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-rw-r--r--Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_log2.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_log2.c b/Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_log2.c
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index 00000000000..27f7d4fc784
--- /dev/null
+++ b/Build/source/libs/mpfr/mpfr-3.1.2/src/uceil_log2.c
@@ -0,0 +1,63 @@
+/* __gmpfr_ceil_log2 - returns ceil(log(d)/log(2))
+
+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 ceil(log(d)/log(2)) if d > 0,
+ -1023 if d = +0,
+ and floor(log(-d)/log(2))+1 if d < 0*/
+long
+__gmpfr_ceil_log2 (double d)
+{
+ long exp;
+#if _GMP_IEEE_FLOATS
+ union ieee_double_extract x;
+
+ x.d = d;
+ exp = x.s.exp - 1023;
+ x.s.exp = 1023; /* value for 1 <= d < 2 */
+ if (x.d != 1.0) /* d: not a power of two? */
+ exp++;
+ return exp;
+#else
+ double m;
+
+ if (d < 0.0)
+ return __gmpfr_floor_log2(-d)+1;
+ else if (d == 0.0)
+ return -1023;
+ else if (d >= 1.0)
+ {
+ exp = 0;
+ for( m= 1.0 ; m < d ; m *=2.0 )
+ exp++;
+ }
+ else
+ {
+ exp = 1;
+ for( m= 1.0 ; m >= d ; m *= (1.0/2.0) )
+ exp--;
+ }
+#endif
+ return exp;
+}
+