gen/common/gconvert.c

	gconvert.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Copyright (c) 1988 by Sun Microsystems, Inc.
 */

/*
 * gcvt  - Floating output conversion to minimal length string
 */

#include "base_conversion.h"
#ifndef PRE41
#include <locale.h>
#endif

void
_gcvt(ndigit, pd, trailing, buf)
    int             ndigit;
    decimal_record *pd;
    char           *buf;
{
    char           *p, *pstring;
    int             i;
    static char     *inf8 = "Infinity";
    static char     *inf3 = "Inf";
    static char     *nan = "NaN";
#ifdef PRE41
    char decpt = '.';
#else
    char decpt = *(localeconv()->decimal_point);
#endif

    p = buf;
    if (pd->sign)
        *(p++) = '-';
    switch (pd->fpclass) {
    case fp_zero:
        *(p++) = '0';
        if (trailing != 0) {
            *(p++) = decpt;
            for (i = 0; i < ndigit - 1; i++)
                *(p++) = '0';
        }
        break;
    case fp_infinity:
        if (ndigit < 8)
            pstring = inf3;
        else
            pstring = inf8;
        goto copystring;
    case fp_quiet:
    case fp_signaling:
        pstring = nan;
copystring:
        for (i = 0; *pstring != 0;)
            *(p++) = *(pstring++);
        break;
    default:
        if ((pd->exponent > 0) || (pd->exponent < -(ndigit + 3))) { /* E format. */
            char            estring[4];
            int             n;

            i = 0;
            *(p++) = pd->ds[0];
            *(p++) = decpt;
            for (i = 1; pd->ds[i] != 0;)
                *(p++) = pd->ds[i++];
            if (trailing == 0) {    /* Remove trailing zeros and . */
                p--;
                while (*p == '0')
                    p--;
                if (*p != decpt)
                    p++;
            }
            *(p++) = 'e';
            n = pd->exponent + i - 1;
            if (n >= 0)
                *(p++) = '+';
            else {
                *(p++) = '-';
                n = -n;
            }
            _fourdigitsquick((short unsigned) n, estring);
            for (i = 0; estring[i] == '0'; i++);    /* Find end of zeros. */
            if (i > 2)
                i = 2;  /* Guarantee two zeros. */
            for (; i <= 3;)
                *(p++) = estring[i++];  /* Copy exp digits. */
        } else {    /* F format. */
            if (pd->exponent >= (1 - ndigit)) { /* x.xxx */
                for (i = 0; i < (ndigit + pd->exponent);)
                    *(p++) = pd->ds[i++];
                *(p++) = decpt;
                if (pd->ds[i] != 0) {   /* More follows point. */
                    for (; i < ndigit;)
                        *(p++) = pd->ds[i++];
                }
            } else {/* 0.00xxxx */
                *(p++) = '0';
                *(p++) = decpt;
                for (i = 0; i < -(pd->exponent + ndigit); i++)
                    *(p++) = '0';
                for (i = 0; pd->ds[i] != 0;)
                    *(p++) = pd->ds[i++];
            }
            if (trailing == 0) {    /* Remove trailing zeros and point. */
                p--;
                while (*p == '0')
                    p--;
                if (*p != decpt)
                    p++;
            }
        }
    }
    *(p++) = 0;
}

char           *
gconvert(number, ndigit, trailing, buf)
    double          number;
    int             ndigit, trailing;
    char           *buf;
{
    decimal_mode    dm;
    decimal_record  dr;
    fp_exception_field_type fef;

    dm.rd = fp_direction;
    dm.df = floating_form;
    dm.ndigits = ndigit;
    double_to_decimal(&number, &dm, &dr, &fef);
    _gcvt(ndigit, &dr, trailing, buf);
    return (buf);
}

char           *
gcvt(number, ndigit, buf)
    double          number;
    int             ndigit;
    char           *buf;
{
    return (gconvert(number, ndigit, 0, buf));
}