WebSVN – planix.SVN – Blame – /os/branches/feature_posix/sys/src/ape/lib/fmt/fltfmt.c

Rev	Author	Line No.	Line
2	-	1	`/*`
		2	`* The authors of this software are Rob Pike and Ken Thompson.`
		3	`* Copyright (c) 2002 by Lucent Technologies.`
		4	`* Permission to use, copy, modify, and distribute this software for any`
		5	`* purpose without fee is hereby granted, provided that this entire notice`
		6	`* is included in all copies of any software which is or includes a copy`
		7	`* or modification of this software and in all copies of the supporting`
		8	`* documentation for such software.`
		9	`* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED`
		10	`* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY`
		11	`* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY`
		12	`* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.`
		13	`*/`
		14	`#include <stdio.h>`
		15	`#include <math.h>`
		16	`#include <float.h>`
		17	`#include <string.h>`
		18	`#include <stdlib.h>`
		19	`#include <errno.h>`
		20	`#include <stdarg.h>`
		21	`#include "fmt.h"`
		22	`#include "fmtdef.h"`
		23	`#include "nan.h"`
		24
		25	`enum`
		26	`{`
		27	`FDEFLT = 6,`
		28	`NSIGNIF = 17`
		29	`};`
		30
		31	`/*`
		32	`* first few powers of 10, enough for about 1/2 of the`
		33	`* total space for doubles.`
		34	`*/`
		35	`static double pows10[] =`
		36	`{`
		37	`1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,`
		38	`1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,`
		39	`1e20, 1e21, 1e22, 1e23, 1e24, 1e25, 1e26, 1e27, 1e28, 1e29,`
		40	`1e30, 1e31, 1e32, 1e33, 1e34, 1e35, 1e36, 1e37, 1e38, 1e39,`
		41	`1e40, 1e41, 1e42, 1e43, 1e44, 1e45, 1e46, 1e47, 1e48, 1e49,`
		42	`1e50, 1e51, 1e52, 1e53, 1e54, 1e55, 1e56, 1e57, 1e58, 1e59,`
		43	`1e60, 1e61, 1e62, 1e63, 1e64, 1e65, 1e66, 1e67, 1e68, 1e69,`
		44	`1e70, 1e71, 1e72, 1e73, 1e74, 1e75, 1e76, 1e77, 1e78, 1e79,`
		45	`1e80, 1e81, 1e82, 1e83, 1e84, 1e85, 1e86, 1e87, 1e88, 1e89,`
		46	`1e90, 1e91, 1e92, 1e93, 1e94, 1e95, 1e96, 1e97, 1e98, 1e99,`
		47	`1e100, 1e101, 1e102, 1e103, 1e104, 1e105, 1e106, 1e107, 1e108, 1e109,`
		48	`1e110, 1e111, 1e112, 1e113, 1e114, 1e115, 1e116, 1e117, 1e118, 1e119,`
		49	`1e120, 1e121, 1e122, 1e123, 1e124, 1e125, 1e126, 1e127, 1e128, 1e129,`
		50	`1e130, 1e131, 1e132, 1e133, 1e134, 1e135, 1e136, 1e137, 1e138, 1e139,`
		51	`1e140, 1e141, 1e142, 1e143, 1e144, 1e145, 1e146, 1e147, 1e148, 1e149,`
		52	`1e150, 1e151, 1e152, 1e153, 1e154, 1e155, 1e156, 1e157, 1e158, 1e159,`
		53	`};`
		54
		55	`static double`
		56	`pow10(int n)`
		57	`{`
		58	`double d;`
		59	`int neg;`
		60
		61	`neg = 0;`
		62	`if(n < 0){`
		63	`if(n < DBL_MIN_10_EXP){`
		64	`return 0.;`
		65	`}`
		66	`neg = 1;`
		67	`n = -n;`
		68	`}else if(n > DBL_MAX_10_EXP){`
		69	`return HUGE_VAL;`
		70	`}`
		71	`if(n < (int)(sizeof(pows10)/sizeof(pows10[0])))`
		72	`d = pows10[n];`
		73	`else{`
		74	`d = pows10[sizeof(pows10)/sizeof(pows10[0]) - 1];`
		75	`for(;;){`
		76	`n -= sizeof(pows10)/sizeof(pows10[0]) - 1;`
		77	`if(n < (int)(sizeof(pows10)/sizeof(pows10[0]))){`
		78	`d *= pows10[n];`
		79	`break;`
		80	`}`
		81	`d *= pows10[sizeof(pows10)/sizeof(pows10[0]) - 1];`
		82	`}`
		83	`}`
		84	`if(neg){`
		85	`return 1./d;`
		86	`}`
		87	`return d;`
		88	`}`
		89
		90	`static int`
		91	`xadd(char *a, int n, int v)`
		92	`{`
		93	`char *b;`
		94	`int c;`
		95
		96	`if(n < 0 \|\| n >= NSIGNIF)`
		97	`return 0;`
		98	`for(b = a+n; b >= a; b--) {`
		99	`c = *b + v;`
		100	`if(c <= '9') {`
		101	`*b = c;`
		102	`return 0;`
		103	`}`
		104	`*b = '0';`
		105	`v = 1;`
		106	`}`
		107	`a = '1'; / overflow adding */`
		108	`return 1;`
		109	`}`
		110
		111	`static int`
		112	`xsub(char *a, int n, int v)`
		113	`{`
		114	`char *b;`
		115	`int c;`
		116
		117	`for(b = a+n; b >= a; b--) {`
		118	`c = *b - v;`
		119	`if(c >= '0') {`
		120	`*b = c;`
		121	`return 0;`
		122	`}`
		123	`*b = '9';`
		124	`v = 1;`
		125	`}`
		126	`a = '9'; / underflow subtracting */`
		127	`return 1;`
		128	`}`
		129
		130	`static void`
		131	`xaddexp(char *p, int e)`
		132	`{`
		133	`char se[9];`
		134	`int i;`
		135
		136	`*p++ = 'e';`
		137	`if(e < 0) {`
		138	`*p++ = '-';`
		139	`e = -e;`
		140	`}`
		141	`i = 0;`
		142	`while(e) {`
		143	`se[i++] = e % 10 + '0';`
		144	`e /= 10;`
		145	`}`
		146	`if(i == 0) {`
		147	`*p++ = '0';`
		148	`} else {`
		149	`while(i > 0)`
		150	`*p++ = se[--i];`
		151	`}`
		152	`*p = '\0';`
		153	`}`
		154
		155	`static char*`
		156	`xdodtoa(char s1, double f, int chr, int prec, int decpt, int *rsign)`
		157	`{`
		158	`char s2[NSIGNIF+10];`
		159	`double g, h;`
		160	`int e, d, i;`
		161	`int c2, sign, oerr;`
		162
		163	`if(chr == 'F')`
		164	`chr = 'f';`
		165	`if(prec > NSIGNIF)`
		166	`prec = NSIGNIF;`
		167	`if(prec < 0)`
		168	`prec = 0;`
		169	`if(__isNaN(f)) {`
		170	`*decpt = 9999;`
		171	`*rsign = 0;`
		172	`strcpy(s1, "nan");`
		173	`return &s1[3];`
		174	`}`
		175	`sign = 0;`
		176	`if(f < 0) {`
		177	`f = -f;`
		178	`sign++;`
		179	`}`
		180	`*rsign = sign;`
		181	`if(__isInf(f, 1) \|\| __isInf(f, -1)) {`
		182	`*decpt = 9999;`
		183	`strcpy(s1, "inf");`
		184	`return &s1[3];`
		185	`}`
		186
		187	`e = 0;`
		188	`g = f;`
		189	`if(g != 0) {`
		190	`frexp(f, &e);`
		191	`e = (int)(e * .301029995664);`
		192	`if(e >= -150 && e <= +150) {`
		193	`d = 0;`
		194	`h = f;`
		195	`} else {`
		196	`d = e/2;`
		197	`h = f * pow10(-d);`
		198	`}`
		199	`g = h * pow10(d-e);`
		200	`while(g < 1) {`
		201	`e--;`
		202	`g = h * pow10(d-e);`
		203	`}`
		204	`while(g >= 10) {`
		205	`e++;`
		206	`g = h * pow10(d-e);`
		207	`}`
		208	`}`
		209
		210	`/*`
		211	`* convert NSIGNIF digits and convert`
		212	`* back to get accuracy.`
		213	`*/`
		214	`for(i=0; i<NSIGNIF; i++) {`
		215	`d = (int)g;`
		216	`s1[i] = d + '0';`
		217	`g = (g - d) * 10;`
		218	`}`
		219	`s1[i] = 0;`
		220
		221	`/*`
		222	`* try decimal rounding to eliminate 9s`
		223	`*/`
		224	`c2 = prec + 1;`
		225	`if(chr == 'f')`
		226	`c2 += e;`
		227	`oerr = errno;`
		228	`if(c2 >= NSIGNIF-2) {`
		229	`strcpy(s2, s1);`
		230	`d = e;`
		231	`s1[NSIGNIF-2] = '0';`
		232	`s1[NSIGNIF-1] = '0';`
		233	`xaddexp(s1+NSIGNIF, e-NSIGNIF+1);`
		234	`g = fmtstrtod(s1, nil);`
		235	`if(g == f)`
		236	`goto found;`
		237	`if(xadd(s1, NSIGNIF-3, 1)) {`
		238	`e++;`
		239	`xaddexp(s1+NSIGNIF, e-NSIGNIF+1);`
		240	`}`
		241	`g = fmtstrtod(s1, nil);`
		242	`if(g == f)`
		243	`goto found;`
		244	`strcpy(s1, s2);`
		245	`e = d;`
		246	`}`
		247
		248	`/*`
		249	`* convert back so s1 gets exact answer`
		250	`*/`
		251	`for(d = 0; d < 10; d++) {`
		252	`xaddexp(s1+NSIGNIF, e-NSIGNIF+1);`
		253	`g = fmtstrtod(s1, nil);`
		254	`if(f > g) {`
		255	`if(xadd(s1, NSIGNIF-1, 1))`
		256	`e--;`
		257	`continue;`
		258	`}`
		259	`if(f < g) {`
		260	`if(xsub(s1, NSIGNIF-1, 1))`
		261	`e++;`
		262	`continue;`
		263	`}`
		264	`break;`
		265	`}`
		266
		267	`found:`
		268	`errno = oerr;`
		269
		270	`/*`
		271	`* round & adjust 'f' digits`
		272	`*/`
		273	`c2 = prec + 1;`
		274	`if(chr == 'f'){`
		275	`if(xadd(s1, c2+e, 5))`
		276	`e++;`
		277	`c2 += e;`
		278	`if(c2 < 0){`
		279	`c2 = 0;`
		280	`e = -prec - 1;`
		281	`}`
		282	`}else{`
		283	`if(xadd(s1, c2, 5))`
		284	`e++;`
		285	`}`
		286	`if(c2 > NSIGNIF){`
		287	`c2 = NSIGNIF;`
		288	`}`
		289
		290	`*decpt = e + 1;`
		291
		292	`/*`
		293	`* terminate the converted digits`
		294	`*/`
		295	`s1[c2] = '\0';`
		296	`return &s1[c2];`
		297	`}`
		298
		299	`/*`
		300	`* this function works like the standard dtoa, if you want it.`
		301	`*/`
		302	`#if 0`
		303	`static char*`
		304	`__dtoa(double f, int mode, int ndigits, int decpt, int rsign, char **rve)`
		305	`{`
		306	`static char s2[NSIGNIF + 10];`
		307	`char *es;`
		308	`int chr, prec;`
		309
		310	`switch(mode) {`
		311	`/* like 'e' */`
		312	`case 2:`
		313	`case 4:`
		314	`case 6:`
		315	`case 8:`
		316	`chr = 'e';`
		317	`break;`
		318	`/* like 'g' */`
		319	`case 0:`
		320	`case 1:`
		321	`default:`
		322	`chr = 'g';`
		323	`break;`
		324	`/* like 'f' */`
		325	`case 3:`
		326	`case 5:`
		327	`case 7:`
		328	`case 9:`
		329	`chr = 'f';`
		330	`break;`
		331	`}`
		332
		333	`if(chr != 'f' && ndigits){`
		334	`ndigits--;`
		335	`}`
		336	`prec = ndigits;`
		337	`if(prec > NSIGNIF)`
		338	`prec = NSIGNIF;`
		339	`if(ndigits == 0)`
		340	`prec = NSIGNIF;`
		341	`es = xdodtoa(s2, f, chr, prec, decpt, rsign);`
		342
		343	`/*`
		344	`* strip trailing 0`
		345	`*/`
		346	`for(; es > s2 + 1; es--){`
		347	`if(es[-1] != '0'){`
		348	`break;`
		349	`}`
		350	`}`
		351	`*es = '\0';`
		352	`if(rve != NULL)`
		353	`*rve = es;`
		354	`return s2;`
		355	`}`
		356	`#endif`
		357
		358	`static int`
		359	`fmtzdotpad(Fmt *f, int n, int pt)`
		360	`{`
		361	`char t, s;`
		362	`int i;`
		363	`Rune rt, rs;`
		364
		365	`if(f->runes){`
		366	`rt = (Rune*)f->to;`
		367	`rs = (Rune*)f->stop;`
		368	`for(i = 0; i < n; i++){`
		369	`if(i == pt){`
		370	`FMTRCHAR(f, rt, rs, '.');`
		371	`}`
		372	`FMTRCHAR(f, rt, rs, '0');`
		373	`}`
		374	`f->nfmt += rt - (Rune*)f->to;`
		375	`f->to = rt;`
		376	`}else{`
		377	`t = (char*)f->to;`
		378	`s = (char*)f->stop;`
		379	`for(i = 0; i < n; i++){`
		380	`if(i == pt){`
		381	`FMTCHAR(f, t, s, '.');`
		382	`}`
		383	`FMTCHAR(f, t, s, '0');`
		384	`}`
		385	`f->nfmt += t - (char *)f->to;`
		386	`f->to = t;`
		387	`}`
		388	`return 0;`
		389	`}`
		390
		391	`int`
		392	`__efgfmt(Fmt *fmt)`
		393	`{`
		394	`double f;`
		395	`char s1[NSIGNIF+10];`
		396	`int e, d, n;`
		397	`int c1, c2, c3, c4, ucase, sign, chr, prec, fl;`
		398
		399	`f = va_arg(fmt->args, double);`
		400	`prec = FDEFLT;`
		401	`fl = fmt->flags;`
		402	`fmt->flags = 0;`
		403	`if(fl & FmtPrec)`
		404	`prec = fmt->prec;`
		405	`chr = fmt->r;`
		406	`ucase = 0;`
		407	`if(chr == 'E'){`
		408	`chr = 'e';`
		409	`ucase = 1;`
		410	`}else if(chr == 'F'){`
		411	`chr = 'f';`
		412	`ucase = 1;`
		413	`}else if(chr == 'G'){`
		414	`chr = 'g';`
		415	`ucase = 1;`
		416	`}`
		417	`if(prec > 0 && chr == 'g')`
		418	`prec--;`
		419	`if(prec < 0)`
		420	`prec = 0;`
		421
		422	`xdodtoa(s1, f, chr, prec, &e, &sign);`
		423	`e--;`
		424	`if(s1 == 'i' \|\| s1 == 'n'){`
		425	`if(ucase){`
		426	`if(*s1 == 'i'){`
		427	`strcpy(s1, "INF");`
		428	`}else{`
		429	`strcpy(s1, "NAN");`
		430	`}`
		431	`}`
		432	`fmt->flags = fl & (FmtWidth\|FmtLeft);`
		433	`return __fmtcpy(fmt, (const void*)s1, 3, 3);`
		434	`}`
		435
		436	`/*`
		437	`* copy into final place`
		438	`* c1 digits of leading '0'`
		439	`* c2 digits from conversion`
		440	`* c3 digits of trailing '0'`
		441	`* c4 digits after '.'`
		442	`*/`
		443	`c1 = 0;`
		444	`c2 = prec + 1;`
		445	`c3 = 0;`
		446	`c4 = prec;`
		447	`switch(chr) {`
		448	`default:`
		449	`chr = 'e';`
		450	`break;`
		451	`case 'g':`
		452	`/*`
		453	`* decide on 'e' of 'f' style convers`
		454	`*/`
		455	`if(e >= -4 && e <= prec) {`
		456	`c1 = -e;`
		457	`c4 = prec - e;`
		458	`chr = 'h'; /* flag for 'f' style */`
		459	`}`
		460	`break;`
		461	`case 'f':`
		462	`c1 = -e;`
		463	`if(c1 > prec)`
		464	`c1 = prec + 1;`
		465	`c2 += e;`
		466	`break;`
		467	`}`
		468
		469	`/*`
		470	`* clean up c1 c2 and c3`
		471	`*/`
		472	`if(c1 < 0)`
		473	`c1 = 0;`
		474	`if(c2 < 0)`
		475	`c2 = 0;`
		476	`if(c2 > NSIGNIF) {`
		477	`c3 = c2-NSIGNIF;`
		478	`c2 = NSIGNIF;`
		479	`}`
		480
		481	`/*`
		482	`* trim trailing zeros for %g`
		483	`*/`
		484	`if(!(fl & FmtSharp)`
		485	`&& (chr == 'g' \|\| chr == 'h')){`
		486	`if(c4 >= c3){`
		487	`c4 -= c3;`
		488	`c3 = 0;`
		489	`}else{`
		490	`c3 -= c4;`
		491	`c4 = 0;`
		492	`}`
		493	`while(c4 && c2 > 1 && s1[c2 - 1] == '0'){`
		494	`c4--;`
		495	`c2--;`
		496	`}`
		497	`}`
		498
		499	`/*`
		500	`* calculate the total length`
		501	`*/`
		502	`n = c1 + c2 + c3;`
		503	`if(sign \|\| (fl & (FmtSign\|FmtSpace)))`
		504	`n++;`
		505	`if(c4 \|\| (fl & FmtSharp)){`
		506	`n++;`
		507	`}`
		508	`if(chr == 'e' \|\| chr == 'g'){`
		509	`n += 4;`
		510	`if(e >= 100)`
		511	`n++;`
		512	`}`
		513
		514	`/*`
		515	`* pad to width if right justified`
		516	`*/`
		517	`if((fl & (FmtWidth\|FmtLeft)) == FmtWidth && n < fmt->width){`
		518	`if(fl & FmtZero){`
		519	`c1 += fmt->width - n;`
		520	`}else{`
		521	`if(__fmtpad(fmt, fmt->width - n) < 0){`
		522	`return -1;`
		523	`}`
		524	`}`
		525	`}`
		526
		527	`/*`
		528	`* sign`
		529	`*/`
		530	`d = 0;`
		531	`if(sign)`
		532	`d = '-';`
		533	`else if(fl & FmtSign)`
		534	`d = '+';`
		535	`else if(fl & FmtSpace)`
		536	`d = ' ';`
		537	`if(d && fmtrune(fmt, d) < 0){`
		538	`return -1;`
		539	`}`
		540
		541	`/*`
		542	`* copy digits`
		543	`*/`
		544	`c4 = c1 + c2 + c3 - c4;`
		545	`if(c1 > 0){`
		546	`if(fmtzdotpad(fmt, c1, c4) < 0){`
		547	`return -1;`
		548	`}`
		549	`c4 -= c1;`
		550	`}`
		551	`d = 0;`
		552	`if(c4 >= 0 && c4 < c2){`
		553	`if(__fmtcpy(fmt, s1, c4, c4) < 0 \|\| fmtrune(fmt, '.') < 0)`
		554	`return -1;`
		555	`d = c4;`
		556	`c2 -= c4;`
		557	`c4 = -1;`
		558	`}`
		559	`if(__fmtcpy(fmt, (const void*)(s1 + d), c2, c2) < 0){`
		560	`return -1;`
		561	`}`
		562	`c4 -= c2;`
		563	`if(c3 > 0){`
		564	`if(fmtzdotpad(fmt, c3, c4) < 0){`
		565	`return -1;`
		566	`}`
		567	`c4 -= c3;`
		568	`}`
		569
		570	`/*`
		571	`* strip trailing '0' on g conv`
		572	`*/`
		573	`if((fl & FmtSharp) && c4 == 0 && fmtrune(fmt, '.') < 0){`
		574	`return -1;`
		575	`}`
		576	`if(chr == 'e' \|\| chr == 'g') {`
		577	`d = 0;`
		578	`if(ucase)`
		579	`s1[d++] = 'E';`
		580	`else`
		581	`s1[d++] = 'e';`
		582	`c1 = e;`
		583	`if(c1 < 0) {`
		584	`s1[d++] = '-';`
		585	`c1 = -c1;`
		586	`} else`
		587	`s1[d++] = '+';`
		588	`if(c1 >= 100) {`
		589	`s1[d++] = c1/100 + '0';`
		590	`c1 = c1%100;`
		591	`}`
		592	`s1[d++] = c1/10 + '0';`
		593	`s1[d++] = c1%10 + '0';`
		594	`if(__fmtcpy(fmt, s1, d, d) < 0){`
		595	`return -1;`
		596	`}`
		597	`}`
		598	`if((fl & (FmtWidth\|FmtLeft)) == (FmtWidth\|FmtLeft) && n < fmt->width){`
		599	`if(__fmtpad(fmt, fmt->width - n) < 0){`
		600	`return -1;`
		601	`}`
		602	`}`
		603	`return 0;`
		604	`}`

Subversion Repositories planix.SVN

(root)/os/branches/feature_posix/sys/src/ape/lib/fmt/fltfmt.c – Rev 2