diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_trunc.c')
-rw-r--r-- | sysdeps/libm-ieee754/s_trunc.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_trunc.c b/sysdeps/libm-ieee754/s_trunc.c new file mode 100644 index 0000000000..721dce5a55 --- /dev/null +++ b/sysdeps/libm-ieee754/s_trunc.c @@ -0,0 +1,61 @@ +/* Truncate argument to nearest integral value not larger than the argument. + 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" + + +double +__trunc (double x) +{ + int32_t i0, j0; + u_int32_t i1; + int sx; + + EXTRACT_WORDS (i0, i1, x); + sx = i0 & 0x80000000; + j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; + if (j0 < 20) + { + if (j0 < 0) + /* The magnitude of the number is < 1 so the result is +-0. */ + INSERT_WORDS (x, sx, 0); + else + INSERT_WORDS (x, sx | i0 & ~(0x000fffff >> j0), 0); + } + else if (j0 > 51) + { + if (j0 == 0x400) + /* x is inf or NaN. */ + return x + x; + } + else + { + INSERT_WORDS (x, i0, i1 & ~(0xffffffffu >> (j0 - 20))); + } + + return x; +} +weak_alias (__trunc, trunc) +#ifdef NO_LONG_DOUBLE +strong_alias (__trunc, __truncl) +weak_alias (__trunc, truncl) +#endif |