glibc/sysdeps/libm-ieee754/s_roundl.c
Ulrich Drepper dd33e89fb2 Update.
1997-04-17 16:55  Ulrich Drepper  <drepper@cygnus.com>

	* misc/libgen.h: Change prototype for of basename to XPG variant.
	* stdlib/Makefile (routines): Add xpg_basename.
	* stdlib/basename.c: New file.
	* string/string.h: Don't declare basename function if basename
	macro is available.

1997-04-16 17:33  Miles Bader  <miles@gnu.ai.mit.edu>

	* login/utmp_file.c (proc_utmp_eq): Only use ut_id field if valid.

1997-04-15 12:47  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/m68k/fpu/fclrexcpt.c: New file.
	* sysdeps/m68k/fpu/fenvbits.h: New file.
	* sysdeps/m68k/fpu/fegetenv.c: New file.
	* sysdeps/m68k/fpu/fegetround.c: New file.
	* sysdeps/m68k/fpu/fesetenv.c: New file.
	* sysdeps/m68k/fpu/fesetround.c: New file.
	* sysdeps/m68k/fpu/feupdateenv.c: New file.
	* sysdeps/m68k/fpu/fgetexcptflg.c: New file.
	* sysdeps/m68k/fpu/fraiseexcpt.c: New file.
	* sysdeps/m68k/fpu/fsetexcptflg.c: New file.
	* sysdeps/m68k/fpu/ftestexcept.c: New file.
	* sysdeps/m68k/fpu/mathbits.h: New file.

	* sysdeps/m68k/fpu/s_remquo.c: New file.
	* sysdeps/m68k/fpu/s_remquol.c: New file.
	* sysdeps/m68k/fpu/s_remquof.c: New file.

	* sysdeps/libm-ieee754/s_roundl.c: Restore integer bit when
	mantissa overflows into exponent.  Fix priority of >> vs +.

	* math/libm-test.c (basic_tests): Use the appropriate isnan and
	isinf function to test the value of the nan function.

1997-04-15 13:40  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/libm-i387/s_finite.S: Fix typo.

	* sysdeps/i386/fpu/__math.h: Add optimized versions of isgreater,
	isgreaterequal, isless, islessequal, islessgreater, and
	isunordered.
1997-04-17 15:10:04 +00:00

107 lines
2.3 KiB
C

/* Round long double 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <math.h>
#include "math_private.h"
static const long double huge = 1.0e4930;
long double
__roundl (long double x)
{
int32_t j0;
u_int32_t se, i1, i0;
GET_LDOUBLE_WORDS (se, i0, i1, x);
j0 = (se & 0x7fff) - 0x3fff;
if (j0 < 31)
{
if (j0 < 0)
{
if (huge + x > 0.0)
{
se &= 0x8000;
i0 = i1 = 0;
if (j0 == -1)
{
se |= 0x3fff;
i0 = 0x80000000;
}
}
}
else
{
u_int32_t i = 0x7fffffff >> j0;
if (((i0 & i) | i1) == 0)
/* X is integral. */
return x;
if (huge + x > 0.0)
{
/* Raise inexact if x != 0. */
u_int32_t j = i0 + (0x40000000 >> j0);
if (j < i0)
se += 1;
i0 = (j & ~i) | 0x80000000;
i1 = 0;
}
}
}
else if (j0 > 62)
{
if (j0 == 0x4000)
/* Inf or NaN. */
return x + x;
else
return x;
}
else
{
u_int32_t i = 0xffffffff >> (j0 - 31);
if ((i1 & i) == 0)
/* X is integral. */
return x;
if (huge + x > 0.0)
{
/* Raise inexact if x != 0. */
u_int32_t j = i1 + (1 << (62 - j0));
if (j < i1)
{
u_int32_t k = i0 + 1;
if (k < i0)
{
se += 1;
k |= 0x80000000;
}
i0 = k;
}
i1 = j;
}
i1 &= ~i;
}
SET_LDOUBLE_WORDS (x, se, i0, i1);
return x;
}
weak_alias (__roundl, roundl)