diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_roundf.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_roundf.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_roundf.c b/sysdeps/libm-ieee754/s_roundf.c new file mode 100644 index 0000000000..5dc0e368ff --- /dev/null +++ b/sysdeps/libm-ieee754/s_roundf.c @@ -0,0 +1,73 @@ +/* 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 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 float huge = 1.0e30; + + +float +__roundf (float x) +{ + int32_t 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 + { + u_int32_t 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; +} +weak_alias (__roundf, roundf) |