diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_roundl.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_roundl.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_roundl.c b/sysdeps/libm-ieee754/s_roundl.c new file mode 100644 index 0000000000..db87154089 --- /dev/null +++ b/sysdeps/libm-ieee754/s_roundl.c @@ -0,0 +1,100 @@ +/* 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; + if (j0 == -1) + se |= 0x3fff; + i0 = i1 = 0; + } + } + 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; + i0 = k; + } + i1 = j; + } + i1 &= ~i; + } + + SET_LDOUBLE_WORDS (x, se, i0, i1); + return x; +} +weak_alias (__roundl, roundl) |