1 91c13e54 2004-02-29 devnull /*
  2 91c13e54 2004-02-29 devnull  * The authors of this software are Rob Pike and Ken Thompson.
  3 91c13e54 2004-02-29 devnull  *              Copyright (c) 2002 by Lucent Technologies.
  4 91c13e54 2004-02-29 devnull  * Permission to use, copy, modify, and distribute this software for any
  5 91c13e54 2004-02-29 devnull  * purpose without fee is hereby granted, provided that this entire notice
  6 91c13e54 2004-02-29 devnull  * is included in all copies of any software which is or includes a copy
  7 91c13e54 2004-02-29 devnull  * or modification of this software and in all copies of the supporting
  8 91c13e54 2004-02-29 devnull  * documentation for such software.
  9 91c13e54 2004-02-29 devnull  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
 10 91c13e54 2004-02-29 devnull  * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
 11 91c13e54 2004-02-29 devnull  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
 12 91c13e54 2004-02-29 devnull  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
 13 91c13e54 2004-02-29 devnull  */
 14 91c13e54 2004-02-29 devnull #include <stdlib.h>
 15 91c13e54 2004-02-29 devnull #include <math.h>
 16 91c13e54 2004-02-29 devnull #include <ctype.h>
 17 91c13e54 2004-02-29 devnull #include <stdlib.h>
 18 91c13e54 2004-02-29 devnull #include <string.h>
 19 91c13e54 2004-02-29 devnull #include <errno.h>
 20 91c13e54 2004-02-29 devnull #include "fmt.h"
 21 91c13e54 2004-02-29 devnull #include "nan.h"
 22 91c13e54 2004-02-29 devnull 
 23 91c13e54 2004-02-29 devnull #ifndef nelem
 24 91c13e54 2004-02-29 devnull #define nelem(x)	(sizeof(x)/sizeof *(x))
 25 91c13e54 2004-02-29 devnull #endif
 26 91c13e54 2004-02-29 devnull #define nil ((void*)0)
 27 91c13e54 2004-02-29 devnull #define ulong _fmtulong
 28 91c13e54 2004-02-29 devnull typedef unsigned long ulong;
 29 91c13e54 2004-02-29 devnull 
 30 91c13e54 2004-02-29 devnull static ulong
 31 91c13e54 2004-02-29 devnull umuldiv(ulong a, ulong b, ulong c)
 32 91c13e54 2004-02-29 devnull {
 33 91c13e54 2004-02-29 devnull 	double d;
 34 91c13e54 2004-02-29 devnull 
 35 91c13e54 2004-02-29 devnull 	d = ((double)a * (double)b) / (double)c;
 36 91c13e54 2004-02-29 devnull 	if(d >= 4294967295.)
 37 91c13e54 2004-02-29 devnull 		d = 4294967295.;
 38 91c13e54 2004-02-29 devnull 	return (ulong)d;
 39 91c13e54 2004-02-29 devnull }
 40 91c13e54 2004-02-29 devnull 
 41 91c13e54 2004-02-29 devnull /*
 42 91c13e54 2004-02-29 devnull  * This routine will convert to arbitrary precision
 43 91c13e54 2004-02-29 devnull  * floating point entirely in multi-precision fixed.
 44 91c13e54 2004-02-29 devnull  * The answer is the closest floating point number to
 45 91c13e54 2004-02-29 devnull  * the given decimal number. Exactly half way are
 46 91c13e54 2004-02-29 devnull  * rounded ala ieee rules.
 47 91c13e54 2004-02-29 devnull  * Method is to scale input decimal between .500 and .999...
 48 91c13e54 2004-02-29 devnull  * with external power of 2, then binary search for the
 49 91c13e54 2004-02-29 devnull  * closest mantissa to this decimal number.
 50 91c13e54 2004-02-29 devnull  * Nmant is is the required precision. (53 for ieee dp)
 51 91c13e54 2004-02-29 devnull  * Nbits is the max number of bits/word. (must be <= 28)
 52 91c13e54 2004-02-29 devnull  * Prec is calculated - the number of words of fixed mantissa.
 53 91c13e54 2004-02-29 devnull  */
 54 91c13e54 2004-02-29 devnull enum
 55 91c13e54 2004-02-29 devnull {
 56 91c13e54 2004-02-29 devnull 	Nbits	= 28,				/* bits safely represented in a ulong */
 57 91c13e54 2004-02-29 devnull 	Nmant	= 53,				/* bits of precision required */
 58 91c13e54 2004-02-29 devnull 	Prec	= (Nmant+Nbits+1)/Nbits,	/* words of Nbits each to represent mantissa */
 59 91c13e54 2004-02-29 devnull 	Sigbit	= 1<<(Prec*Nbits-Nmant),	/* first significant bit of Prec-th word */
 60 91c13e54 2004-02-29 devnull 	Ndig	= 1500,
 61 91c13e54 2004-02-29 devnull 	One	= (ulong)(1<<Nbits),
 62 91c13e54 2004-02-29 devnull 	Half	= (ulong)(One>>1),
 63 91c13e54 2004-02-29 devnull 	Maxe	= 310,
 64 91c13e54 2004-02-29 devnull 
 65 91c13e54 2004-02-29 devnull 	Fsign	= 1<<0,		/* found - */
 66 91c13e54 2004-02-29 devnull 	Fesign	= 1<<1,		/* found e- */
 67 91c13e54 2004-02-29 devnull 	Fdpoint	= 1<<2,		/* found . */
 68 91c13e54 2004-02-29 devnull 
 69 91c13e54 2004-02-29 devnull 	S0	= 0,		/* _		_S0	+S1	#S2	.S3 */
 70 91c13e54 2004-02-29 devnull 	S1,			/* _+		#S2	.S3 */
 71 91c13e54 2004-02-29 devnull 	S2,			/* _+#		#S2	.S4	eS5 */
 72 91c13e54 2004-02-29 devnull 	S3,			/* _+.		#S4 */
 73 91c13e54 2004-02-29 devnull 	S4,			/* _+#.#	#S4	eS5 */
 74 91c13e54 2004-02-29 devnull 	S5,			/* _+#.#e	+S6	#S7 */
 75 91c13e54 2004-02-29 devnull 	S6,			/* _+#.#e+	#S7 */
 76 91c13e54 2004-02-29 devnull 	S7,			/* _+#.#e+#	#S7 */
 77 91c13e54 2004-02-29 devnull };
 78 91c13e54 2004-02-29 devnull 
 79 91c13e54 2004-02-29 devnull static	int	xcmp(char*, char*);
 80 91c13e54 2004-02-29 devnull static	int	fpcmp(char*, ulong*);
 81 91c13e54 2004-02-29 devnull static	void	frnorm(ulong*);
 82 91c13e54 2004-02-29 devnull static	void	divascii(char*, int*, int*, int*);
 83 91c13e54 2004-02-29 devnull static	void	mulascii(char*, int*, int*, int*);
 84 91c13e54 2004-02-29 devnull 
 85 91c13e54 2004-02-29 devnull typedef	struct	Tab	Tab;
 86 91c13e54 2004-02-29 devnull struct	Tab
 87 91c13e54 2004-02-29 devnull {
 88 91c13e54 2004-02-29 devnull 	int	bp;
 89 91c13e54 2004-02-29 devnull 	int	siz;
 90 91c13e54 2004-02-29 devnull 	char*	cmp;
 91 91c13e54 2004-02-29 devnull };
 92 91c13e54 2004-02-29 devnull 
 93 91c13e54 2004-02-29 devnull double
 94 91c13e54 2004-02-29 devnull fmtstrtod(const char *as, char **aas)
 95 91c13e54 2004-02-29 devnull {
 96 91c13e54 2004-02-29 devnull 	int na, ex, dp, bp, c, i, flag, state;
 97 91c13e54 2004-02-29 devnull 	ulong low[Prec], hig[Prec], mid[Prec];
 98 91c13e54 2004-02-29 devnull 	double d;
 99 91c13e54 2004-02-29 devnull 	char *s, a[Ndig];
100 91c13e54 2004-02-29 devnull 
101 91c13e54 2004-02-29 devnull 	flag = 0;	/* Fsign, Fesign, Fdpoint */
102 91c13e54 2004-02-29 devnull 	na = 0;		/* number of digits of a[] */
103 91c13e54 2004-02-29 devnull 	dp = 0;		/* na of decimal point */
104 91c13e54 2004-02-29 devnull 	ex = 0;		/* exonent */
105 91c13e54 2004-02-29 devnull 
106 91c13e54 2004-02-29 devnull 	state = S0;
107 91c13e54 2004-02-29 devnull 	for(s=(char*)as;; s++) {
108 91c13e54 2004-02-29 devnull 		c = *s;
109 91c13e54 2004-02-29 devnull 		if(c >= '0' && c <= '9') {
110 91c13e54 2004-02-29 devnull 			switch(state) {
111 91c13e54 2004-02-29 devnull 			case S0:
112 91c13e54 2004-02-29 devnull 			case S1:
113 91c13e54 2004-02-29 devnull 			case S2:
114 91c13e54 2004-02-29 devnull 				state = S2;
115 91c13e54 2004-02-29 devnull 				break;
116 91c13e54 2004-02-29 devnull 			case S3:
117 91c13e54 2004-02-29 devnull 			case S4:
118 91c13e54 2004-02-29 devnull 				state = S4;
119 91c13e54 2004-02-29 devnull 				break;
120 91c13e54 2004-02-29 devnull 
121 91c13e54 2004-02-29 devnull 			case S5:
122 91c13e54 2004-02-29 devnull 			case S6:
123 91c13e54 2004-02-29 devnull 			case S7:
124 91c13e54 2004-02-29 devnull 				state = S7;
125 91c13e54 2004-02-29 devnull 				ex = ex*10 + (c-'0');
126 91c13e54 2004-02-29 devnull 				continue;
127 91c13e54 2004-02-29 devnull 			}
128 91c13e54 2004-02-29 devnull 			if(na == 0 && c == '0') {
129 91c13e54 2004-02-29 devnull 				dp--;
130 91c13e54 2004-02-29 devnull 				continue;
131 91c13e54 2004-02-29 devnull 			}
132 91c13e54 2004-02-29 devnull 			if(na < Ndig-50)
133 91c13e54 2004-02-29 devnull 				a[na++] = c;
134 91c13e54 2004-02-29 devnull 			continue;
135 91c13e54 2004-02-29 devnull 		}
136 91c13e54 2004-02-29 devnull 		switch(c) {
137 91c13e54 2004-02-29 devnull 		case '\t':
138 91c13e54 2004-02-29 devnull 		case '\n':
139 91c13e54 2004-02-29 devnull 		case '\v':
140 91c13e54 2004-02-29 devnull 		case '\f':
141 91c13e54 2004-02-29 devnull 		case '\r':
142 91c13e54 2004-02-29 devnull 		case ' ':
143 91c13e54 2004-02-29 devnull 			if(state == S0)
144 91c13e54 2004-02-29 devnull 				continue;
145 91c13e54 2004-02-29 devnull 			break;
146 91c13e54 2004-02-29 devnull 		case '-':
147 91c13e54 2004-02-29 devnull 			if(state == S0)
148 91c13e54 2004-02-29 devnull 				flag |= Fsign;
149 91c13e54 2004-02-29 devnull 			else
150 91c13e54 2004-02-29 devnull 				flag |= Fesign;
151 91c13e54 2004-02-29 devnull 		case '+':
152 91c13e54 2004-02-29 devnull 			if(state == S0)
153 91c13e54 2004-02-29 devnull 				state = S1;
154 91c13e54 2004-02-29 devnull 			else
155 91c13e54 2004-02-29 devnull 			if(state == S5)
156 91c13e54 2004-02-29 devnull 				state = S6;
157 91c13e54 2004-02-29 devnull 			else
158 91c13e54 2004-02-29 devnull 				break;	/* syntax */
159 91c13e54 2004-02-29 devnull 			continue;
160 91c13e54 2004-02-29 devnull 		case '.':
161 91c13e54 2004-02-29 devnull 			flag |= Fdpoint;
162 91c13e54 2004-02-29 devnull 			dp = na;
163 91c13e54 2004-02-29 devnull 			if(state == S0 || state == S1) {
164 91c13e54 2004-02-29 devnull 				state = S3;
165 91c13e54 2004-02-29 devnull 				continue;
166 91c13e54 2004-02-29 devnull 			}
167 91c13e54 2004-02-29 devnull 			if(state == S2) {
168 91c13e54 2004-02-29 devnull 				state = S4;
169 91c13e54 2004-02-29 devnull 				continue;
170 91c13e54 2004-02-29 devnull 			}
171 91c13e54 2004-02-29 devnull 			break;
172 91c13e54 2004-02-29 devnull 		case 'e':
173 91c13e54 2004-02-29 devnull 		case 'E':
174 91c13e54 2004-02-29 devnull 			if(state == S2 || state == S4) {
175 91c13e54 2004-02-29 devnull 				state = S5;
176 91c13e54 2004-02-29 devnull 				continue;
177 91c13e54 2004-02-29 devnull 			}
178 91c13e54 2004-02-29 devnull 			break;
179 91c13e54 2004-02-29 devnull 		}
180 91c13e54 2004-02-29 devnull 		break;
181 91c13e54 2004-02-29 devnull 	}
182 91c13e54 2004-02-29 devnull 
183 91c13e54 2004-02-29 devnull 	/*
184 91c13e54 2004-02-29 devnull 	 * clean up return char-pointer
185 91c13e54 2004-02-29 devnull 	 */
186 91c13e54 2004-02-29 devnull 	switch(state) {
187 91c13e54 2004-02-29 devnull 	case S0:
188 91c13e54 2004-02-29 devnull 		if(xcmp(s, "nan") == 0) {
189 91c13e54 2004-02-29 devnull 			if(aas != nil)
190 91c13e54 2004-02-29 devnull 				*aas = s+3;
191 91c13e54 2004-02-29 devnull 			goto retnan;
192 91c13e54 2004-02-29 devnull 		}
193 91c13e54 2004-02-29 devnull 	case S1:
194 91c13e54 2004-02-29 devnull 		if(xcmp(s, "infinity") == 0) {
195 91c13e54 2004-02-29 devnull 			if(aas != nil)
196 91c13e54 2004-02-29 devnull 				*aas = s+8;
197 91c13e54 2004-02-29 devnull 			goto retinf;
198 91c13e54 2004-02-29 devnull 		}
199 91c13e54 2004-02-29 devnull 		if(xcmp(s, "inf") == 0) {
200 91c13e54 2004-02-29 devnull 			if(aas != nil)
201 91c13e54 2004-02-29 devnull 				*aas = s+3;
202 91c13e54 2004-02-29 devnull 			goto retinf;
203 91c13e54 2004-02-29 devnull 		}
204 91c13e54 2004-02-29 devnull 	case S3:
205 91c13e54 2004-02-29 devnull 		if(aas != nil)
206 91c13e54 2004-02-29 devnull 			*aas = (char*)as;
207 91c13e54 2004-02-29 devnull 		goto ret0;	/* no digits found */
208 91c13e54 2004-02-29 devnull 	case S6:
209 91c13e54 2004-02-29 devnull 		s--;		/* back over +- */
210 91c13e54 2004-02-29 devnull 	case S5:
211 91c13e54 2004-02-29 devnull 		s--;		/* back over e */
212 91c13e54 2004-02-29 devnull 		break;
213 91c13e54 2004-02-29 devnull 	}
214 91c13e54 2004-02-29 devnull 	if(aas != nil)
215 91c13e54 2004-02-29 devnull 		*aas = s;
216 91c13e54 2004-02-29 devnull 
217 91c13e54 2004-02-29 devnull 	if(flag & Fdpoint)
218 91c13e54 2004-02-29 devnull 	while(na > 0 && a[na-1] == '0')
219 91c13e54 2004-02-29 devnull 		na--;
220 91c13e54 2004-02-29 devnull 	if(na == 0)
221 91c13e54 2004-02-29 devnull 		goto ret0;	/* zero */
222 91c13e54 2004-02-29 devnull 	a[na] = 0;
223 91c13e54 2004-02-29 devnull 	if(!(flag & Fdpoint))
224 91c13e54 2004-02-29 devnull 		dp = na;
225 91c13e54 2004-02-29 devnull 	if(flag & Fesign)
226 91c13e54 2004-02-29 devnull 		ex = -ex;
227 91c13e54 2004-02-29 devnull 	dp += ex;
228 91c13e54 2004-02-29 devnull 	if(dp < -Maxe){
229 91c13e54 2004-02-29 devnull 		errno = ERANGE;
230 91c13e54 2004-02-29 devnull 		goto ret0;	/* underflow by exp */
231 91c13e54 2004-02-29 devnull 	} else
232 91c13e54 2004-02-29 devnull 	if(dp > +Maxe)
233 91c13e54 2004-02-29 devnull 		goto retinf;	/* overflow by exp */
234 91c13e54 2004-02-29 devnull 
235 91c13e54 2004-02-29 devnull 	/*
236 91c13e54 2004-02-29 devnull 	 * normalize the decimal ascii number
237 91c13e54 2004-02-29 devnull 	 * to range .[5-9][0-9]* e0
238 91c13e54 2004-02-29 devnull 	 */
239 91c13e54 2004-02-29 devnull 	bp = 0;		/* binary exponent */
240 91c13e54 2004-02-29 devnull 	while(dp > 0)
241 91c13e54 2004-02-29 devnull 		divascii(a, &na, &dp, &bp);
242 91c13e54 2004-02-29 devnull 	while(dp < 0 || a[0] < '5')
243 91c13e54 2004-02-29 devnull 		mulascii(a, &na, &dp, &bp);
244 91c13e54 2004-02-29 devnull 
245 91c13e54 2004-02-29 devnull 	/* close approx by naive conversion */
246 91c13e54 2004-02-29 devnull 	mid[0] = 0;
247 91c13e54 2004-02-29 devnull 	mid[1] = 1;
248 91c13e54 2004-02-29 devnull 	for(i=0; c=a[i]; i++) {
249 91c13e54 2004-02-29 devnull 		mid[0] = mid[0]*10 + (c-'0');
250 91c13e54 2004-02-29 devnull 		mid[1] = mid[1]*10;
251 91c13e54 2004-02-29 devnull 		if(i >= 8)
252 91c13e54 2004-02-29 devnull 			break;
253 91c13e54 2004-02-29 devnull 	}
254 91c13e54 2004-02-29 devnull 	low[0] = umuldiv(mid[0], One, mid[1]);
255 91c13e54 2004-02-29 devnull 	hig[0] = umuldiv(mid[0]+1, One, mid[1]);
256 91c13e54 2004-02-29 devnull 	for(i=1; i<Prec; i++) {
257 91c13e54 2004-02-29 devnull 		low[i] = 0;
258 91c13e54 2004-02-29 devnull 		hig[i] = One-1;
259 91c13e54 2004-02-29 devnull 	}
260 91c13e54 2004-02-29 devnull 
261 91c13e54 2004-02-29 devnull 	/* binary search for closest mantissa */
262 91c13e54 2004-02-29 devnull 	for(;;) {
263 91c13e54 2004-02-29 devnull 		/* mid = (hig + low) / 2 */
264 91c13e54 2004-02-29 devnull 		c = 0;
265 91c13e54 2004-02-29 devnull 		for(i=0; i<Prec; i++) {
266 91c13e54 2004-02-29 devnull 			mid[i] = hig[i] + low[i];
267 91c13e54 2004-02-29 devnull 			if(c)
268 91c13e54 2004-02-29 devnull 				mid[i] += One;
269 91c13e54 2004-02-29 devnull 			c = mid[i] & 1;
270 91c13e54 2004-02-29 devnull 			mid[i] >>= 1;
271 91c13e54 2004-02-29 devnull 		}
272 91c13e54 2004-02-29 devnull 		frnorm(mid);
273 91c13e54 2004-02-29 devnull 
274 91c13e54 2004-02-29 devnull 		/* compare */
275 91c13e54 2004-02-29 devnull 		c = fpcmp(a, mid);
276 91c13e54 2004-02-29 devnull 		if(c > 0) {
277 91c13e54 2004-02-29 devnull 			c = 1;
278 91c13e54 2004-02-29 devnull 			for(i=0; i<Prec; i++)
279 91c13e54 2004-02-29 devnull 				if(low[i] != mid[i]) {
280 91c13e54 2004-02-29 devnull 					c = 0;
281 91c13e54 2004-02-29 devnull 					low[i] = mid[i];
282 91c13e54 2004-02-29 devnull 				}
283 91c13e54 2004-02-29 devnull 			if(c)
284 91c13e54 2004-02-29 devnull 				break;	/* between mid and hig */
285 91c13e54 2004-02-29 devnull 			continue;
286 91c13e54 2004-02-29 devnull 		}
287 91c13e54 2004-02-29 devnull 		if(c < 0) {
288 91c13e54 2004-02-29 devnull 			for(i=0; i<Prec; i++)
289 91c13e54 2004-02-29 devnull 				hig[i] = mid[i];
290 91c13e54 2004-02-29 devnull 			continue;
291 91c13e54 2004-02-29 devnull 		}
292 91c13e54 2004-02-29 devnull 
293 91c13e54 2004-02-29 devnull 		/* only hard part is if even/odd roundings wants to go up */
294 91c13e54 2004-02-29 devnull 		c = mid[Prec-1] & (Sigbit-1);
295 91c13e54 2004-02-29 devnull 		if(c == Sigbit/2 && (mid[Prec-1]&Sigbit) == 0)
296 91c13e54 2004-02-29 devnull 			mid[Prec-1] -= c;
297 91c13e54 2004-02-29 devnull 		break;	/* exactly mid */
298 91c13e54 2004-02-29 devnull 	}
299 91c13e54 2004-02-29 devnull 
300 91c13e54 2004-02-29 devnull 	/* normal rounding applies */
301 91c13e54 2004-02-29 devnull 	c = mid[Prec-1] & (Sigbit-1);
302 91c13e54 2004-02-29 devnull 	mid[Prec-1] -= c;
303 91c13e54 2004-02-29 devnull 	if(c >= Sigbit/2) {
304 91c13e54 2004-02-29 devnull 		mid[Prec-1] += Sigbit;
305 91c13e54 2004-02-29 devnull 		frnorm(mid);
306 91c13e54 2004-02-29 devnull 	}
307 91c13e54 2004-02-29 devnull 	goto out;
308 91c13e54 2004-02-29 devnull 
309 91c13e54 2004-02-29 devnull ret0:
310 91c13e54 2004-02-29 devnull 	return 0;
311 91c13e54 2004-02-29 devnull 
312 91c13e54 2004-02-29 devnull retnan:
313 91c13e54 2004-02-29 devnull 	return __NaN();
314 91c13e54 2004-02-29 devnull 
315 91c13e54 2004-02-29 devnull retinf:
316 91c13e54 2004-02-29 devnull 	/*
317 91c13e54 2004-02-29 devnull 	 * Unix strtod requires these.  Plan 9 would return Inf(0) or Inf(-1). */
318 91c13e54 2004-02-29 devnull 	errno = ERANGE;
319 91c13e54 2004-02-29 devnull 	if(flag & Fsign)
320 91c13e54 2004-02-29 devnull 		return -HUGE_VAL;
321 91c13e54 2004-02-29 devnull 	return HUGE_VAL;
322 91c13e54 2004-02-29 devnull 
323 91c13e54 2004-02-29 devnull out:
324 91c13e54 2004-02-29 devnull 	d = 0;
325 91c13e54 2004-02-29 devnull 	for(i=0; i<Prec; i++)
326 91c13e54 2004-02-29 devnull 		d = d*One + mid[i];
327 91c13e54 2004-02-29 devnull 	if(flag & Fsign)
328 91c13e54 2004-02-29 devnull 		d = -d;
329 91c13e54 2004-02-29 devnull 	d = ldexp(d, bp - Prec*Nbits);
330 91c13e54 2004-02-29 devnull 	if(d == 0){	/* underflow */
331 91c13e54 2004-02-29 devnull 		errno = ERANGE;
332 91c13e54 2004-02-29 devnull 	}
333 91c13e54 2004-02-29 devnull 	return d;
334 91c13e54 2004-02-29 devnull }
335 91c13e54 2004-02-29 devnull 
336 91c13e54 2004-02-29 devnull static void
337 91c13e54 2004-02-29 devnull frnorm(ulong *f)
338 91c13e54 2004-02-29 devnull {
339 91c13e54 2004-02-29 devnull 	int i, c;
340 91c13e54 2004-02-29 devnull 
341 91c13e54 2004-02-29 devnull 	c = 0;
342 91c13e54 2004-02-29 devnull 	for(i=Prec-1; i>0; i--) {
343 91c13e54 2004-02-29 devnull 		f[i] += c;
344 91c13e54 2004-02-29 devnull 		c = f[i] >> Nbits;
345 91c13e54 2004-02-29 devnull 		f[i] &= One-1;
346 91c13e54 2004-02-29 devnull 	}
347 91c13e54 2004-02-29 devnull 	f[0] += c;
348 91c13e54 2004-02-29 devnull }
349 91c13e54 2004-02-29 devnull 
350 91c13e54 2004-02-29 devnull static int
351 91c13e54 2004-02-29 devnull fpcmp(char *a, ulong* f)
352 91c13e54 2004-02-29 devnull {
353 91c13e54 2004-02-29 devnull 	ulong tf[Prec];
354 91c13e54 2004-02-29 devnull 	int i, d, c;
355 91c13e54 2004-02-29 devnull 
356 91c13e54 2004-02-29 devnull 	for(i=0; i<Prec; i++)
357 91c13e54 2004-02-29 devnull 		tf[i] = f[i];
358 91c13e54 2004-02-29 devnull 
359 91c13e54 2004-02-29 devnull 	for(;;) {
360 91c13e54 2004-02-29 devnull 		/* tf *= 10 */
361 91c13e54 2004-02-29 devnull 		for(i=0; i<Prec; i++)
362 91c13e54 2004-02-29 devnull 			tf[i] = tf[i]*10;
363 91c13e54 2004-02-29 devnull 		frnorm(tf);
364 91c13e54 2004-02-29 devnull 		d = (tf[0] >> Nbits) + '0';
365 91c13e54 2004-02-29 devnull 		tf[0] &= One-1;
366 91c13e54 2004-02-29 devnull 
367 91c13e54 2004-02-29 devnull 		/* compare next digit */
368 91c13e54 2004-02-29 devnull 		c = *a;
369 91c13e54 2004-02-29 devnull 		if(c == 0) {
370 91c13e54 2004-02-29 devnull 			if('0' < d)
371 91c13e54 2004-02-29 devnull 				return -1;
372 91c13e54 2004-02-29 devnull 			if(tf[0] != 0)
373 91c13e54 2004-02-29 devnull 				goto cont;
374 91c13e54 2004-02-29 devnull 			for(i=1; i<Prec; i++)
375 91c13e54 2004-02-29 devnull 				if(tf[i] != 0)
376 91c13e54 2004-02-29 devnull 					goto cont;
377 91c13e54 2004-02-29 devnull 			return 0;
378 91c13e54 2004-02-29 devnull 		}
379 91c13e54 2004-02-29 devnull 		if(c > d)
380 91c13e54 2004-02-29 devnull 			return +1;
381 91c13e54 2004-02-29 devnull 		if(c < d)
382 91c13e54 2004-02-29 devnull 			return -1;
383 91c13e54 2004-02-29 devnull 		a++;
384 91c13e54 2004-02-29 devnull 	cont:;
385 91c13e54 2004-02-29 devnull 	}
386 91c13e54 2004-02-29 devnull 	return 0;
387 91c13e54 2004-02-29 devnull }
388 91c13e54 2004-02-29 devnull 
389 91c13e54 2004-02-29 devnull static void
390 91c13e54 2004-02-29 devnull divby(char *a, int *na, int b)
391 91c13e54 2004-02-29 devnull {
392 91c13e54 2004-02-29 devnull 	int n, c;
393 91c13e54 2004-02-29 devnull 	char *p;
394 91c13e54 2004-02-29 devnull 
395 91c13e54 2004-02-29 devnull 	p = a;
396 91c13e54 2004-02-29 devnull 	n = 0;
397 91c13e54 2004-02-29 devnull 	while(n>>b == 0) {
398 91c13e54 2004-02-29 devnull 		c = *a++;
399 91c13e54 2004-02-29 devnull 		if(c == 0) {
400 91c13e54 2004-02-29 devnull 			while(n) {
401 91c13e54 2004-02-29 devnull 				c = n*10;
402 91c13e54 2004-02-29 devnull 				if(c>>b)
403 91c13e54 2004-02-29 devnull 					break;
404 91c13e54 2004-02-29 devnull 				n = c;
405 91c13e54 2004-02-29 devnull 			}
406 91c13e54 2004-02-29 devnull 			goto xx;
407 91c13e54 2004-02-29 devnull 		}
408 91c13e54 2004-02-29 devnull 		n = n*10 + c-'0';
409 91c13e54 2004-02-29 devnull 		(*na)--;
410 91c13e54 2004-02-29 devnull 	}
411 91c13e54 2004-02-29 devnull 	for(;;) {
412 91c13e54 2004-02-29 devnull 		c = n>>b;
413 91c13e54 2004-02-29 devnull 		n -= c<<b;
414 91c13e54 2004-02-29 devnull 		*p++ = c + '0';
415 91c13e54 2004-02-29 devnull 		c = *a++;
416 91c13e54 2004-02-29 devnull 		if(c == 0)
417 91c13e54 2004-02-29 devnull 			break;
418 91c13e54 2004-02-29 devnull 		n = n*10 + c-'0';
419 91c13e54 2004-02-29 devnull 	}
420 91c13e54 2004-02-29 devnull 	(*na)++;
421 91c13e54 2004-02-29 devnull xx:
422 91c13e54 2004-02-29 devnull 	while(n) {
423 91c13e54 2004-02-29 devnull 		n = n*10;
424 91c13e54 2004-02-29 devnull 		c = n>>b;
425 91c13e54 2004-02-29 devnull 		n -= c<<b;
426 91c13e54 2004-02-29 devnull 		*p++ = c + '0';
427 91c13e54 2004-02-29 devnull 		(*na)++;
428 91c13e54 2004-02-29 devnull 	}
429 91c13e54 2004-02-29 devnull 	*p = 0;
430 91c13e54 2004-02-29 devnull }
431 91c13e54 2004-02-29 devnull 
432 91c13e54 2004-02-29 devnull static	Tab	tab1[] =
433 91c13e54 2004-02-29 devnull {
434 91c13e54 2004-02-29 devnull 	 1,  0, "",
435 91c13e54 2004-02-29 devnull 	 3,  1, "7",
436 91c13e54 2004-02-29 devnull 	 6,  2, "63",
437 91c13e54 2004-02-29 devnull 	 9,  3, "511",
438 91c13e54 2004-02-29 devnull 	13,  4, "8191",
439 91c13e54 2004-02-29 devnull 	16,  5, "65535",
440 91c13e54 2004-02-29 devnull 	19,  6, "524287",
441 91c13e54 2004-02-29 devnull 	23,  7, "8388607",
442 91c13e54 2004-02-29 devnull 	26,  8, "67108863",
443 91c13e54 2004-02-29 devnull 	27,  9, "134217727",
444 91c13e54 2004-02-29 devnull };
445 91c13e54 2004-02-29 devnull 
446 91c13e54 2004-02-29 devnull static void
447 91c13e54 2004-02-29 devnull divascii(char *a, int *na, int *dp, int *bp)
448 91c13e54 2004-02-29 devnull {
449 91c13e54 2004-02-29 devnull 	int b, d;
450 91c13e54 2004-02-29 devnull 	Tab *t;
451 91c13e54 2004-02-29 devnull 
452 91c13e54 2004-02-29 devnull 	d = *dp;
453 91c13e54 2004-02-29 devnull 	if(d >= (int)(nelem(tab1)))
454 91c13e54 2004-02-29 devnull 		d = (int)(nelem(tab1))-1;
455 91c13e54 2004-02-29 devnull 	t = tab1 + d;
456 91c13e54 2004-02-29 devnull 	b = t->bp;
457 91c13e54 2004-02-29 devnull 	if(memcmp(a, t->cmp, t->siz) > 0)
458 91c13e54 2004-02-29 devnull 		d--;
459 91c13e54 2004-02-29 devnull 	*dp -= d;
460 91c13e54 2004-02-29 devnull 	*bp += b;
461 91c13e54 2004-02-29 devnull 	divby(a, na, b);
462 91c13e54 2004-02-29 devnull }
463 91c13e54 2004-02-29 devnull 
464 91c13e54 2004-02-29 devnull static void
465 91c13e54 2004-02-29 devnull mulby(char *a, char *p, char *q, int b)
466 91c13e54 2004-02-29 devnull {
467 91c13e54 2004-02-29 devnull 	int n, c;
468 91c13e54 2004-02-29 devnull 
469 91c13e54 2004-02-29 devnull 	n = 0;
470 91c13e54 2004-02-29 devnull 	*p = 0;
471 91c13e54 2004-02-29 devnull 	for(;;) {
472 91c13e54 2004-02-29 devnull 		q--;
473 91c13e54 2004-02-29 devnull 		if(q < a)
474 91c13e54 2004-02-29 devnull 			break;
475 91c13e54 2004-02-29 devnull 		c = *q - '0';
476 91c13e54 2004-02-29 devnull 		c = (c<<b) + n;
477 91c13e54 2004-02-29 devnull 		n = c/10;
478 91c13e54 2004-02-29 devnull 		c -= n*10;
479 91c13e54 2004-02-29 devnull 		p--;
480 91c13e54 2004-02-29 devnull 		*p = c + '0';
481 91c13e54 2004-02-29 devnull 	}
482 91c13e54 2004-02-29 devnull 	while(n) {
483 91c13e54 2004-02-29 devnull 		c = n;
484 91c13e54 2004-02-29 devnull 		n = c/10;
485 91c13e54 2004-02-29 devnull 		c -= n*10;
486 91c13e54 2004-02-29 devnull 		p--;
487 91c13e54 2004-02-29 devnull 		*p = c + '0';
488 91c13e54 2004-02-29 devnull 	}
489 91c13e54 2004-02-29 devnull }
490 91c13e54 2004-02-29 devnull 
491 91c13e54 2004-02-29 devnull static	Tab	tab2[] =
492 91c13e54 2004-02-29 devnull {
493 91c13e54 2004-02-29 devnull 	 1,  1, "",				/* dp = 0-0 */
494 91c13e54 2004-02-29 devnull 	 3,  3, "125",
495 91c13e54 2004-02-29 devnull 	 6,  5, "15625",
496 91c13e54 2004-02-29 devnull 	 9,  7, "1953125",
497 91c13e54 2004-02-29 devnull 	13, 10, "1220703125",
498 91c13e54 2004-02-29 devnull 	16, 12, "152587890625",
499 91c13e54 2004-02-29 devnull 	19, 14, "19073486328125",
500 91c13e54 2004-02-29 devnull 	23, 17, "11920928955078125",
501 91c13e54 2004-02-29 devnull 	26, 19, "1490116119384765625",
502 91c13e54 2004-02-29 devnull 	27, 19, "7450580596923828125",		/* dp 8-9 */
503 91c13e54 2004-02-29 devnull };
504 91c13e54 2004-02-29 devnull 
505 91c13e54 2004-02-29 devnull static void
506 91c13e54 2004-02-29 devnull mulascii(char *a, int *na, int *dp, int *bp)
507 91c13e54 2004-02-29 devnull {
508 91c13e54 2004-02-29 devnull 	char *p;
509 91c13e54 2004-02-29 devnull 	int d, b;
510 91c13e54 2004-02-29 devnull 	Tab *t;
511 91c13e54 2004-02-29 devnull 
512 91c13e54 2004-02-29 devnull 	d = -*dp;
513 91c13e54 2004-02-29 devnull 	if(d >= (int)(nelem(tab2)))
514 91c13e54 2004-02-29 devnull 		d = (int)(nelem(tab2))-1;
515 91c13e54 2004-02-29 devnull 	t = tab2 + d;
516 91c13e54 2004-02-29 devnull 	b = t->bp;
517 91c13e54 2004-02-29 devnull 	if(memcmp(a, t->cmp, t->siz) < 0)
518 91c13e54 2004-02-29 devnull 		d--;
519 91c13e54 2004-02-29 devnull 	p = a + *na;
520 91c13e54 2004-02-29 devnull 	*bp -= b;
521 91c13e54 2004-02-29 devnull 	*dp += d;
522 91c13e54 2004-02-29 devnull 	*na += d;
523 91c13e54 2004-02-29 devnull 	mulby(a, p+d, p, b);
524 91c13e54 2004-02-29 devnull }
525 91c13e54 2004-02-29 devnull 
526 91c13e54 2004-02-29 devnull static int
527 91c13e54 2004-02-29 devnull xcmp(char *a, char *b)
528 91c13e54 2004-02-29 devnull {
529 91c13e54 2004-02-29 devnull 	int c1, c2;
530 91c13e54 2004-02-29 devnull 
531 91c13e54 2004-02-29 devnull 	while(c1 = *b++) {
532 91c13e54 2004-02-29 devnull 		c2 = *a++;
533 91c13e54 2004-02-29 devnull 		if(isupper(c2))
534 91c13e54 2004-02-29 devnull 			c2 = tolower(c2);
535 91c13e54 2004-02-29 devnull 		if(c1 != c2)
536 91c13e54 2004-02-29 devnull 			return 1;
537 91c13e54 2004-02-29 devnull 	}
538 91c13e54 2004-02-29 devnull 	return 0;
539 91c13e54 2004-02-29 devnull }