diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128/s_roundl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128/s_roundl.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/s_roundl.c b/sysdeps/ieee754/ldbl-128/s_roundl.c new file mode 100644 index 0000000000..f9fff48f6c --- /dev/null +++ b/sysdeps/ieee754/ldbl-128/s_roundl.c @@ -0,0 +1,94 @@ +/* Round long double to integer away from zero. + Copyright (C) 1997, 1999 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and + Jakub Jelinek <jj@ultra.linux.cz>, 1999. + + 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 = 1.0E4930L; + + +long double +__roundl (long double x) +{ + int32_t j0; + u_int64_t se, i1, i0; + + GET_LDOUBLE_WORDS64 (i0, i1, x); + j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; + if (j0 < 31) + { + if (j0 < 0) + { + if (huge + x > 0.0) + { + i0 &= 0x8000000000000000ULL; + if (j0 == -1) + i0 |= 0x3fff000000000000LL; + i1 = 0; + } + } + else + { + u_int64_t i = 0x0000ffffffffffffLL >> j0; + if (((i0 & i) | i1) == 0) + /* X is integral. */ + return x; + if (huge + x > 0.0) + { + /* Raise inexact if x != 0. */ + i0 += 0x0000800000000000LL >> j0; + i0 &= ~i; + i1 = 0; + } + } + } + else if (j0 > 111) + { + if (j0 == 0x4000) + /* Inf or NaN. */ + return x + x; + else + return x; + } + else + { + u_int64_t i = -1ULL >> (j0 - 48); + if ((i1 & i) == 0) + /* X is integral. */ + return x; + + if (huge + x > 0.0) + { + /* Raise inexact if x != 0. */ + u_int64_t j = i1 + (1LL << (111 - j0)); + if (j < i1) + i0 += 1; + i1 = j; + } + i1 &= ~i; + } + + SET_LDOUBLE_WORDS64 (x, i0, i1); + return x; +} +weak_alias (__roundl, roundl) |