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/* Returns the _Decimal32 value * 2^ the integral value
Copyright (C) 2006 IBM Corporation.
Copyright (C) 2007-2015 Free Software Foundation, Inc.
This file is part of the Decimal Floating Point C Library.
Author(s): Joseph Kerian <jkerian@us.ibm.com>
The Decimal Floating Point C Library is free software; you can
redistribute it and/or modify it under the terms of the GNU Lesser
General Public License version 2.1.
The Decimal Floating Point C Library 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 Lesser General Public License version 2.1 for more details.
You should have received a copy of the GNU Lesser General Public
License version 2.1 along with the Decimal Floating Point C Library;
if not, write to the Free Software Foundation, Inc., 59 Temple Place,
Suite 330, Boston, MA 02111-1307 USA.
Please see libdfp/COPYING.txt for more information. */
#ifndef _DECIMAL_SIZE
# include <decimal32.h>
# define _DECIMAL_SIZE 32
#endif
#include <decContext.h>
#include <decNumber.h>
#include <math.h>
#include <errno.h>
#include <ieee754r_private.h>
#define FUNCTION_NAME ldexp
#include <dfpmacro.h>
#include <numdigits.h>
#include <limits.h>
static DEC_TYPE
IEEE_FUNCTION_NAME (DEC_TYPE x, int y)
{
DEC_TYPE result;
long newexp;
#if NUMDIGITS_SUPPORT==1
newexp = FUNC_D (getexp) (x) + y + 1;
if (newexp > PASTE(DECIMAL,PASTE(_DECIMAL_SIZE,_Emax)))
{
result = DFP_HUGE_VAL;
DFP_EXCEPT (FE_OVERFLOW);
}
else if (newexp < PASTE(DECIMAL,PASTE(_DECIMAL_SIZE,_Emin)))
{
result = -DFP_HUGE_VAL;
DFP_EXCEPT (FE_OVERFLOW);
}
else
result = FUNC_D(setexp) (x, newexp);
#else
decContext context;
decNumber dn_x;
FUNC_CONVERT_TO_DN (&x, &dn_x);
if (___decNumberIsNaN (&dn_x) || ___decNumberIsZero (&dn_x) ||
___decNumberIsInfinite (&dn_x))
return x+x;
if (y == 0)
return x;
/* ldexp(x,y) is just x*10**y, which is equivalent to increasing the exponent
* by y + 1. */
newexp = dn_x.exponent + y + 1;
if(newexp > INT_MAX)
newexp = INT_MAX;
if(newexp < -INT_MAX)
newexp = -INT_MAX;
dn_x.exponent = newexp;
decContextDefault (&context, DEFAULT_CONTEXT);
FUNC_CONVERT_FROM_DN (&dn_x, &result, &context);
if (context.status & DEC_Overflow)
DFP_EXCEPT (FE_OVERFLOW);
#endif
return result;
}
DEC_TYPE
INTERNAL_FUNCTION_NAME (DEC_TYPE x, int y)
{
DEC_TYPE z = IEEE_FUNCTION_NAME (x, y);
if (!FUNC_D(__isfinite) (z) && FUNC_D(__isfinite) (x))
DFP_ERRNO (ERANGE);
return z;
}
weak_alias (INTERNAL_FUNCTION_NAME, EXTERNAL_FUNCTION_NAME)
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