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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_exp2.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_exp2.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_exp2.c b/Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_exp2.c new file mode 100644 index 00000000000..dd571d0ab96 --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_exp2.c @@ -0,0 +1,65 @@ +/* __gmpfr_ceil_exp2 - returns y >= 2^d + +Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. +Contributed by the AriC and Caramel projects, INRIA. + +This file is part of the GNU MPFR Library. + +The GNU MPFR Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Lesser General Public License as published by +the Free Software Foundation; either version 3 of the License, or (at your +option) any later version. + +The GNU MPFR 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 Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser General Public License +along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see +http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., +51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include "mpfr-impl.h" + +/* returns y >= 2^d, assuming that d <= 1024 + for d integer, returns exactly 2^d +*/ +double +__gmpfr_ceil_exp2 (double d) +{ + long exp; +#if _GMP_IEEE_FLOATS + union ieee_double_extract x; +#else + struct {double d;} x; +#endif + + MPFR_ASSERTN(d <= 1024.0); + exp = (long) d; + if (d != (double) exp) + exp++; + /* now exp = ceil(d) */ + x.d = 1.0; +#if _GMP_IEEE_FLOATS + x.s.exp = exp <= -1022 ? 1 : 1023 + exp; +#else + if (exp >= 0) + { + while (exp != 0) + { + x.d *= 2.0; + exp--; + } + } + else + { + while (exp != 0) + { + x.d *= (1.0 / 2.0); + exp++; + } + } +#endif + return x.d; +} |