1 85231fd8 2006-05-21 devnull /* Copyright (c) 2002-2006 Lucent Technologies; see LICENSE */
  2 91c13e54 2004-02-29 devnull #include <stdio.h>
  3 91c13e54 2004-02-29 devnull #include <math.h>
  4 91c13e54 2004-02-29 devnull #include <float.h>
  5 91c13e54 2004-02-29 devnull #include <string.h>
  6 91c13e54 2004-02-29 devnull #include <stdlib.h>
  7 91c13e54 2004-02-29 devnull #include <errno.h>
  8 91c13e54 2004-02-29 devnull #include <stdarg.h>
  9 e5aa96ac 2004-12-26 devnull #include <fmt.h>
 10 f8955f18 2006-05-22 devnull #include <assert.h>
 11 e5aa96ac 2004-12-26 devnull #include "plan9.h"
 12 91c13e54 2004-02-29 devnull #include "fmt.h"
 13 91c13e54 2004-02-29 devnull #include "fmtdef.h"
 14 f8955f18 2006-05-22 devnull #include "nan.h"
 15 91c13e54 2004-02-29 devnull 
 16 91c13e54 2004-02-29 devnull enum
 17 91c13e54 2004-02-29 devnull {
 18 a76c0fd4 2004-12-26 devnull 	FDIGIT	= 30,
 19 91c13e54 2004-02-29 devnull 	FDEFLT	= 6,
 20 91c13e54 2004-02-29 devnull 	NSIGNIF	= 17
 21 91c13e54 2004-02-29 devnull };
 22 91c13e54 2004-02-29 devnull 
 23 91c13e54 2004-02-29 devnull /*
 24 91c13e54 2004-02-29 devnull  * first few powers of 10, enough for about 1/2 of the
 25 91c13e54 2004-02-29 devnull  * total space for doubles.
 26 91c13e54 2004-02-29 devnull  */
 27 91c13e54 2004-02-29 devnull static double pows10[] =
 28 91c13e54 2004-02-29 devnull {
 29 91c13e54 2004-02-29 devnull 	  1e0,   1e1,   1e2,   1e3,   1e4,   1e5,   1e6,   1e7,   1e8,   1e9,  
 30 91c13e54 2004-02-29 devnull 	 1e10,  1e11,  1e12,  1e13,  1e14,  1e15,  1e16,  1e17,  1e18,  1e19,  
 31 91c13e54 2004-02-29 devnull 	 1e20,  1e21,  1e22,  1e23,  1e24,  1e25,  1e26,  1e27,  1e28,  1e29,  
 32 91c13e54 2004-02-29 devnull 	 1e30,  1e31,  1e32,  1e33,  1e34,  1e35,  1e36,  1e37,  1e38,  1e39,  
 33 91c13e54 2004-02-29 devnull 	 1e40,  1e41,  1e42,  1e43,  1e44,  1e45,  1e46,  1e47,  1e48,  1e49,  
 34 91c13e54 2004-02-29 devnull 	 1e50,  1e51,  1e52,  1e53,  1e54,  1e55,  1e56,  1e57,  1e58,  1e59,  
 35 91c13e54 2004-02-29 devnull 	 1e60,  1e61,  1e62,  1e63,  1e64,  1e65,  1e66,  1e67,  1e68,  1e69,  
 36 91c13e54 2004-02-29 devnull 	 1e70,  1e71,  1e72,  1e73,  1e74,  1e75,  1e76,  1e77,  1e78,  1e79,  
 37 91c13e54 2004-02-29 devnull 	 1e80,  1e81,  1e82,  1e83,  1e84,  1e85,  1e86,  1e87,  1e88,  1e89,  
 38 91c13e54 2004-02-29 devnull 	 1e90,  1e91,  1e92,  1e93,  1e94,  1e95,  1e96,  1e97,  1e98,  1e99,  
 39 91c13e54 2004-02-29 devnull 	1e100, 1e101, 1e102, 1e103, 1e104, 1e105, 1e106, 1e107, 1e108, 1e109, 
 40 91c13e54 2004-02-29 devnull 	1e110, 1e111, 1e112, 1e113, 1e114, 1e115, 1e116, 1e117, 1e118, 1e119, 
 41 91c13e54 2004-02-29 devnull 	1e120, 1e121, 1e122, 1e123, 1e124, 1e125, 1e126, 1e127, 1e128, 1e129, 
 42 91c13e54 2004-02-29 devnull 	1e130, 1e131, 1e132, 1e133, 1e134, 1e135, 1e136, 1e137, 1e138, 1e139, 
 43 91c13e54 2004-02-29 devnull 	1e140, 1e141, 1e142, 1e143, 1e144, 1e145, 1e146, 1e147, 1e148, 1e149, 
 44 91c13e54 2004-02-29 devnull 	1e150, 1e151, 1e152, 1e153, 1e154, 1e155, 1e156, 1e157, 1e158, 1e159, 
 45 91c13e54 2004-02-29 devnull };
 46 f8955f18 2006-05-22 devnull #define	npows10 ((int)(sizeof(pows10)/sizeof(pows10[0])))
 47 f8955f18 2006-05-22 devnull #define	pow10(x)  fmtpow10(x)
 48 4645c5d7 2004-12-29 devnull 
 49 91c13e54 2004-02-29 devnull static double
 50 91c13e54 2004-02-29 devnull pow10(int n)
 51 91c13e54 2004-02-29 devnull {
 52 91c13e54 2004-02-29 devnull 	double d;
 53 91c13e54 2004-02-29 devnull 	int neg;
 54 91c13e54 2004-02-29 devnull 
 55 91c13e54 2004-02-29 devnull 	neg = 0;
 56 91c13e54 2004-02-29 devnull 	if(n < 0){
 57 f8955f18 2006-05-22 devnull 		if(n < DBL_MIN_10_EXP)
 58 91c13e54 2004-02-29 devnull 			return 0.;
 59 91c13e54 2004-02-29 devnull 		neg = 1;
 60 91c13e54 2004-02-29 devnull 		n = -n;
 61 f8955f18 2006-05-22 devnull 	}else if(n > DBL_MAX_10_EXP)
 62 91c13e54 2004-02-29 devnull 		return HUGE_VAL;
 63 f8955f18 2006-05-22 devnull 
 64 f8955f18 2006-05-22 devnull 	if(n < npows10)
 65 91c13e54 2004-02-29 devnull 		d = pows10[n];
 66 91c13e54 2004-02-29 devnull 	else{
 67 f8955f18 2006-05-22 devnull 		d = pows10[npows10-1];
 68 91c13e54 2004-02-29 devnull 		for(;;){
 69 f8955f18 2006-05-22 devnull 			n -= npows10 - 1;
 70 f8955f18 2006-05-22 devnull 			if(n < npows10){
 71 91c13e54 2004-02-29 devnull 				d *= pows10[n];
 72 91c13e54 2004-02-29 devnull 				break;
 73 91c13e54 2004-02-29 devnull 			}
 74 f8955f18 2006-05-22 devnull 			d *= pows10[npows10 - 1];
 75 91c13e54 2004-02-29 devnull 		}
 76 91c13e54 2004-02-29 devnull 	}
 77 f8955f18 2006-05-22 devnull 	if(neg)
 78 91c13e54 2004-02-29 devnull 		return 1./d;
 79 91c13e54 2004-02-29 devnull 	return d;
 80 91c13e54 2004-02-29 devnull }
 81 91c13e54 2004-02-29 devnull 
 82 f8955f18 2006-05-22 devnull /*
 83 f8955f18 2006-05-22 devnull  * add 1 to the decimal integer string a of length n.
 84 f8955f18 2006-05-22 devnull  * if 99999 overflows into 10000, return 1 to tell caller
 85 f8955f18 2006-05-22 devnull  * to move the virtual decimal point.
 86 f8955f18 2006-05-22 devnull  */
 87 91c13e54 2004-02-29 devnull static int
 88 f8955f18 2006-05-22 devnull xadd1(char *a, int n)
 89 91c13e54 2004-02-29 devnull {
 90 91c13e54 2004-02-29 devnull 	char *b;
 91 91c13e54 2004-02-29 devnull 	int c;
 92 91c13e54 2004-02-29 devnull 
 93 f8955f18 2006-05-22 devnull 	if(n < 0 || n > NSIGNIF)
 94 91c13e54 2004-02-29 devnull 		return 0;
 95 f8955f18 2006-05-22 devnull 	for(b = a+n-1; b >= a; b--) {
 96 f8955f18 2006-05-22 devnull 		c = *b + 1;
 97 91c13e54 2004-02-29 devnull 		if(c <= '9') {
 98 91c13e54 2004-02-29 devnull 			*b = c;
 99 91c13e54 2004-02-29 devnull 			return 0;
100 91c13e54 2004-02-29 devnull 		}
101 91c13e54 2004-02-29 devnull 		*b = '0';
102 91c13e54 2004-02-29 devnull 	}
103 f8955f18 2006-05-22 devnull 	/*
104 f8955f18 2006-05-22 devnull 	 * need to overflow adding digit.
105 f8955f18 2006-05-22 devnull 	 * shift number down and insert 1 at beginning.
106 f8955f18 2006-05-22 devnull 	 * decimal is known to be 0s or we wouldn't
107 f8955f18 2006-05-22 devnull 	 * have gotten this far.  (e.g., 99999+1 => 00000)
108 f8955f18 2006-05-22 devnull 	 */
109 f8955f18 2006-05-22 devnull 	a[0] = '1';
110 91c13e54 2004-02-29 devnull 	return 1;
111 91c13e54 2004-02-29 devnull }
112 91c13e54 2004-02-29 devnull 
113 f8955f18 2006-05-22 devnull /*
114 f8955f18 2006-05-22 devnull  * subtract 1 from the decimal integer string a.
115 f8955f18 2006-05-22 devnull  * if 10000 underflows into 09999, make it 99999
116 f8955f18 2006-05-22 devnull  * and return 1 to tell caller to move the virtual 
117 f8955f18 2006-05-22 devnull  * decimal point.  this way, xsub1 is inverse of xadd1.
118 f8955f18 2006-05-22 devnull  */
119 91c13e54 2004-02-29 devnull static int
120 f8955f18 2006-05-22 devnull xsub1(char *a, int n)
121 91c13e54 2004-02-29 devnull {
122 91c13e54 2004-02-29 devnull 	char *b;
123 91c13e54 2004-02-29 devnull 	int c;
124 91c13e54 2004-02-29 devnull 
125 f8955f18 2006-05-22 devnull 	if(n < 0 || n > NSIGNIF)
126 f8955f18 2006-05-22 devnull 		return 0;
127 f8955f18 2006-05-22 devnull 	for(b = a+n-1; b >= a; b--) {
128 f8955f18 2006-05-22 devnull 		c = *b - 1;
129 91c13e54 2004-02-29 devnull 		if(c >= '0') {
130 f8955f18 2006-05-22 devnull 			if(c == '0' && b == a) {
131 f8955f18 2006-05-22 devnull 				/*
132 f8955f18 2006-05-22 devnull 				 * just zeroed the top digit; shift everyone up.
133 f8955f18 2006-05-22 devnull 				 * decimal is known to be 9s or we wouldn't
134 f8955f18 2006-05-22 devnull 				 * have gotten this far.  (e.g., 10000-1 => 09999)
135 f8955f18 2006-05-22 devnull 				 */
136 f8955f18 2006-05-22 devnull 				*b = '9';
137 f8955f18 2006-05-22 devnull 				return 1;
138 f8955f18 2006-05-22 devnull 			}
139 91c13e54 2004-02-29 devnull 			*b = c;
140 91c13e54 2004-02-29 devnull 			return 0;
141 91c13e54 2004-02-29 devnull 		}
142 91c13e54 2004-02-29 devnull 		*b = '9';
143 91c13e54 2004-02-29 devnull 	}
144 f8955f18 2006-05-22 devnull 	/*
145 f8955f18 2006-05-22 devnull 	 * can't get here.  the number a is always normalized
146 f8955f18 2006-05-22 devnull 	 * so that it has a nonzero first digit.
147 f8955f18 2006-05-22 devnull 	 */
148 f8955f18 2006-05-22 devnull 	abort();
149 91c13e54 2004-02-29 devnull }
150 91c13e54 2004-02-29 devnull 
151 f8955f18 2006-05-22 devnull /*
152 f8955f18 2006-05-22 devnull  * format exponent like sprintf(p, "e%+02d", e)
153 f8955f18 2006-05-22 devnull  */
154 91c13e54 2004-02-29 devnull static void
155 f8955f18 2006-05-22 devnull xfmtexp(char *p, int e, int ucase)
156 91c13e54 2004-02-29 devnull {
157 f8955f18 2006-05-22 devnull 	char se[9];
158 f8955f18 2006-05-22 devnull 	int i;
159 91c13e54 2004-02-29 devnull 
160 f8955f18 2006-05-22 devnull 	*p++ = ucase ? 'E' : 'e';
161 f8955f18 2006-05-22 devnull 	if(e < 0) {
162 f8955f18 2006-05-22 devnull 		*p++ = '-';
163 f8955f18 2006-05-22 devnull 		e = -e;
164 f8955f18 2006-05-22 devnull 	} else
165 f8955f18 2006-05-22 devnull 		*p++ = '+';
166 f8955f18 2006-05-22 devnull 	i = 0;
167 f8955f18 2006-05-22 devnull 	while(e) {
168 f8955f18 2006-05-22 devnull 		se[i++] = e % 10 + '0';
169 f8955f18 2006-05-22 devnull 		e /= 10;
170 91c13e54 2004-02-29 devnull 	}
171 f8955f18 2006-05-22 devnull 	while(i < 2)
172 f8955f18 2006-05-22 devnull 		se[i++] = '0';
173 f8955f18 2006-05-22 devnull 	while(i > 0)
174 f8955f18 2006-05-22 devnull 		*p++ = se[--i];
175 f8955f18 2006-05-22 devnull 	*p++ = '\0';
176 f8955f18 2006-05-22 devnull }
177 f8955f18 2006-05-22 devnull 
178 f8955f18 2006-05-22 devnull /*
179 f8955f18 2006-05-22 devnull  * compute decimal integer m, exp such that:
180 f8955f18 2006-05-22 devnull  *	f = m*10^exp
181 f8955f18 2006-05-22 devnull  *	m is as short as possible with losing exactness
182 f8955f18 2006-05-22 devnull  * assumes special cases (NaN, +Inf, -Inf) have been handled.
183 f8955f18 2006-05-22 devnull  */
184 f8955f18 2006-05-22 devnull static void
185 f8955f18 2006-05-22 devnull xdtoa(double f, char *s, int *exp, int *neg, int *ns)
186 f8955f18 2006-05-22 devnull {
187 f8955f18 2006-05-22 devnull 	int c, d, e2, e, ee, i, ndigit, oerrno;
188 f8955f18 2006-05-22 devnull 	char tmp[NSIGNIF+10];
189 f8955f18 2006-05-22 devnull 	double g;
190 f8955f18 2006-05-22 devnull 
191 f8955f18 2006-05-22 devnull 	oerrno = errno; /* in case strtod smashes errno */
192 f8955f18 2006-05-22 devnull 
193 f8955f18 2006-05-22 devnull 	/*
194 f8955f18 2006-05-22 devnull 	 * make f non-negative.
195 f8955f18 2006-05-22 devnull 	 */
196 f8955f18 2006-05-22 devnull 	*neg = 0;
197 91c13e54 2004-02-29 devnull 	if(f < 0) {
198 91c13e54 2004-02-29 devnull 		f = -f;
199 f8955f18 2006-05-22 devnull 		*neg = 1;
200 91c13e54 2004-02-29 devnull 	}
201 91c13e54 2004-02-29 devnull 
202 91c13e54 2004-02-29 devnull 	/*
203 f8955f18 2006-05-22 devnull 	 * must handle zero specially.
204 91c13e54 2004-02-29 devnull 	 */
205 f8955f18 2006-05-22 devnull 	if(f == 0){
206 f8955f18 2006-05-22 devnull 		*exp = 0;
207 f8955f18 2006-05-22 devnull 		s[0] = '0';
208 f8955f18 2006-05-22 devnull 		s[1] = '\0';
209 f8955f18 2006-05-22 devnull 		*ns = 1;
210 f8955f18 2006-05-22 devnull 		return;
211 91c13e54 2004-02-29 devnull 	}
212 f8955f18 2006-05-22 devnull 		
213 91c13e54 2004-02-29 devnull 	/*
214 f8955f18 2006-05-22 devnull 	 * find g,e such that f = g*10^e.
215 f8955f18 2006-05-22 devnull 	 * guess 10-exponent using 2-exponent, then fine tune.
216 91c13e54 2004-02-29 devnull 	 */
217 f8955f18 2006-05-22 devnull 	frexp(f, &e2);
218 f8955f18 2006-05-22 devnull 	e = (int)(e2 * .301029995664);
219 f8955f18 2006-05-22 devnull 	g = f * pow10(-e);
220 f8955f18 2006-05-22 devnull 	while(g < 1) {
221 f8955f18 2006-05-22 devnull 		e--;
222 f8955f18 2006-05-22 devnull 		g = f * pow10(-e);
223 91c13e54 2004-02-29 devnull 	}
224 f8955f18 2006-05-22 devnull 	while(g >= 10) {
225 f8955f18 2006-05-22 devnull 		e++;
226 f8955f18 2006-05-22 devnull 		g = f * pow10(-e);
227 f8955f18 2006-05-22 devnull 	}
228 91c13e54 2004-02-29 devnull 
229 91c13e54 2004-02-29 devnull 	/*
230 f8955f18 2006-05-22 devnull 	 * convert NSIGNIF digits as a first approximation.
231 91c13e54 2004-02-29 devnull 	 */
232 f8955f18 2006-05-22 devnull 	for(i=0; i<NSIGNIF; i++) {
233 f8955f18 2006-05-22 devnull 		d = (int)g;
234 f8955f18 2006-05-22 devnull 		s[i] = d+'0';
235 f8955f18 2006-05-22 devnull 		g = (g-d) * 10;
236 f8955f18 2006-05-22 devnull 	}
237 f8955f18 2006-05-22 devnull 	s[i] = 0;
238 f8955f18 2006-05-22 devnull 
239 f8955f18 2006-05-22 devnull 	/*
240 f8955f18 2006-05-22 devnull 	 * adjust e because s is 314159... not 3.14159...
241 f8955f18 2006-05-22 devnull 	 */
242 f8955f18 2006-05-22 devnull 	e -= NSIGNIF-1;
243 f8955f18 2006-05-22 devnull 	xfmtexp(s+NSIGNIF, e, 0);
244 f8955f18 2006-05-22 devnull 
245 f8955f18 2006-05-22 devnull 	/*
246 f8955f18 2006-05-22 devnull 	 * adjust conversion until strtod(s) == f exactly.
247 f8955f18 2006-05-22 devnull 	 */
248 f8955f18 2006-05-22 devnull 	for(i=0; i<10; i++) {
249 f8955f18 2006-05-22 devnull 		g = strtod(s, nil);
250 91c13e54 2004-02-29 devnull 		if(f > g) {
251 f8955f18 2006-05-22 devnull 			if(xadd1(s, NSIGNIF)) {
252 f8955f18 2006-05-22 devnull 				/* gained a digit */
253 91c13e54 2004-02-29 devnull 				e--;
254 f8955f18 2006-05-22 devnull 				xfmtexp(s+NSIGNIF, e, 0);
255 f8955f18 2006-05-22 devnull 			}
256 91c13e54 2004-02-29 devnull 			continue;
257 91c13e54 2004-02-29 devnull 		}
258 91c13e54 2004-02-29 devnull 		if(f < g) {
259 f8955f18 2006-05-22 devnull 			if(xsub1(s, NSIGNIF)) {
260 f8955f18 2006-05-22 devnull 				/* lost a digit */
261 91c13e54 2004-02-29 devnull 				e++;
262 f8955f18 2006-05-22 devnull 				xfmtexp(s+NSIGNIF, e, 0);
263 f8955f18 2006-05-22 devnull 			}
264 91c13e54 2004-02-29 devnull 			continue;
265 91c13e54 2004-02-29 devnull 		}
266 91c13e54 2004-02-29 devnull 		break;
267 91c13e54 2004-02-29 devnull 	}
268 91c13e54 2004-02-29 devnull 
269 91c13e54 2004-02-29 devnull 	/*
270 f8955f18 2006-05-22 devnull 	 * play with the decimal to try to simplify.
271 91c13e54 2004-02-29 devnull 	 */
272 91c13e54 2004-02-29 devnull 
273 91c13e54 2004-02-29 devnull 	/*
274 f8955f18 2006-05-22 devnull 	 * bump last few digits up to 9 if we can
275 91c13e54 2004-02-29 devnull 	 */
276 f8955f18 2006-05-22 devnull 	for(i=NSIGNIF-1; i>=NSIGNIF-3; i--) {
277 f8955f18 2006-05-22 devnull 		c = s[i];
278 f8955f18 2006-05-22 devnull 		if(c != '9') {
279 f8955f18 2006-05-22 devnull 			s[i] = '9';
280 f8955f18 2006-05-22 devnull 			g = strtod(s, nil);
281 f8955f18 2006-05-22 devnull 			if(g != f) {
282 f8955f18 2006-05-22 devnull 				s[i] = c;
283 f8955f18 2006-05-22 devnull 				break;
284 f8955f18 2006-05-22 devnull 			}
285 91c13e54 2004-02-29 devnull 		}
286 91c13e54 2004-02-29 devnull 	}
287 91c13e54 2004-02-29 devnull 
288 91c13e54 2004-02-29 devnull 	/*
289 f8955f18 2006-05-22 devnull 	 * add 1 in hopes of turning 9s to 0s
290 91c13e54 2004-02-29 devnull 	 */
291 f8955f18 2006-05-22 devnull 	if(s[NSIGNIF-1] == '9') {
292 f8955f18 2006-05-22 devnull 		strcpy(tmp, s);
293 f8955f18 2006-05-22 devnull 		ee = e;
294 f8955f18 2006-05-22 devnull 		if(xadd1(tmp, NSIGNIF)) {
295 f8955f18 2006-05-22 devnull 			ee--;
296 f8955f18 2006-05-22 devnull 			xfmtexp(tmp+NSIGNIF, ee, 0);
297 f8955f18 2006-05-22 devnull 		}
298 f8955f18 2006-05-22 devnull 		g = strtod(tmp, nil);
299 f8955f18 2006-05-22 devnull 		if(g == f) {
300 f8955f18 2006-05-22 devnull 			strcpy(s, tmp);
301 f8955f18 2006-05-22 devnull 			e = ee;
302 f8955f18 2006-05-22 devnull 		}
303 91c13e54 2004-02-29 devnull 	}
304 f8955f18 2006-05-22 devnull 	
305 91c13e54 2004-02-29 devnull 	/*
306 f8955f18 2006-05-22 devnull 	 * bump last few digits down to 0 as we can.
307 91c13e54 2004-02-29 devnull 	 */
308 f8955f18 2006-05-22 devnull 	for(i=NSIGNIF-1; i>=NSIGNIF-3; i--) {
309 f8955f18 2006-05-22 devnull 		c = s[i];
310 f8955f18 2006-05-22 devnull 		if(c != '0') {
311 f8955f18 2006-05-22 devnull 			s[i] = '0';
312 f8955f18 2006-05-22 devnull 			g = strtod(s, nil);
313 f8955f18 2006-05-22 devnull 			if(g != f) {
314 f8955f18 2006-05-22 devnull 				s[i] = c;
315 f8955f18 2006-05-22 devnull 				break;
316 f8955f18 2006-05-22 devnull 			}
317 f8955f18 2006-05-22 devnull 		}
318 91c13e54 2004-02-29 devnull 	}
319 91c13e54 2004-02-29 devnull 
320 91c13e54 2004-02-29 devnull 	/*
321 f8955f18 2006-05-22 devnull 	 * remove trailing zeros.
322 91c13e54 2004-02-29 devnull 	 */
323 f8955f18 2006-05-22 devnull 	ndigit = NSIGNIF;
324 f8955f18 2006-05-22 devnull 	while(ndigit > 1 && s[ndigit-1] == '0'){
325 f8955f18 2006-05-22 devnull 		e++;
326 f8955f18 2006-05-22 devnull 		--ndigit;
327 f8955f18 2006-05-22 devnull 	}
328 f8955f18 2006-05-22 devnull 	s[ndigit] = 0;
329 f8955f18 2006-05-22 devnull 	*exp = e;
330 f8955f18 2006-05-22 devnull 	*ns = ndigit;
331 f8955f18 2006-05-22 devnull 	errno = oerrno;
332 f8955f18 2006-05-22 devnull }
333 f8955f18 2006-05-22 devnull 
334 f8955f18 2006-05-22 devnull #ifdef PLAN9PORT
335 f8955f18 2006-05-22 devnull static char *special[] = { "NaN", "NaN", "+Inf", "+Inf", "-Inf", "-Inf" };
336 f8955f18 2006-05-22 devnull #else
337 f8955f18 2006-05-22 devnull static char *special[] = { "nan", "NAN", "inf", "INF", "-inf", "-INF" };
338 f8955f18 2006-05-22 devnull #endif
339 f8955f18 2006-05-22 devnull 
340 f8955f18 2006-05-22 devnull int
341 f8955f18 2006-05-22 devnull __efgfmt(Fmt *fmt)
342 f8955f18 2006-05-22 devnull {
343 f8955f18 2006-05-22 devnull 	char buf[NSIGNIF+10], *dot, *digits, *p, *s, suf[10], *t;
344 f8955f18 2006-05-22 devnull 	double f;
345 f8955f18 2006-05-22 devnull 	int c, chr, dotwid, e, exp, fl, ndigits, neg, newndigits;
346 f8955f18 2006-05-22 devnull 	int pad, point, prec, realchr, sign, sufwid, ucase, wid, z1, z2;
347 f8955f18 2006-05-22 devnull 	Rune r, *rs, *rt;
348 f8955f18 2006-05-22 devnull 	
349 f8955f18 2006-05-22 devnull 	f = va_arg(fmt->args, double);
350 f8955f18 2006-05-22 devnull 	
351 f8955f18 2006-05-22 devnull 	/* 
352 f8955f18 2006-05-22 devnull 	 * extract formatting flags
353 f8955f18 2006-05-22 devnull 	 */
354 f8955f18 2006-05-22 devnull 	fl = fmt->flags;
355 f8955f18 2006-05-22 devnull 	fmt->flags = 0;
356 f8955f18 2006-05-22 devnull 	prec = FDEFLT;
357 f8955f18 2006-05-22 devnull 	if(fl & FmtPrec)
358 f8955f18 2006-05-22 devnull 		prec = fmt->prec;
359 f8955f18 2006-05-22 devnull 	chr = fmt->r;
360 f8955f18 2006-05-22 devnull 	ucase = 0;
361 f8955f18 2006-05-22 devnull 	switch(chr) {
362 f8955f18 2006-05-22 devnull 	case 'A':
363 f8955f18 2006-05-22 devnull 	case 'E':
364 f8955f18 2006-05-22 devnull 	case 'F':
365 f8955f18 2006-05-22 devnull 	case 'G':
366 f8955f18 2006-05-22 devnull 		chr += 'a'-'A';
367 f8955f18 2006-05-22 devnull 		ucase = 1;
368 f8955f18 2006-05-22 devnull 		break;
369 f8955f18 2006-05-22 devnull 	}
370 f8955f18 2006-05-22 devnull 
371 f8955f18 2006-05-22 devnull 	/*
372 f8955f18 2006-05-22 devnull 	 * pick off special numbers.
373 f8955f18 2006-05-22 devnull 	 */
374 f8955f18 2006-05-22 devnull 	if(__isNaN(f)) {
375 f8955f18 2006-05-22 devnull 		s = special[0+ucase];
376 f8955f18 2006-05-22 devnull 	special:
377 f8955f18 2006-05-22 devnull 		fmt->flags = fl & (FmtWidth|FmtLeft);
378 f8955f18 2006-05-22 devnull 		return __fmtcpy(fmt, s, strlen(s), strlen(s));
379 f8955f18 2006-05-22 devnull 	}
380 f8955f18 2006-05-22 devnull 	if(__isInf(f, 1)) {
381 f8955f18 2006-05-22 devnull 		s = special[2+ucase];
382 f8955f18 2006-05-22 devnull 		goto special;
383 f8955f18 2006-05-22 devnull 	}
384 f8955f18 2006-05-22 devnull 	if(__isInf(f, -1)) {
385 f8955f18 2006-05-22 devnull 		s = special[4+ucase];
386 f8955f18 2006-05-22 devnull 		goto special;
387 f8955f18 2006-05-22 devnull 	}
388 f8955f18 2006-05-22 devnull 
389 f8955f18 2006-05-22 devnull 	/*
390 f8955f18 2006-05-22 devnull 	 * get exact representation.
391 f8955f18 2006-05-22 devnull 	 */
392 f8955f18 2006-05-22 devnull 	digits = buf;
393 f8955f18 2006-05-22 devnull 	xdtoa(f, digits, &exp, &neg, &ndigits);
394 f8955f18 2006-05-22 devnull 
395 f8955f18 2006-05-22 devnull 	/*
396 f8955f18 2006-05-22 devnull 	 * get locale's decimal point.
397 f8955f18 2006-05-22 devnull 	 */
398 f8955f18 2006-05-22 devnull 	dot = fmt->decimal;
399 f8955f18 2006-05-22 devnull 	if(dot == nil)
400 f8955f18 2006-05-22 devnull 		dot = ".";
401 f8955f18 2006-05-22 devnull 	dotwid = utflen(dot);
402 f8955f18 2006-05-22 devnull 
403 f8955f18 2006-05-22 devnull 	/*
404 f8955f18 2006-05-22 devnull 	 * now the formatting fun begins.
405 f8955f18 2006-05-22 devnull 	 * compute parameters for actual fmt:
406 f8955f18 2006-05-22 devnull 	 *
407 f8955f18 2006-05-22 devnull 	 *	pad: number of spaces to insert before/after field.
408 f8955f18 2006-05-22 devnull 	 *	z1: number of zeros to insert before digits
409 f8955f18 2006-05-22 devnull 	 *	z2: number of zeros to insert after digits
410 f8955f18 2006-05-22 devnull 	 *	point: number of digits to print before decimal point
411 f8955f18 2006-05-22 devnull 	 *	ndigits: number of digits to use from digits[]
412 f8955f18 2006-05-22 devnull 	 *	suf: trailing suffix, like "e-5"
413 f8955f18 2006-05-22 devnull 	 */
414 f8955f18 2006-05-22 devnull 	realchr = chr;
415 f8955f18 2006-05-22 devnull 	switch(chr){
416 f8955f18 2006-05-22 devnull 	case 'g':
417 f8955f18 2006-05-22 devnull 		/*
418 f8955f18 2006-05-22 devnull 		 * convert to at most prec significant digits. (prec=0 means 1)
419 f8955f18 2006-05-22 devnull 		 */
420 f8955f18 2006-05-22 devnull 		if(prec == 0)
421 f8955f18 2006-05-22 devnull 			prec = 1;
422 f8955f18 2006-05-22 devnull 		if(ndigits > prec) {
423 f8955f18 2006-05-22 devnull 			if(digits[prec] >= '5' && xadd1(digits, prec))
424 f8955f18 2006-05-22 devnull 				exp++;
425 f8955f18 2006-05-22 devnull 			exp += ndigits-prec;
426 f8955f18 2006-05-22 devnull 			ndigits = prec;
427 f8955f18 2006-05-22 devnull 		}
428 f8955f18 2006-05-22 devnull 		
429 f8955f18 2006-05-22 devnull 		/*
430 f8955f18 2006-05-22 devnull 		 * extra rules for %g (implemented below):
431 f8955f18 2006-05-22 devnull 		 *	trailing zeros removed after decimal unless FmtSharp.
432 f8955f18 2006-05-22 devnull 		 *	decimal point only if digit follows.
433 f8955f18 2006-05-22 devnull 		 */
434 f8955f18 2006-05-22 devnull 
435 f8955f18 2006-05-22 devnull 		/* fall through to %e */
436 f8955f18 2006-05-22 devnull 	default:
437 f8955f18 2006-05-22 devnull 	case 'e':
438 f8955f18 2006-05-22 devnull 		/* 
439 f8955f18 2006-05-22 devnull 		 * one significant digit before decimal, no leading zeros.
440 f8955f18 2006-05-22 devnull 		 */
441 f8955f18 2006-05-22 devnull 		point = 1;
442 f8955f18 2006-05-22 devnull 		z1 = 0;
443 f8955f18 2006-05-22 devnull 		
444 f8955f18 2006-05-22 devnull 		/*
445 f8955f18 2006-05-22 devnull 		 * decimal point is after ndigits digits right now.
446 f8955f18 2006-05-22 devnull 		 * slide to be after first.
447 f8955f18 2006-05-22 devnull 		 */
448 f8955f18 2006-05-22 devnull 		e  = exp + (ndigits-1);
449 f8955f18 2006-05-22 devnull 
450 f8955f18 2006-05-22 devnull 		/*
451 f8955f18 2006-05-22 devnull 		 * if this is %g, check exponent and convert prec
452 f8955f18 2006-05-22 devnull 		 */
453 f8955f18 2006-05-22 devnull 		if(realchr == 'g') {
454 f8955f18 2006-05-22 devnull 			if(-4 <= e && e < prec)
455 f8955f18 2006-05-22 devnull 				goto casef;
456 f8955f18 2006-05-22 devnull 			prec--;	/* one digit before decimal; rest after */
457 f8955f18 2006-05-22 devnull 		}
458 f8955f18 2006-05-22 devnull 
459 f8955f18 2006-05-22 devnull 		/*
460 f8955f18 2006-05-22 devnull 		 * compute trailing zero padding or truncate digits.
461 f8955f18 2006-05-22 devnull 		 */
462 f8955f18 2006-05-22 devnull 		if(1+prec >= ndigits)
463 f8955f18 2006-05-22 devnull 			z2 = 1+prec - ndigits;
464 f8955f18 2006-05-22 devnull 		else {
465 f8955f18 2006-05-22 devnull 			/*
466 f8955f18 2006-05-22 devnull 			 * truncate digits
467 f8955f18 2006-05-22 devnull 			 */
468 f8955f18 2006-05-22 devnull 			assert(realchr != 'g');
469 f8955f18 2006-05-22 devnull 			newndigits = 1+prec;
470 f8955f18 2006-05-22 devnull 			if(digits[newndigits] >= '5' && xadd1(digits, newndigits)) {
471 f8955f18 2006-05-22 devnull 				/*
472 f8955f18 2006-05-22 devnull 				 * had 999e4, now have 100e5
473 f8955f18 2006-05-22 devnull 				 */
474 f8955f18 2006-05-22 devnull 				e++;
475 a76c0fd4 2004-12-26 devnull 			}
476 f8955f18 2006-05-22 devnull 			ndigits = newndigits;
477 f8955f18 2006-05-22 devnull 			z2 = 0;
478 f8955f18 2006-05-22 devnull 		}
479 f8955f18 2006-05-22 devnull 		xfmtexp(suf, e, ucase);
480 f8955f18 2006-05-22 devnull 		sufwid = strlen(suf);
481 f8955f18 2006-05-22 devnull 		break;
482 f8955f18 2006-05-22 devnull 
483 f8955f18 2006-05-22 devnull 	casef:
484 f8955f18 2006-05-22 devnull 	case 'f':
485 f8955f18 2006-05-22 devnull 		/*
486 f8955f18 2006-05-22 devnull 		 * determine where digits go with respect to decimal point
487 f8955f18 2006-05-22 devnull 		 */
488 f8955f18 2006-05-22 devnull 		if(ndigits+exp > 0) {
489 f8955f18 2006-05-22 devnull 			point = ndigits+exp;
490 f8955f18 2006-05-22 devnull 			z1 = 0;
491 f8955f18 2006-05-22 devnull 		} else {
492 f8955f18 2006-05-22 devnull 			point = 1;
493 f8955f18 2006-05-22 devnull 			z1 = 1 + -(ndigits+exp);
494 f8955f18 2006-05-22 devnull 		}
495 f8955f18 2006-05-22 devnull 
496 f8955f18 2006-05-22 devnull 		/*
497 f8955f18 2006-05-22 devnull 		 * %g specifies prec = number of significant digits
498 f8955f18 2006-05-22 devnull 		 * convert to number of digits after decimal point
499 f8955f18 2006-05-22 devnull 		 */
500 f8955f18 2006-05-22 devnull 		if(realchr == 'g')
501 f8955f18 2006-05-22 devnull 			prec += z1 - point;
502 f8955f18 2006-05-22 devnull 
503 f8955f18 2006-05-22 devnull 		/*
504 f8955f18 2006-05-22 devnull 		 * compute trailing zero padding or truncate digits.
505 f8955f18 2006-05-22 devnull 		 */
506 f8955f18 2006-05-22 devnull 		if(point+prec >= z1+ndigits)
507 f8955f18 2006-05-22 devnull 			z2 = point+prec - (z1+ndigits);
508 f8955f18 2006-05-22 devnull 		else {
509 f8955f18 2006-05-22 devnull 			/*
510 f8955f18 2006-05-22 devnull 			 * truncate digits
511 f8955f18 2006-05-22 devnull 			 */
512 f8955f18 2006-05-22 devnull 			assert(realchr != 'g');
513 f8955f18 2006-05-22 devnull 			newndigits = point+prec - z1;
514 f8955f18 2006-05-22 devnull 			if(newndigits < 0) {
515 f8955f18 2006-05-22 devnull 				z1 += newndigits;
516 f8955f18 2006-05-22 devnull 				newndigits = 0;
517 f8955f18 2006-05-22 devnull 			} else if(newndigits == 0) {
518 f8955f18 2006-05-22 devnull 				/* perhaps round up */
519 f8955f18 2006-05-22 devnull 				if(digits[0] >= '5'){
520 f8955f18 2006-05-22 devnull 					digits[0] = '1';
521 f8955f18 2006-05-22 devnull 					newndigits = 1;
522 f8955f18 2006-05-22 devnull 					goto newdigit;
523 f8955f18 2006-05-22 devnull 				}
524 f8955f18 2006-05-22 devnull 			} else if(digits[newndigits] >= '5' && xadd1(digits, newndigits)) {
525 f8955f18 2006-05-22 devnull 				/*
526 f8955f18 2006-05-22 devnull 				 * digits was 999, is now 100; make it 1000
527 f8955f18 2006-05-22 devnull 				 */
528 f8955f18 2006-05-22 devnull 				digits[newndigits++] = '0';
529 f8955f18 2006-05-22 devnull 			newdigit:
530 f8955f18 2006-05-22 devnull 				/*
531 f8955f18 2006-05-22 devnull 				 * account for new digit
532 f8955f18 2006-05-22 devnull 				 */
533 f8955f18 2006-05-22 devnull 				if(z1)	/* 0.099 => 0.100 or 0.99 => 1.00*/
534 f8955f18 2006-05-22 devnull 					z1--;
535 f8955f18 2006-05-22 devnull 				else	/* 9.99 => 10.00 */
536 f8955f18 2006-05-22 devnull 					point++;
537 f8955f18 2006-05-22 devnull 			}
538 f8955f18 2006-05-22 devnull 			z2 = 0;
539 f8955f18 2006-05-22 devnull 			ndigits = newndigits;
540 f8955f18 2006-05-22 devnull 		}	
541 f8955f18 2006-05-22 devnull 		sufwid = 0;
542 f8955f18 2006-05-22 devnull 		break;
543 91c13e54 2004-02-29 devnull 	}
544 f8955f18 2006-05-22 devnull 	
545 f8955f18 2006-05-22 devnull 	/*
546 f8955f18 2006-05-22 devnull 	 * if %g is given without FmtSharp, remove trailing zeros.
547 f8955f18 2006-05-22 devnull 	 * must do after truncation, so that e.g. print %.3g 1.001
548 f8955f18 2006-05-22 devnull 	 * produces 1, not 1.00.  sorry, but them's the rules.
549 f8955f18 2006-05-22 devnull 	 */
550 f8955f18 2006-05-22 devnull 	if(realchr == 'g' && !(fl & FmtSharp)) {
551 f8955f18 2006-05-22 devnull 		if(z1+ndigits+z2 >= point) {
552 f8955f18 2006-05-22 devnull 			if(z1+ndigits < point)
553 f8955f18 2006-05-22 devnull 				z2 = point - (z1+ndigits);
554 f8955f18 2006-05-22 devnull 			else{
555 f8955f18 2006-05-22 devnull 				z2 = 0;
556 f8955f18 2006-05-22 devnull 				while(z1+ndigits > point && digits[ndigits-1] == '0')
557 f8955f18 2006-05-22 devnull 					ndigits--;
558 f8955f18 2006-05-22 devnull 			}
559 91c13e54 2004-02-29 devnull 		}
560 91c13e54 2004-02-29 devnull 	}
561 a76c0fd4 2004-12-26 devnull 
562 f8955f18 2006-05-22 devnull 	/*
563 f8955f18 2006-05-22 devnull 	 * compute width of all digits and decimal point and suffix if any
564 f8955f18 2006-05-22 devnull 	 */
565 f8955f18 2006-05-22 devnull 	wid = z1+ndigits+z2;
566 f8955f18 2006-05-22 devnull 	if(wid > point)
567 f8955f18 2006-05-22 devnull 		wid += dotwid;
568 f8955f18 2006-05-22 devnull 	else if(wid == point){
569 f8955f18 2006-05-22 devnull 		if(fl & FmtSharp)
570 f8955f18 2006-05-22 devnull 			wid += dotwid;
571 f8955f18 2006-05-22 devnull 		else
572 f8955f18 2006-05-22 devnull 			point++;	/* do not print any decimal point */
573 f8955f18 2006-05-22 devnull 	}
574 f8955f18 2006-05-22 devnull 	wid += sufwid;
575 a76c0fd4 2004-12-26 devnull 
576 f8955f18 2006-05-22 devnull 	/*
577 f8955f18 2006-05-22 devnull 	 * determine sign
578 f8955f18 2006-05-22 devnull 	 */
579 f8955f18 2006-05-22 devnull 	sign = 0;
580 f8955f18 2006-05-22 devnull 	if(neg)
581 f8955f18 2006-05-22 devnull 		sign = '-';
582 f8955f18 2006-05-22 devnull 	else if(fl & FmtSign)
583 f8955f18 2006-05-22 devnull 		sign = '+';
584 f8955f18 2006-05-22 devnull 	else if(fl & FmtSpace)
585 f8955f18 2006-05-22 devnull 		sign = ' ';
586 f8955f18 2006-05-22 devnull 	if(sign)
587 f8955f18 2006-05-22 devnull 		wid++;
588 a76c0fd4 2004-12-26 devnull 
589 f8955f18 2006-05-22 devnull 	/*
590 f8955f18 2006-05-22 devnull 	 * compute padding
591 f8955f18 2006-05-22 devnull 	 */
592 f8955f18 2006-05-22 devnull 	pad = 0;
593 f8955f18 2006-05-22 devnull 	if((fl & FmtWidth) && fmt->width > wid)
594 f8955f18 2006-05-22 devnull 		pad = fmt->width - wid;
595 f8955f18 2006-05-22 devnull 	if(pad && !(fl & FmtLeft) && (fl & FmtZero)){
596 f8955f18 2006-05-22 devnull 		z1 += pad;
597 f8955f18 2006-05-22 devnull 		point += pad;
598 f8955f18 2006-05-22 devnull 		pad = 0;
599 f8955f18 2006-05-22 devnull 	}
600 a76c0fd4 2004-12-26 devnull 
601 f8955f18 2006-05-22 devnull 	/*
602 f8955f18 2006-05-22 devnull 	 * format the actual field.  too bad about doing this twice.
603 f8955f18 2006-05-22 devnull 	 */
604 f8955f18 2006-05-22 devnull 	if(fmt->runes){
605 f8955f18 2006-05-22 devnull 		if(pad && !(fl & FmtLeft) && __rfmtpad(fmt, pad) < 0)
606 f8955f18 2006-05-22 devnull 			return -1;
607 f8955f18 2006-05-22 devnull 		rt = (Rune*)fmt->to;
608 f8955f18 2006-05-22 devnull 		rs = (Rune*)fmt->stop;
609 f8955f18 2006-05-22 devnull 		if(sign)
610 f8955f18 2006-05-22 devnull 			FMTRCHAR(fmt, rt, rs, sign);
611 f8955f18 2006-05-22 devnull 		while(z1>0 || ndigits>0 || z2>0) {
612 f8955f18 2006-05-22 devnull 			if(z1 > 0){
613 f8955f18 2006-05-22 devnull 				z1--;
614 f8955f18 2006-05-22 devnull 				c = '0';
615 f8955f18 2006-05-22 devnull 			}else if(ndigits > 0){
616 f8955f18 2006-05-22 devnull 				ndigits--;
617 f8955f18 2006-05-22 devnull 				c = *digits++;
618 d4f27433 2006-05-26 devnull 			}else{
619 f8955f18 2006-05-22 devnull 				z2--;
620 f8955f18 2006-05-22 devnull 				c = '0';
621 f8955f18 2006-05-22 devnull 			}
622 f8955f18 2006-05-22 devnull 			FMTRCHAR(fmt, rt, rs, c);
623 f8955f18 2006-05-22 devnull 			if(--point == 0) {
624 f8955f18 2006-05-22 devnull 				for(p = dot; *p; ){
625 f8955f18 2006-05-22 devnull 					p += chartorune(&r, p);
626 f8955f18 2006-05-22 devnull 					FMTRCHAR(fmt, rt, rs, r);
627 f8955f18 2006-05-22 devnull 				}
628 f8955f18 2006-05-22 devnull 			}
629 f8955f18 2006-05-22 devnull 		}
630 f8955f18 2006-05-22 devnull 		fmt->nfmt += rt - (Rune*)fmt->to;
631 f8955f18 2006-05-22 devnull 		fmt->to = rt;
632 f8955f18 2006-05-22 devnull 		if(sufwid && __fmtcpy(fmt, suf, sufwid, sufwid) < 0)
633 f8955f18 2006-05-22 devnull 			return -1;
634 f8955f18 2006-05-22 devnull 		if(pad && (fl & FmtLeft) && __rfmtpad(fmt, pad) < 0)
635 f8955f18 2006-05-22 devnull 			return -1;
636 f8955f18 2006-05-22 devnull 	}else{
637 f8955f18 2006-05-22 devnull 		if(pad && !(fl & FmtLeft) && __fmtpad(fmt, pad) < 0)
638 f8955f18 2006-05-22 devnull 			return -1;
639 f8955f18 2006-05-22 devnull 		t = (char*)fmt->to;
640 f8955f18 2006-05-22 devnull 		s = (char*)fmt->stop;
641 f8955f18 2006-05-22 devnull 		if(sign)
642 f8955f18 2006-05-22 devnull 			FMTCHAR(fmt, t, s, sign);
643 f8955f18 2006-05-22 devnull 		while(z1>0 || ndigits>0 || z2>0) {
644 f8955f18 2006-05-22 devnull 			if(z1 > 0){
645 f8955f18 2006-05-22 devnull 				z1--;
646 f8955f18 2006-05-22 devnull 				c = '0';
647 f8955f18 2006-05-22 devnull 			}else if(ndigits > 0){
648 f8955f18 2006-05-22 devnull 				ndigits--;
649 f8955f18 2006-05-22 devnull 				c = *digits++;
650 403fb41e 2006-05-28 devnull 			}else{
651 f8955f18 2006-05-22 devnull 				z2--;
652 f8955f18 2006-05-22 devnull 				c = '0';
653 f8955f18 2006-05-22 devnull 			}
654 f8955f18 2006-05-22 devnull 			FMTCHAR(fmt, t, s, c);
655 f8955f18 2006-05-22 devnull 			if(--point == 0)
656 f8955f18 2006-05-22 devnull 				for(p=dot; *p; p++)
657 f8955f18 2006-05-22 devnull 					FMTCHAR(fmt, t, s, *p);
658 f8955f18 2006-05-22 devnull 		}
659 f8955f18 2006-05-22 devnull 		fmt->nfmt += t - (char*)fmt->to;
660 f8955f18 2006-05-22 devnull 		fmt->to = t;
661 f8955f18 2006-05-22 devnull 		if(sufwid && __fmtcpy(fmt, suf, sufwid, sufwid) < 0)
662 f8955f18 2006-05-22 devnull 			return -1;
663 f8955f18 2006-05-22 devnull 		if(pad && (fl & FmtLeft) && __fmtpad(fmt, pad) < 0)
664 f8955f18 2006-05-22 devnull 			return -1;
665 f8955f18 2006-05-22 devnull 	}
666 f8955f18 2006-05-22 devnull 	return 0;
667 a76c0fd4 2004-12-26 devnull }
668 f8955f18 2006-05-22 devnull