gd_qnan.h"
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| 
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| #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) && !defined(_SMALL_HEXDIG)
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| const unsigned char __hexdig[256]=
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| {
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	16,17,18,19,20,21,22,23,24,25,0,0,0,0,0,0,
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| 	0,26,27,28,29,30,31,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,26,27,28,29,30,31,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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| 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
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| };
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| #else /* !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) && !defined(_SMALL_HEXDIG) */
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| unsigned char
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| __hexdig_fun (unsigned char c)
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| {
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| 	if(c>='0' && c<='9') return c-'0'+0x10;
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| 	else if(c>='a' && c<='f') return c-'a'+0x10+10;
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| 	else if(c>='A' && c<='F') return c-'A'+0x10+10;
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| 	else return 0;
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| }
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| #endif /* !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) && !defined(_SMALL_HEXDIG) */
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| 
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| static void
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| rshift (_Bigint *b,
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| 	int k)
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| {
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| 	__ULong *x, *x1, *xe, y;
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| 	int n;
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| 
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| 	x = x1 = b->_x;
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| 	n = k >> kshift;
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| 	if (n < b->_wds) {
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| 		xe = x + b->_wds;
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| 		x += n;
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| 		if (k &= kmask) {
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| 			n = ULbits - k;
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| 			y = *x++ >> k;
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| 			while(x < xe) {
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| 				*x1++ = (y | (*x << n)) & ALL_ON;
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| 				y = *x++ >> k;
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| 				}
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| 			if ((*x1 = y) !=0)
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| 				x1++;
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| 			}
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| 		else
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| 			while(x < xe)
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| 				*x1++ = *x++;
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| 		}
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| 	if ((b->_wds = x1 - b->_x) == 0)
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| 		b->_x[0] = 0;
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| }
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| 
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| static _Bigint *
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| increment (struct _reent *ptr,
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| 	_Bigint *b)
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| {
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| 	__ULong *x, *xe;
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| 	_Bigint *b1;
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| #ifdef Pack_16
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| 	__ULong carry = 1, y;
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| #endif
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| 
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| 	x = b->_x;
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| 	xe = x + b->_wds;
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| #ifdef Pack_32
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| 	do {
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| 		if (*x < (__ULong)0xffffffffL) {
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| 			++*x;
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| 			return b;
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| 			}
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| 		*x++ = 0;
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| 		} while(x < xe);
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| #else
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| 	do {
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| 		y = *x + carry;
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| 		carry = y >> 16;
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| 		*x++ = y & 0xffff;
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| 		if (!carry)
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| 			return b;
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| 		} while(x < xe);
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| 	if (carry)
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| #endif
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| 	{
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| 		if (b->_wds >= b->_maxwds) {
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| 			b1 = Balloc(ptr, b->_k+1);
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| 			Bcopy(b1, b);
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| 			Bfree(ptr, b);
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| 			b = b1;
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| 			}
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| 		b->_x[b->_wds++] = 1;
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| 		}
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| 	return b;
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| }
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| 
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| 
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| int
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| gethex (struct _reent *ptr, const char **sp, const FPI *fpi,
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| 	Long *exp, _Bigint **bp, int sign, locale_t loc)
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| {
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| 	_Bigint *b;
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| 	const unsigned char *decpt, *s0, *s, *s1;
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| 	int esign, havedig, irv, k, n, nbits, up, zret;
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| 	__ULong L, lostbits, *x;
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| 	Long e, e1;
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| 	unsigned char *decimalpoint = (unsigned char *)
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| 				      __localeconv_l (loc)->decimal_point;
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| 	size_t decp_len = strlen ((const char *) decimalpoint);
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| 	unsigned char decp_end = decimalpoint[decp_len - 1];
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| 
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| 	havedig = 0;
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| 	s0 = *(const unsigned char **)sp + 2;
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| 	while(s0[havedig] == '0')
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| 		havedig++;
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| 	s0 += havedig;
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| 	s = s0;
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| 	decpt = 0;
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| 	zret = 0;
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| 	e = 0;
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| 	if (!__get_hexdig(*s)) {
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| 		zret = 1;
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| 		if (strncmp ((const char *) s, (const char *) decimalpoint,
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| 			     decp_len) != 0)
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| 			goto pcheck;
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| 		decpt = (s += decp_len);
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| 		if (!__get_hexdig(*s))
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| 			goto pcheck;
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| 		while(*s == '0')
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| 			s++;
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| 		if (__get_hexdig(*s))
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| 			zret = 0;
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| 		havedig = 1;
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| 		s0 = s;
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| 		}
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| 	while(__get_hexdig(*s))
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| 		s++;
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| 	if (strncmp ((const char *) s, (const char *) decimalpoint,
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| 		     decp_len) == 0
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| 	    && !decpt) {
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| 		decpt = (s += decp_len);
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| 		while(__get_hexdig(*s))
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| 			s++;
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| 		}
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| 	if (decpt)
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| 		e = -(((Long)(s-decpt)) << 2);
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|  pcheck:
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| 	s1 = s;
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| 	switch(*s) {
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| 	  case 'p':
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| 	  case 'P':
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| 		esign = 0;
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| 		switch(*++s) {
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| 		  case '-':
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| 			esign = 1;
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| 			/* no break */
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| 		  case '+':
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| 			s++;
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| 		  }
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| 		if ((n = __get_hexdig(*s)) == 0 || n > 0x19) {
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| 			s = s1;
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| 			break;
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| 			}
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| 		e1 = n - 0x10;
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| 		while((n = __get_hexdig(*++s)) !=0 && n <= 0x19)
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| 			e1 = 10*e1 + n - 0x10;
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| 		if (esign)
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| 			e1 = -e1;
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| 		e += e1;
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| 	  }
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| 	*sp = (char*)s;
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| 	if (zret)
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| 		return havedig ? STRTOG_Zero : STRTOG_NoNumber;
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| 	n = s1 - s0 - 1;
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| 	for(k = 0; n > 7; n >>= 1)
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| 		k++;
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| 	b = Balloc(ptr, k);
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| 	x = b->_x;
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| 	n = 0;
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| 	L = 0;
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| 	while(s1 > s0) {
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| 		if (*--s1 == decp_end && s1 - decp_len + 1 >= s0
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| 		    && strncmp ((const char *) s1 - decp_len + 1,
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| 				(const char *) decimalpoint, decp_len) == 0) {
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| 			s1 -= decp_len - 1; /* Note the --s1 above! */
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| 			continue;
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| 		}
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| 		if (n == 32) {
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| 			*x++ = L;
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| 			L = 0;
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| 			n = 0;
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| 			}
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| 		L |= (__get_hexdig(*s1) & 0x0f) << n;
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| 		n += 4;
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| 		}
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| 	*x++ = L;
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| 	b->_wds = n = x - b->_x;
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| 	n = 32*n - hi0bits(L);
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| 	nbits = fpi->nbits;
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| 	lostbits = 0;
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| 	x = b->_x;
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| 	if (n > nbits) {
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| 		n -= nbits;
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| 		if (any_on(b,n)) {
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| 			lostbits = 1;
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| 			k = n - 1;
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| 			if (x[k>>kshift] & 1 << (k & kmask)) {
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| 				lostbits = 2;
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| 				if (k > 1 && any_on(b,k-1))
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| 					lostbits = 3;
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| 				}
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| 			}
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| 		rshift(b, n);
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| 		e += n;
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| 		}
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| 	else if (n < nbits) {
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| 		n = nbits - n;
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| 		b = lshift(ptr, b, n);
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| 		e -= n;
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| 		x = b->_x;
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| 		}
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| 	if (e > fpi->emax) {
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|  ovfl:
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| 		Bfree(ptr, b);
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| 		*bp = 0;
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| 		return STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;
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| 		}
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| 	irv = STRTOG_Normal;
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| 	if (e < fpi->emin) {
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| 		irv = STRTOG_Denormal;
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| 		n = fpi->emin - e;
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| 		if (n >= nbits) {
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| 			switch (fpi->rounding) {
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| 			  case FPI_Round_near:
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| 				if (n == nbits && (n < 2 || any_on(b,n-1)))
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| 					goto one_bit;
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| 				break;
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| 			  case FPI_Round_up:
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| 				if (!sign)
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| 					goto one_bit;
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| 				break;
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| 			  case FPI_Round_down:
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| 				if (sign) {
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|  one_bit:
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| 					*exp = fpi->emin;
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| 					x[0] = b->_wds = 1;
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| 					*bp = b;
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| 					return STRTOG_Denormal | STRTOG_Inexhi
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| 						| STRTOG_Underflow;
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| 					}
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| 			  }
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| 			Bfree(ptr, b);
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| 			*bp = 0;
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| 			return STRTOG_Zero | STRTOG_Inexlo | STRTOG_Underflow;
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| 			}
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| 		k = n - 1;
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| 		if (lostbits)
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| 			lostbits = 1;
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| 		else if (k > 0)
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| 			lostbits = any_on(b,k);
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| 		if (x[k>>kshift] & 1 << (k & kmask))
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| 			lostbits |= 2;
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| 		nbits -= n;
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| 		rshift(b,n);
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| 		e = fpi->emin;
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| 		}
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| 	if (lostbits) {
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| 		up = 0;
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| 		switch(fpi->rounding) {
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| 		  case FPI_Round_zero:
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| 			break;
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| 		  case FPI_Round_near:
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| 		    if ((lostbits & 2)
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| 			    && ((lostbits & 1) | (x[0] & 1)))
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| 				up = 1;
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| 			break;
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| 		  case FPI_Round_up:
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| 			up = 1 - sign;
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| 			break;
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| 		  case FPI_Round_down:
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| 			up = sign;
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| 		  }
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| 		if (up) {
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| 			k = b->_wds;
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| 			b = increment(ptr, b);
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| 			x = b->_x;
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| 			if (irv == STRTOG_Denormal) {
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| 				if (nbits == fpi->nbits - 1
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| 				 && x[nbits >> kshift] & 1 << (nbits & kmask))
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| 					irv =  STRTOG_Normal;
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| 				}
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| 			else if ((b->_wds > k)
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| 			 || ((n = nbits & kmask) !=0
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| 			     && (hi0bits(x[k-1]) < 32-n))) {
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| 				rshift(b,1);
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| 				if (++e > fpi->emax)
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| 					goto ovfl;
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| 				}
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| 			irv |= STRTOG_Inexhi;
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| 			}
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| 		else
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| 			irv |= STRTOG_Inexlo;
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| 		}
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| 	*bp = b;
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| 	*exp = e;
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| 	return irv;
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| }
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| 
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