InterCD 2000 September/september_2000.iso/intercd/root/^Linux/cdrecord-1.8.1/lib/fconv.c

C/C++ Source or Header | 2000-04-21 | 5.1 KB | 252 lines

/* @(#)fconv.c    1.27 00/04/21 Copyright 1985 J. Schilling */
/*
 *    Convert floating point numbers to strings for format.c
 *    Should rather use the MT-safe routines [efg]convert()
 *
 *    Copyright (c) 1985 J. Schilling
 */
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <mconfig.h>    /* <- may define NO_FLOATINGPOINT */
#ifndef    NO_FLOATINGPOINT

#include <stdxlib.h>
#include <standard.h>
#include <strdefs.h>

#if    !defined(HAVE_STDLIB_H) || defined(HAVE_DTOA)
extern    char    *ecvt __PR((double, int, int *, int *));
extern    char    *fcvt __PR((double, int, int *, int *));
#endif

#if    defined(HAVE_ISNAN) && defined(HAVE_ISINF)
#define    FOUND_ISXX
#endif

#include <math.h>

#if    defined(HAVE_IEEEFP_H) && !defined(FOUND_ISXX)
/*
 * SVR4
 */
#include <ieeefp.h>
#define    isnan    isnand
#define    isinf    !finite
#define    FOUND_ISXX
#endif

#if    defined(HAVE_FP_H)  && !defined(FOUND_ISXX)
/*
 * WAS:
 * #if    defined(__osf__) || defined(_IBMR2) || defined(_AIX)
 */
#include <fp.h>
#ifndef    isnan
#define    isnan    IS_NAN
#endif
#ifndef    isinf
#define    isinf    !FINITE
/*#define    isinf    IS_INF*/
#endif
#define    FOUND_ISXX
#endif

/*
 * WAS:
 * #if    defined(__hpux) || defined(VMS) || defined(_SCO_DS) || defined(__QNX__)
 */
#if    defined(__hpux)
#undef    isnan
#undef    isinf
#endif

#if    !defined(isnan) && !defined(HAVE_ISNAN)
#define    isnan(val)    (0)
#endif
#if    !defined(isinf) && !defined(HAVE_ISINF)
#define    isinf(val)    (0)
#endif

#if !defined(HAVE_ECVT) || !defined(HAVE_FCVT) || !defined(HAVE_GCVT)
#include "cvt.c"
#endif

static    char    _nan[] = "(NaN)";
static    char    _inf[] = "(Infinity)";

static    int    _ferr __PR((char *, double));

#ifdef    abs
#    undef    abs
#endif
#define    abs(i)    ((i) < 0 ? -(i) : (i))

EXPORT int
ftoes(s, val, fieldwidth, ndigits)
    register    char     *s;
            double    val;
    register    int    fieldwidth;
    register    int    ndigits;
{
    register    char    *b;
    register    char    *rs;
    register    int    len;
    register    int    rdecpt;
            int     decpt;
            int    sign;

    if ((len = _ferr(s, val)) > 0)
        return len;
    rs = s;
#ifdef    V7_FLOATSTYLE
    b = ecvt(val, ndigits, &decpt, &sign);
    rdecpt = decpt;
#else
    b = ecvt(val, ndigits+1, &decpt, &sign);
    rdecpt = decpt-1;
#endif
    len = ndigits + 6;            /* Punkt e +/- nnn */
    if (sign)
        len++;
    if (fieldwidth > len)
        while (fieldwidth-- > len)
            *rs++ = ' ';
    if (sign)
        *rs++ = '-';
#ifndef    V7_FLOATSTYLE
    if (*b)
        *rs++ = *b++;
#endif
    *rs++ = '.';
    while (*b && ndigits-- > 0)
        *rs++ = *b++;
    *rs++ = 'e';
    *rs++ = rdecpt >= 0 ? '+' : '-';
    rdecpt = abs(rdecpt);
#ifndef    V7_FLOATSTYLE
    if (rdecpt >= 100)
#endif
    {
        *rs++ = rdecpt / 100 + '0';
        rdecpt %= 100;
    }
    *rs++ = rdecpt / 10 + '0';
    *rs++ = rdecpt % 10 + '0';
    *rs = '\0';
    return rs - s;
}

/*
 * fcvt() from Cygwin32 is buggy.
 */
#if    !defined(HAVE_FCVT) && defined(HAVE_ECVT)
#define    USE_ECVT
#endif

EXPORT int
ftofs(s, val, fieldwidth, ndigits)
    register    char     *s;
            double    val;
    register    int    fieldwidth;
    register    int    ndigits;
{
    register    char    *b;
    register    char    *rs;
    register    int    len;
    register    int    rdecpt;
            int     decpt;
            int    sign;

    if ((len = _ferr(s, val)) > 0)
        return len;
    rs = s;
#ifdef    USE_ECVT
    /*
     * Needed on systems with broken fcvt() implementation
     * (e.g. Cygwin32)
     */
    b = ecvt(val, ndigits, &decpt, &sign);
    /*
     * The next call is needed to force higher precision.
     */
    if (decpt > 0)
        b = ecvt(val, ndigits+decpt, &decpt, &sign);
#else
    b = fcvt(val, ndigits, &decpt, &sign);
#endif
    rdecpt = decpt;
    len = rdecpt + ndigits + 1;
    if (rdecpt < 0)
        len -= rdecpt;
    if (sign)
        len++;
    if (fieldwidth > len)
        while (fieldwidth-- > len)
            *rs++ = ' ';
    if (sign)
        *rs++ = '-';
    if (rdecpt > 0) {
        len = rdecpt;
        while (*b && len-- > 0)
            *rs++ = *b++;
#ifdef    USE_ECVT
        while (len-- > 0)
            *rs++ = '0';
#endif
    }
#ifndef    V7_FLOATSTYLE
    else {
        *rs++ = '0';
    }
#endif
    *rs++ = '.';
    if (rdecpt < 0) {
        len = rdecpt;
        while (len++ < 0 && ndigits-- > 0)
            *rs++ = '0';
    }
    while (*b && ndigits-- > 0)
        *rs++ = *b++;
#ifdef    USE_ECVT
    while (ndigits-- > 0)
        *rs++ = '0';
#endif
    *rs = '\0';
    return rs - s;
}

LOCAL int
_ferr(s, val)
    char    *s;
    double    val;
{
    if (isnan(val)){
        strcpy(s, _nan);
        return (sizeof (_nan) - 1);
    }

    /*
     * Check first for NaN because finite() will return 1 on Nan too.
     */
    if (isinf(val)){
        strcpy(s, _inf);
        return (sizeof (_inf) - 1);
    }
    return 0;
}
#endif    /* NO_FLOATINGPOINT */