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-rw-r--r--src/libfmt/fltfmt.c610
1 files changed, 610 insertions, 0 deletions
diff --git a/src/libfmt/fltfmt.c b/src/libfmt/fltfmt.c
new file mode 100644
index 00000000..234f03d9
--- /dev/null
+++ b/src/libfmt/fltfmt.c
@@ -0,0 +1,610 @@
+/*
+ * The authors of this software are Rob Pike and Ken Thompson.
+ * Copyright (c) 2002 by Lucent Technologies.
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose without fee is hereby granted, provided that this entire notice
+ * is included in all copies of any software which is or includes a copy
+ * or modification of this software and in all copies of the supporting
+ * documentation for such software.
+ * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
+ * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
+ * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
+ */
+#include <stdio.h>
+#include <math.h>
+#include <float.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <stdarg.h>
+#include "fmt.h"
+#include "fmtdef.h"
+#include "nan.h"
+
+enum
+{
+ FDEFLT = 6,
+ NSIGNIF = 17
+};
+
+/*
+ * first few powers of 10, enough for about 1/2 of the
+ * total space for doubles.
+ */
+static double pows10[] =
+{
+ 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
+ 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
+ 1e20, 1e21, 1e22, 1e23, 1e24, 1e25, 1e26, 1e27, 1e28, 1e29,
+ 1e30, 1e31, 1e32, 1e33, 1e34, 1e35, 1e36, 1e37, 1e38, 1e39,
+ 1e40, 1e41, 1e42, 1e43, 1e44, 1e45, 1e46, 1e47, 1e48, 1e49,
+ 1e50, 1e51, 1e52, 1e53, 1e54, 1e55, 1e56, 1e57, 1e58, 1e59,
+ 1e60, 1e61, 1e62, 1e63, 1e64, 1e65, 1e66, 1e67, 1e68, 1e69,
+ 1e70, 1e71, 1e72, 1e73, 1e74, 1e75, 1e76, 1e77, 1e78, 1e79,
+ 1e80, 1e81, 1e82, 1e83, 1e84, 1e85, 1e86, 1e87, 1e88, 1e89,
+ 1e90, 1e91, 1e92, 1e93, 1e94, 1e95, 1e96, 1e97, 1e98, 1e99,
+ 1e100, 1e101, 1e102, 1e103, 1e104, 1e105, 1e106, 1e107, 1e108, 1e109,
+ 1e110, 1e111, 1e112, 1e113, 1e114, 1e115, 1e116, 1e117, 1e118, 1e119,
+ 1e120, 1e121, 1e122, 1e123, 1e124, 1e125, 1e126, 1e127, 1e128, 1e129,
+ 1e130, 1e131, 1e132, 1e133, 1e134, 1e135, 1e136, 1e137, 1e138, 1e139,
+ 1e140, 1e141, 1e142, 1e143, 1e144, 1e145, 1e146, 1e147, 1e148, 1e149,
+ 1e150, 1e151, 1e152, 1e153, 1e154, 1e155, 1e156, 1e157, 1e158, 1e159,
+};
+
+static double
+pow10(int n)
+{
+ double d;
+ int neg;
+
+ neg = 0;
+ if(n < 0){
+ if(n < DBL_MIN_10_EXP){
+ return 0.;
+ }
+ neg = 1;
+ n = -n;
+ }else if(n > DBL_MAX_10_EXP){
+ return HUGE_VAL;
+ }
+ if(n < (int)(sizeof(pows10)/sizeof(pows10[0])))
+ d = pows10[n];
+ else{
+ d = pows10[sizeof(pows10)/sizeof(pows10[0]) - 1];
+ for(;;){
+ n -= sizeof(pows10)/sizeof(pows10[0]) - 1;
+ if(n < (int)(sizeof(pows10)/sizeof(pows10[0]))){
+ d *= pows10[n];
+ break;
+ }
+ d *= pows10[sizeof(pows10)/sizeof(pows10[0]) - 1];
+ }
+ }
+ if(neg){
+ return 1./d;
+ }
+ return d;
+}
+
+static int
+xadd(char *a, int n, int v)
+{
+ char *b;
+ int c;
+
+ if(n < 0 || n >= NSIGNIF)
+ return 0;
+ for(b = a+n; b >= a; b--) {
+ c = *b + v;
+ if(c <= '9') {
+ *b = c;
+ return 0;
+ }
+ *b = '0';
+ v = 1;
+ }
+ *a = '1'; /* overflow adding */
+ return 1;
+}
+
+static int
+xsub(char *a, int n, int v)
+{
+ char *b;
+ int c;
+
+ for(b = a+n; b >= a; b--) {
+ c = *b - v;
+ if(c >= '0') {
+ *b = c;
+ return 0;
+ }
+ *b = '9';
+ v = 1;
+ }
+ *a = '9'; /* underflow subtracting */
+ return 1;
+}
+
+static void
+xaddexp(char *p, int e)
+{
+ char se[9];
+ int i;
+
+ *p++ = 'e';
+ if(e < 0) {
+ *p++ = '-';
+ e = -e;
+ }
+ i = 0;
+ while(e) {
+ se[i++] = e % 10 + '0';
+ e /= 10;
+ }
+ if(i == 0) {
+ *p++ = '0';
+ } else {
+ while(i > 0)
+ *p++ = se[--i];
+ }
+ *p++ = '\0';
+}
+
+static char*
+xdodtoa(char *s1, double f, int chr, int prec, int *decpt, int *rsign)
+{
+ char s2[NSIGNIF+10];
+ double g, h;
+ int e, d, i;
+ int c2, sign, oerr;
+
+ if(chr == 'F')
+ chr = 'f';
+ if(prec > NSIGNIF)
+ prec = NSIGNIF;
+ if(prec < 0)
+ prec = 0;
+ if(__isNaN(f)) {
+ *decpt = 9999;
+ *rsign = 0;
+ strcpy(s1, "nan");
+ return &s1[3];
+ }
+ sign = 0;
+ if(f < 0) {
+ f = -f;
+ sign++;
+ }
+ *rsign = sign;
+ if(__isInf(f, 1) || __isInf(f, -1)) {
+ *decpt = 9999;
+ strcpy(s1, "inf");
+ return &s1[3];
+ }
+
+ e = 0;
+ g = f;
+ if(g != 0) {
+ frexp(f, &e);
+ e = (int)(e * .301029995664);
+ if(e >= -150 && e <= +150) {
+ d = 0;
+ h = f;
+ } else {
+ d = e/2;
+ h = f * pow10(-d);
+ }
+ g = h * pow10(d-e);
+ while(g < 1) {
+ e--;
+ g = h * pow10(d-e);
+ }
+ while(g >= 10) {
+ e++;
+ g = h * pow10(d-e);
+ }
+ }
+
+ /*
+ * convert NSIGNIF digits and convert
+ * back to get accuracy.
+ */
+ for(i=0; i<NSIGNIF; i++) {
+ d = (int)g;
+ s1[i] = d + '0';
+ g = (g - d) * 10;
+ }
+ s1[i] = 0;
+
+ /*
+ * try decimal rounding to eliminate 9s
+ */
+ c2 = prec + 1;
+ if(chr == 'f')
+ c2 += e;
+ oerr = errno;
+ if(c2 >= NSIGNIF-2) {
+ strcpy(s2, s1);
+ d = e;
+ s1[NSIGNIF-2] = '0';
+ s1[NSIGNIF-1] = '0';
+ xaddexp(s1+NSIGNIF, e-NSIGNIF+1);
+ g = fmtstrtod(s1, nil);
+ if(g == f)
+ goto found;
+ if(xadd(s1, NSIGNIF-3, 1)) {
+ e++;
+ xaddexp(s1+NSIGNIF, e-NSIGNIF+1);
+ }
+ g = fmtstrtod(s1, nil);
+ if(g == f)
+ goto found;
+ strcpy(s1, s2);
+ e = d;
+ }
+
+ /*
+ * convert back so s1 gets exact answer
+ */
+ for(d = 0; d < 10; d++) {
+ xaddexp(s1+NSIGNIF, e-NSIGNIF+1);
+ g = fmtstrtod(s1, nil);
+ if(f > g) {
+ if(xadd(s1, NSIGNIF-1, 1))
+ e--;
+ continue;
+ }
+ if(f < g) {
+ if(xsub(s1, NSIGNIF-1, 1))
+ e++;
+ continue;
+ }
+ break;
+ }
+
+found:
+ errno = oerr;
+
+ /*
+ * sign
+ */
+ d = 0;
+ i = 0;
+
+ /*
+ * round & adjust 'f' digits
+ */
+ c2 = prec + 1;
+ if(chr == 'f'){
+ if(xadd(s1, c2+e, 5))
+ e++;
+ c2 += e;
+ if(c2 < 0){
+ c2 = 0;
+ e = -prec - 1;
+ }
+ }else{
+ if(xadd(s1, c2, 5))
+ e++;
+ }
+ if(c2 > NSIGNIF){
+ c2 = NSIGNIF;
+ }
+
+ *decpt = e + 1;
+
+ /*
+ * terminate the converted digits
+ */
+ s1[c2] = '\0';
+ return &s1[c2];
+}
+
+/*
+ * this function works like the standard dtoa, if you want it.
+ */
+#if 0
+static char*
+__dtoa(double f, int mode, int ndigits, int *decpt, int *rsign, char **rve)
+{
+ static char s2[NSIGNIF + 10];
+ char *es;
+ int chr, prec;
+
+ switch(mode) {
+ /* like 'e' */
+ case 2:
+ case 4:
+ case 6:
+ case 8:
+ chr = 'e';
+ break;
+ /* like 'g' */
+ case 0:
+ case 1:
+ default:
+ chr = 'g';
+ break;
+ /* like 'f' */
+ case 3:
+ case 5:
+ case 7:
+ case 9:
+ chr = 'f';
+ break;
+ }
+
+ if(chr != 'f' && ndigits){
+ ndigits--;
+ }
+ prec = ndigits;
+ if(prec > NSIGNIF)
+ prec = NSIGNIF;
+ if(ndigits == 0)
+ prec = NSIGNIF;
+ es = xdodtoa(s2, f, chr, prec, decpt, rsign);
+
+ /*
+ * strip trailing 0
+ */
+ for(; es > s2 + 1; es--){
+ if(es[-1] != '0'){
+ break;
+ }
+ }
+ *es = '\0';
+ if(rve != NULL)
+ *rve = es;
+ return s2;
+}
+#endif
+
+static int
+fmtzdotpad(Fmt *f, int n, int pt)
+{
+ char *t, *s;
+ int i;
+ Rune *rt, *rs;
+
+ if(f->runes){
+ rt = (Rune*)f->to;
+ rs = (Rune*)f->stop;
+ for(i = 0; i < n; i++){
+ if(i == pt){
+ FMTRCHAR(f, rt, rs, '.');
+ }
+ FMTRCHAR(f, rt, rs, '0');
+ }
+ f->nfmt += rt - (Rune*)f->to;
+ f->to = rt;
+ }else{
+ t = (char*)f->to;
+ s = (char*)f->stop;
+ for(i = 0; i < n; i++){
+ if(i == pt){
+ FMTCHAR(f, t, s, '.');
+ }
+ FMTCHAR(f, t, s, '0');
+ }
+ f->nfmt += t - (char *)f->to;
+ f->to = t;
+ }
+ return 0;
+}
+
+int
+__efgfmt(Fmt *fmt)
+{
+ double f;
+ char s1[NSIGNIF+10];
+ int e, d, n;
+ int c1, c2, c3, c4, ucase, sign, chr, prec, fl;
+
+ f = va_arg(fmt->args, double);
+ prec = FDEFLT;
+ fl = fmt->flags;
+ fmt->flags = 0;
+ if(fl & FmtPrec)
+ prec = fmt->prec;
+ chr = fmt->r;
+ ucase = 0;
+ if(chr == 'E'){
+ chr = 'e';
+ ucase = 1;
+ }else if(chr == 'F'){
+ chr = 'f';
+ ucase = 1;
+ }else if(chr == 'G'){
+ chr = 'g';
+ ucase = 1;
+ }
+ if(prec > 0 && chr == 'g')
+ prec--;
+ if(prec < 0)
+ prec = 0;
+
+ xdodtoa(s1, f, chr, prec, &e, &sign);
+ e--;
+ if(*s1 == 'i' || *s1 == 'n'){
+ if(ucase){
+ if(*s1 == 'i'){
+ strcpy(s1, "INF");
+ }else{
+ strcpy(s1, "NAN");
+ }
+ }
+ fmt->flags = fl & (FmtWidth|FmtLeft);
+ return __fmtcpy(fmt, (const void*)s1, 3, 3);
+ }
+
+ /*
+ * copy into final place
+ * c1 digits of leading '0'
+ * c2 digits from conversion
+ * c3 digits of trailing '0'
+ * c4 digits after '.'
+ */
+ c1 = 0;
+ c2 = prec + 1;
+ c3 = 0;
+ c4 = prec;
+ switch(chr) {
+ default:
+ chr = 'e';
+ break;
+ case 'g':
+ /*
+ * decide on 'e' of 'f' style convers
+ */
+ if(e >= -4 && e <= prec) {
+ c1 = -e;
+ c4 = prec - e;
+ chr = 'h'; /* flag for 'f' style */
+ }
+ break;
+ case 'f':
+ c1 = -e;
+ if(c1 > prec)
+ c1 = prec + 1;
+ c2 += e;
+ break;
+ }
+
+ /*
+ * clean up c1 c2 and c3
+ */
+ if(c1 < 0)
+ c1 = 0;
+ if(c2 < 0)
+ c2 = 0;
+ if(c2 > NSIGNIF) {
+ c3 = c2-NSIGNIF;
+ c2 = NSIGNIF;
+ }
+
+ /*
+ * trim trailing zeros for %g
+ */
+ if(!(fl & FmtSharp)
+ && (chr == 'g' || chr == 'h')){
+ if(c4 >= c3){
+ c4 -= c3;
+ c3 = 0;
+ }else{
+ c3 -= c4;
+ c4 = 0;
+ }
+ while(c4 && c2 > 1 && s1[c2 - 1] == '0'){
+ c4--;
+ c2--;
+ }
+ }
+
+ /*
+ * calculate the total length
+ */
+ n = c1 + c2 + c3;
+ if(sign || (fl & (FmtSign|FmtSpace)))
+ n++;
+ if(c4 || (fl & FmtSharp)){
+ n++;
+ }
+ if(chr == 'e' || chr == 'g'){
+ n += 4;
+ if(e >= 100)
+ n++;
+ }
+
+ /*
+ * pad to width if right justified
+ */
+ if((fl & (FmtWidth|FmtLeft)) == FmtWidth && n < fmt->width){
+ if(fl & FmtZero){
+ c1 += fmt->width - n;
+ }else{
+ if(__fmtpad(fmt, fmt->width - n) < 0){
+ return -1;
+ }
+ }
+ }
+
+ /*
+ * sign
+ */
+ d = 0;
+ if(sign)
+ d = '-';
+ else if(fl & FmtSign)
+ d = '+';
+ else if(fl & FmtSpace)
+ d = ' ';
+ if(d && fmtrune(fmt, d) < 0){
+ return -1;
+ }
+
+ /*
+ * copy digits
+ */
+ c4 = c1 + c2 + c3 - c4;
+ if(c1 > 0){
+ if(fmtzdotpad(fmt, c1, c4) < 0){
+ return -1;
+ }
+ c4 -= c1;
+ }
+ d = 0;
+ if(c4 >= 0 && c4 < c2){
+ if(__fmtcpy(fmt, s1, c4, c4) < 0 || fmtrune(fmt, '.') < 0)
+ return -1;
+ d = c4;
+ c2 -= c4;
+ c4 = -1;
+ }
+ if(__fmtcpy(fmt, (const void*)(s1 + d), c2, c2) < 0){
+ return -1;
+ }
+ c4 -= c2;
+ if(c3 > 0){
+ if(fmtzdotpad(fmt, c3, c4) < 0){
+ return -1;
+ }
+ c4 -= c3;
+ }
+
+ /*
+ * strip trailing '0' on g conv
+ */
+ if((fl & FmtSharp) && c4 == 0 && fmtrune(fmt, '.') < 0){
+ return -1;
+ }
+ if(chr == 'e' || chr == 'g') {
+ d = 0;
+ if(ucase)
+ s1[d++] = 'E';
+ else
+ s1[d++] = 'e';
+ c1 = e;
+ if(c1 < 0) {
+ s1[d++] = '-';
+ c1 = -c1;
+ } else
+ s1[d++] = '+';
+ if(c1 >= 100) {
+ s1[d++] = c1/100 + '0';
+ c1 = c1%100;
+ }
+ s1[d++] = c1/10 + '0';
+ s1[d++] = c1%10 + '0';
+ if(__fmtcpy(fmt, s1, d, d) < 0){
+ return -1;
+ }
+ }
+ if((fl & (FmtWidth|FmtLeft)) == (FmtWidth|FmtLeft) && n < fmt->width){
+ if(__fmtpad(fmt, fmt->width - n) < 0){
+ return -1;
+ }
+ }
+ return 0;
+}
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