diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_lrintf.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_lrintf.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_lrintf.c b/sysdeps/libm-ieee754/s_lrintf.c new file mode 100644 index 0000000000..6d74b362f5 --- /dev/null +++ b/sysdeps/libm-ieee754/s_lrintf.c @@ -0,0 +1,78 @@ +/* Round argument to nearest integral value according to current rounding + direction. + 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 double two23[2] = +{ + 8.3886080000e+06, /* 0x4B000000 */ + -8.3886080000e+06, /* 0xCB000000 */ +}; + + +long int +__lrintf (float x) +{ + int32_t j0; + u_int32_t i, i0; + volatile float w; + float t; + long int result; + int sx; + + GET_FLOAT_WORD (i, x); + + sx = i0 >> 31; + j0 = ((i0 >> 23) & 0xff) - 0x7f; + i0 = i & 0x7fffff; + i0 |= 0x800000; + + if (j0 < (int32_t) (sizeof (long int) * 8)) + { + if (j0 < -1) + return 0; + else if (j0 >= 23) + result = (long int) i0 << (j0 - 23); + else + { + w = two23[sx] + x; + t = w - two23[sx]; + GET_FLOAT_WORD (i, t); + i0 = i & 0x7fffff; + i0 |= 0x800000; + j0 = ((i0 >> 23) & 0xff) - 0x7f; + + result = i0 >> (23 - j0); + } + } + else + { + /* The number is too large. It is left implementation defined + what happens. */ + return (long int) x; + } + + return sx ? -result : result; +} + +weak_alias (__lrintf, lrintf) |