port/fp/gconvert.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include "lint.h"
#include "base_conversion.h"
#include <sys/types.h>
#include "libc.h"
#include <locale.h>

static void
__k_gconvert(int ndigits, decimal_record *pd, int trailing, char *buf)
{
    char    *p;
    int i;
    char    decpt = *(localeconv()->decimal_point);

    p = buf;
    if (pd->sign)
        *(p++) = '-';
    switch (pd->fpclass) {
    case fp_zero:
        *(p++) = '0';
        if (trailing != 0) {
            *(p++) = decpt;
            for (i = 0; i < ndigits - 1; i++)
                *(p++) = '0';
        }
        *p++ = 0;
        break;
    case fp_subnormal:
    case fp_normal:
        if ((pd->exponent > 0) || (pd->exponent < -(ndigits + 3))) {
            /* E format. */
            char    estring[4];
            int n;

            *(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;
            }
            __four_digits_quick((unsigned short) n, estring);

                /* Find end of zeros. */
            for (i = 0; estring[i] == '0'; i++)
                ;

            if (i > 2)
                i = 2;  /* Guarantee two zeros. */
            for (; i <= 3; )
                *(p++) = estring[i++];  /* Copy exp digits. */
        } else {    /* F format. */
            if (pd->exponent >= (1 - ndigits)) {    /* x.xxx */
                for (i = 0; i < (ndigits + pd->exponent); )
                    *(p++) = pd->ds[i++];
                *(p++) = decpt;
                if (pd->ds[i] != 0) {
                    /* More follows point. */
                    for (; i < ndigits; )
                        *(p++) = pd->ds[i++];
                }
            } else { /* 0.00xxxx */
                *(p++) = '0';
                *(p++) = decpt;
                for (i = 0; i < -(pd->exponent + ndigits); 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;
        break;
    default:
        __infnanstring(pd->fpclass, ndigits, p);
        break;
    }
}

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

#if defined(__sparc)
    dm.rd = _QgetRD();
#elif defined(__i386) || defined(__amd64)
    dm.rd = __xgetRD();
#else
#error Unknown architecture
#endif
    dm.df = floating_form;
    if (ndigits < 0)
        ndigits = 6;
    else if (ndigits == 0)
        ndigits = 1;
    else if (ndigits >= DECIMAL_STRING_LENGTH)
        ndigits = DECIMAL_STRING_LENGTH - 1;
    dm.ndigits = ndigits;
    double_to_decimal(&number, &dm, &dr, &fef);
    __k_gconvert(ndigits, &dr, trailing, buf);
    return (buf);
}

char *
sgconvert(single *number, int ndigits, int trailing, char *buf)
{
    decimal_mode    dm;
    decimal_record  dr;
    fp_exception_field_type fef;

#if defined(__sparc)
    dm.rd = _QgetRD();
#elif defined(__i386) || defined(__amd64)
    dm.rd = __xgetRD();
#else
#error Unknown architecture
#endif
    dm.df = floating_form;
    if (ndigits < 0)
        ndigits = 6;
    else if (ndigits == 0)
        ndigits = 1;
    else if (ndigits >= DECIMAL_STRING_LENGTH)
        ndigits = DECIMAL_STRING_LENGTH - 1;
    dm.ndigits = ndigits;
    single_to_decimal(number, &dm, &dr, &fef);
    __k_gconvert(ndigits, &dr, trailing, buf);
    return (buf);
}

char *
qgconvert(quadruple *number, int ndigits, int trailing, char *buf)
{
    decimal_mode    dm;
    decimal_record  dr;
    fp_exception_field_type fef;

#if defined(__sparc)
    dm.rd = _QgetRD();
#elif defined(__i386) || defined(__amd64)
    dm.rd = __xgetRD();
#else
#error Unknown architecture
#endif
    dm.df = floating_form;
    if (ndigits < 0)
        ndigits = 6;
    else if (ndigits == 0)
        ndigits = 1;
    else if (ndigits >= DECIMAL_STRING_LENGTH)
        ndigits = DECIMAL_STRING_LENGTH - 1;
    dm.ndigits = ndigits;
#if defined(__sparc)
    quadruple_to_decimal(number, &dm, &dr, &fef);
#elif defined(__i386) || defined(__amd64)
    extended_to_decimal((extended *)number, &dm, &dr, &fef);
#else
#error Unknown architecture
#endif
    __k_gconvert(ndigits, &dr, trailing, buf);
    return (buf);
}