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b58ddff026
* merged mpfr 3.0.0 and gmp 5.0.1 in buildtools trunk git-svn-id: file:///srv/svn/repos/haiku/buildtools/trunk@37378 a95241bf-73f2-0310-859d-f6bbb57e9c96
47 lines
1.6 KiB
C
47 lines
1.6 KiB
C
/* mpfr_powerof2_raw -- test whether a floating-point number is a power of 2
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Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
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Contributed by the Arenaire and Cacao projects, INRIA.
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This file is part of the GNU MPFR Library.
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The GNU MPFR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 3 of the License, or (at your
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option) any later version.
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The GNU MPFR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
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http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
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51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
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#include "mpfr-impl.h"
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/* This is an internal function and one assumes that x is a real number. */
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int
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mpfr_powerof2_raw (mpfr_srcptr x)
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{
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mp_limb_t *xp;
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mp_size_t xn;
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/* This is an internal function, and we may call it with some
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wrong numbers (ie good mantissa but wrong flags or exp)
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So we don't want to test if it is a pure FP.
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MPFR_ASSERTN(MPFR_IS_PURE_FP(x)); */
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xp = MPFR_MANT(x);
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xn = (MPFR_PREC(x) - 1) / GMP_NUMB_BITS;
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/*if (NOT_POW2(xp[xn]))*/
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if (xp[xn] != MPFR_LIMB_HIGHBIT)
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return 0;
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while (xn > 0)
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if (xp[--xn] != 0)
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return 0;
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return 1;
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}
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