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/* $OpenBSD: ldtoa.c,v 1.2 2014/08/10 02:15:18 guenther Exp $ */
/*-
* Copyright (c) 2003 David Schultz <das@FreeBSD.ORG>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#ifndef __vax__
#include <machine/ieee.h>
#endif /* !__vax__ */
#include <float.h>
#include <stdint.h>
#include <limits.h>
#include <math.h>
#include <stdlib.h>
#include "gdtoaimp.h"
#if (LDBL_MANT_DIG > DBL_MANT_DIG)
/*
* ldtoa() is a wrapper for gdtoa() that makes it smell like dtoa(),
* except that the floating point argument is passed by reference.
* When dtoa() is passed a NaN or infinity, it sets expt to 9999.
* However, a long double could have a valid exponent of 9999, so we
* use INT_MAX in ldtoa() instead.
*/
char *
__ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign,
char **rve)
{
FPI fpi = {
LDBL_MANT_DIG, /* nbits */
LDBL_MIN_EXP - LDBL_MANT_DIG, /* emin */
LDBL_MAX_EXP - LDBL_MANT_DIG, /* emax */
FLT_ROUNDS, /* rounding */
#ifdef Sudden_Underflow /* unused, but correct anyway */
1
#else
0
#endif
};
int be, kind;
char *ret;
struct ieee_ext *p = (struct ieee_ext *)ld;
uint32_t bits[(LDBL_MANT_DIG + 31) / 32];
void *vbits = bits;
/*
* gdtoa doesn't know anything about the sign of the number, so
* if the number is negative, we need to swap rounding modes of
* 2 (upwards) and 3 (downwards).
*/
*sign = p->ext_sign;
fpi.rounding ^= (fpi.rounding >> 1) & p->ext_sign;
be = p->ext_exp - (LDBL_MAX_EXP - 1) - (LDBL_MANT_DIG - 1);
EXT_TO_ARRAY32(p, bits);
switch (fpclassify(*ld)) {
case FP_NORMAL:
kind = STRTOG_Normal;
#ifdef EXT_IMPLICIT_NBIT
bits[LDBL_MANT_DIG / 32] |= 1 << ((LDBL_MANT_DIG - 1) % 32);
#endif /* EXT_IMPLICIT_NBIT */
break;
case FP_ZERO:
kind = STRTOG_Zero;
break;
case FP_SUBNORMAL:
kind = STRTOG_Denormal;
be++;
break;
case FP_INFINITE:
kind = STRTOG_Infinite;
break;
case FP_NAN:
kind = STRTOG_NaN;
break;
default:
abort();
}
ret = gdtoa(&fpi, be, vbits, &kind, mode, ndigits, decpt, rve);
if (*decpt == -32768)
*decpt = INT_MAX;
return ret;
}
#else /* (LDBL_MANT_DIG == DBL_MANT_DIG) */
char *
__ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign,
char **rve)
{
char *ret;
ret = dtoa((double)*ld, mode, ndigits, decpt, sign, rve);
if (*decpt == 9999)
*decpt = INT_MAX;
return ret;
}
#endif /* (LDBL_MANT_DIG == DBL_MANT_DIG) */
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