kolibrios/programs/develop/libraries/newlib/math/s_roundf.c
Sergey Semyonov (Serge) 2336060a0c newlib: update
git-svn-id: svn://kolibrios.org@1906 a494cfbc-eb01-0410-851d-a64ba20cac60
2011-03-11 18:52:24 +00:00

71 lines
1.7 KiB
C

/* Round float to integer away from zero.
Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU 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 for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <math.h>
#include "fdlibm.h"
static const float huge = 1.0e30;
float roundf (float x)
{
int i0, j0;
GET_FLOAT_WORD (i0, x);
j0 = ((i0 >> 23) & 0xff) - 0x7f;
if (j0 < 23)
{
if (j0 < 0)
{
if (huge + x > 0.0F)
{
i0 &= 0x80000000;
if (j0 == -1)
i0 |= 0x3f800000;
}
}
else
{
unsigned int i = 0x007fffff >> j0;
if ((i0 & i) == 0)
/* X is integral. */
return x;
if (huge + x > 0.0F)
{
/* Raise inexact if x != 0. */
i0 += 0x00400000 >> j0;
i0 &= ~i;
}
}
}
else
{
if (j0 == 0x80)
/* Inf or NaN. */
return x + x;
else
return x;
}
SET_FLOAT_WORD (x, i0);
return x;
}