lib/gnu/ieee_float/fphook.c

   1 /*
   2  * fltpr.c - print floating point numbers
   3  */
   4 /* $Header$ */
   5
   6 #ifndef NOFLOAT
   7 #include        <string.h>
   8 #include        <stdarg.h>
   9 #include        "../stdio/loc_incl.h"
  10 int _fp_hook = 1;
  11
  12 static char *
  13 _pfloat(long double r, register char *s, int n, int flags)
  14 {
  15         register char *s1;
  16         int sign, dp;
  17         register int i;
  18
  19         s1 = _fcvt(r, n, &dp, &sign);
  20         if (sign)
  21                 *s++ = '-';
  22         else if (flags & FL_SIGN)
  23                 *s++ = '+';
  24         else if (flags & FL_SPACE)
  25                 *s++ = ' ';
  26
  27         if (dp<=0)
  28                 *s++ = '0';
  29         for (i=dp; i>0; i--)
  30                 if (*s1) *s++ = *s1++;
  31                 else *s++ = '0';
  32         if (((i=n) > 0) || (flags & FL_ALT))
  33                 *s++ = '.';
  34         while (++dp <= 0) {
  35                 if (--i<0)
  36                         break;
  37                 *s++ = '0';
  38         }
  39         while (--i >= 0)
  40                 if (*s1) *s++ = *s1++;
  41                 else *s++ = '0';
  42         return s;
  43 }
  44
  45 static char *
  46 _pscien(long double r, register char *s, int n, int flags)
  47 {
  48         int sign, dp;
  49         register char *s1;
  50
  51         s1 = _ecvt(r, n + 1, &dp, &sign);
  52         if (sign)
  53                 *s++ = '-';
  54         else if (flags & FL_SIGN)
  55                 *s++ = '+';
  56         else if (flags & FL_SPACE)
  57                 *s++ = ' ';
  58
  59         *s++ = *s1++;
  60         if ((n > 0) || (flags & FL_ALT))
  61                 *s++ = '.';
  62         while (--n >= 0)
  63                 if (*s1) *s++ = *s1++;
  64                 else *s++ = '0';
  65         *s++ = 'e';
  66         if ( r != 0 ) --dp ;
  67         if ( dp<0 ) {
  68                 *s++ = '-' ; dp= -dp ;
  69         } else {
  70                 *s++ = '+' ;
  71         }
  72         if (dp >= 100) {
  73                 *s++ = '0' + (dp / 100);
  74                 dp %= 100;
  75         }
  76         *s++ = '0' + (dp/10);
  77         *s++ = '0' + (dp%10);
  78         return s;
  79 }
  80
  81 #define NDIGINEXP(exp)          (((exp) >= 100 || (exp) <= -100) ? 3 : 2)
  82 #define LOW_EXP                 -4
  83 #define USE_EXP(exp, ndigits)   (((exp) < LOW_EXP + 1) || (exp >= ndigits + 1))
  84
  85 static char *
  86 _gcvt(long double value, int ndigit, char *s, int flags)
  87 {
  88         int sign, dp;
  89         register char *s1, *s2;
  90         register int i;
  91         register int nndigit = ndigit;
  92
  93         s1 = _ecvt(value, ndigit, &dp, &sign);
  94         s2 = s;
  95         if (sign) *s2++ = '-';
  96         else if (flags & FL_SIGN)
  97                 *s2++ = '+';
  98         else if (flags & FL_SPACE)
  99                 *s2++ = ' ';
 100
 101         if (!(flags & FL_ALT))
 102                 for (i = nndigit - 1; i > 0 && s1[i] == '0'; i--)
 103                         nndigit--;
 104
 105         if (USE_EXP(dp,ndigit)) {
 106                 /* Use E format */
 107                 dp--;
 108                 *s2++ = *s1++;
 109                 if ((nndigit > 1) || (flags & FL_ALT)) *s2++ = '.';
 110                 while (--nndigit > 0) *s2++ = *s1++;
 111                 *s2++ = 'e';
 112                 if (dp < 0) {
 113                         *s2++ = '-';
 114                         dp = -dp;
 115                 }
 116                 else     *s2++ = '+';
 117                 s2 += NDIGINEXP(dp);
 118                 *s2 = 0;
 119                 for (i = NDIGINEXP(dp); i > 0; i--) {
 120                         *--s2 = dp % 10 + '0';
 121                         dp /= 10;
 122                 }
 123                 return s;
 124         }
 125         /* Use f format */
 126         if (dp <= 0) {
 127                 if (*s1 != '0') {
 128                         /* otherwise the whole number is 0 */
 129                         *s2++ = '0';
 130                         *s2++ = '.';
 131                 }
 132                 while (dp < 0) {
 133                         dp++;
 134                         *s2++ = '0';
 135                 }
 136         }
 137         for (i = 1; i <= nndigit; i++) {
 138                 *s2++ = *s1++;
 139                 if (i == dp) *s2++ = '.';
 140         }
 141         if (i <= dp) {
 142                 while (i++ <= dp) *s2++ = '0';
 143                 *s2++ = '.';
 144         }
 145         if ((s2[-1]=='.') && !(flags & FL_ALT)) s2--;
 146         *s2 = '\0';
 147         return s;
 148 }
 149
 150 char *
 151 _f_print(va_list *ap, int flags, char *s, char c, int precision)
 152 {
 153         register char *old_s = s;
 154         long double ld_val;
 155
 156         if (flags & FL_LONGDOUBLE) ld_val = va_arg(*ap, long double);
 157         else ld_val = (long double) va_arg(*ap, double);
 158
 159         switch(c) {
 160         case 'f':
 161                 s = _pfloat(ld_val, s, precision, flags);
 162                 break;
 163         case 'e':
 164         case 'E':
 165                 s = _pscien(ld_val, s, precision , flags);
 166                 break;
 167         case 'g':
 168         case 'G':
 169                 s = _gcvt(ld_val, precision, s, flags);
 170                 s += strlen(s);
 171                 break;
 172         }
 173         if ( c == 'E' || c == 'G') {
 174                 while (*old_s && *old_s != 'e') old_s++;
 175                 if (*old_s == 'e') *old_s = 'E';
 176         }
 177         return s;
 178 }
 179 #endif  /* NOFLOAT */
 180 /* $Header$ */
 181
 182 #include <stdlib.h>
 183 #include "../ansi/ext_fmt.h"
 184
 185 void _str_ext_cvt(const char *s, char **ss, struct EXTEND *e);
 186 double _ext_dbl_cvt(struct EXTEND *e);
 187
 188 double
 189 strtod(const char *p, char **pp)
 190 {
 191         struct EXTEND e;
 192
 193         _str_ext_cvt(p, pp, &e);
 194         return _ext_dbl_cvt(&e);
 195 }