glibc/sysdeps/alpha/fpu/s_round.c
2012-03-09 23:56:38 +00:00

49 lines
1.4 KiB
C

/* Copyright (C) 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_ldbl_opt.h>
double
__round (double x)
{
const double almost_half = 0x1.fffffffffffffp-2;
const double two52 = 0x1.0p52;
double tmp, r;
__asm (
#ifdef _IEEE_FP_INEXACT
"addt/suic %2, %3, %1\n\tsubt/suic %1, %3, %0"
#else
"addt/suc %2, %3, %1\n\tsubt/suc %1, %3, %0"
#endif
: "=&f"(r), "=&f"(tmp)
: "f"(fabs (x) + almost_half), "f"(two52));
return copysign (r, x);
}
weak_alias (__round, round)
#ifdef NO_LONG_DOUBLE
strong_alias (__round, __roundl)
weak_alias (__roundl, roundl)
#endif
#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_1)
compat_symbol (libm, __round, roundl, GLIBC_2_1);
#endif