ack/lang/cem/libcc.ansi/sys/stdio/fltpr.c
2018-06-23 18:54:40 +02:00

213 lines
3.3 KiB
C

/*
* fltpr.c - print floating point numbers
*/
/* $Id$ */
#include <string.h>
#include <stdarg.h>
#include "loc_incl.h"
#if ACKCONF_WANT_STDIO && ACKCONF_WANT_STDIO_FLOAT
static char*
_pfloat(long double r, register char* s, int n, int flags)
{
register char* s1;
int sign, dp;
register int i;
s1 = _fcvt(r, n, &dp, &sign);
if (sign)
*s++ = '-';
else if (flags & FL_SIGN)
*s++ = '+';
else if (flags & FL_SPACE)
*s++ = ' ';
if (dp <= 0)
*s++ = '0';
for (i = dp; i > 0; i--)
if (*s1)
*s++ = *s1++;
else
*s++ = '0';
if (((i = n) > 0) || (flags & FL_ALT))
*s++ = '.';
while (++dp <= 0)
{
if (--i < 0)
break;
*s++ = '0';
}
while (--i >= 0)
if (*s1)
*s++ = *s1++;
else
*s++ = '0';
return s;
}
static char*
_pscien(long double r, register char* s, int n, int flags)
{
int sign, dp;
register char* s1;
s1 = _ecvt(r, n + 1, &dp, &sign);
if (sign)
*s++ = '-';
else if (flags & FL_SIGN)
*s++ = '+';
else if (flags & FL_SPACE)
*s++ = ' ';
*s++ = *s1++;
if ((n > 0) || (flags & FL_ALT))
*s++ = '.';
while (--n >= 0)
if (*s1)
*s++ = *s1++;
else
*s++ = '0';
*s++ = 'e';
if (r != 0)
--dp;
if (dp < 0)
{
*s++ = '-';
dp = -dp;
}
else
{
*s++ = '+';
}
if (dp >= 100)
{
*s++ = '0' + (dp / 100);
dp %= 100;
}
*s++ = '0' + (dp / 10);
*s++ = '0' + (dp % 10);
return s;
}
#define NDIGINEXP(exp) (((exp) >= 100 || (exp) <= -100) ? 3 : 2)
#define LOW_EXP -4
#define USE_EXP(exp, ndigits) (((exp) < LOW_EXP + 1) || (exp >= ndigits + 1))
static char*
_gcvt(long double value, int ndigit, char* s, int flags)
{
int sign, dp;
register char *s1, *s2;
register int i;
register int nndigit = ndigit;
s1 = _ecvt(value, ndigit, &dp, &sign);
s2 = s;
if (sign)
*s2++ = '-';
else if (flags & FL_SIGN)
*s2++ = '+';
else if (flags & FL_SPACE)
*s2++ = ' ';
if (!(flags & FL_ALT))
for (i = nndigit - 1; i > 0 && s1[i] == '0'; i--)
nndigit--;
if (USE_EXP(dp, ndigit))
{
/* Use E format */
dp--;
*s2++ = *s1++;
if ((nndigit > 1) || (flags & FL_ALT))
*s2++ = '.';
while (--nndigit > 0)
*s2++ = *s1++;
*s2++ = 'e';
if (dp < 0)
{
*s2++ = '-';
dp = -dp;
}
else
*s2++ = '+';
s2 += NDIGINEXP(dp);
*s2 = 0;
for (i = NDIGINEXP(dp); i > 0; i--)
{
*--s2 = dp % 10 + '0';
dp /= 10;
}
return s;
}
/* Use f format */
if (dp <= 0)
{
if (*s1 != '0')
{
/* otherwise the whole number is 0 */
*s2++ = '0';
*s2++ = '.';
}
while (dp < 0)
{
dp++;
*s2++ = '0';
}
}
for (i = 1; i <= nndigit; i++)
{
*s2++ = *s1++;
if (i == dp)
*s2++ = '.';
}
if (i <= dp)
{
while (i++ <= dp)
*s2++ = '0';
*s2++ = '.';
}
if ((s2[-1] == '.') && !(flags & FL_ALT))
s2--;
*s2 = '\0';
return s;
}
char* _f_print(va_list* ap, int flags, char* s, char c, int precision)
{
register char* old_s = s;
long double ld_val;
if (flags & FL_LONGDOUBLE)
ld_val = va_arg(*ap, long double);
else
ld_val = (long double)va_arg(*ap, double);
switch (c)
{
case 'f':
s = _pfloat(ld_val, s, precision, flags);
break;
case 'e':
case 'E':
s = _pscien(ld_val, s, precision, flags);
break;
case 'g':
case 'G':
s = _gcvt(ld_val, precision, s, flags);
s += strlen(s);
break;
}
if (c == 'E' || c == 'G')
{
while (*old_s && *old_s != 'e')
old_s++;
if (*old_s == 'e')
*old_s = 'E';
}
return s;
}
#endif