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git-svn-id: file:///srv/svn/repos/haiku/buildtools/trunk@29042 a95241bf-73f2-0310-859d-f6bbb57e9c96
52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
/* __gmpfr_isqrt && __gmpfr_cuberoot -- Integer square root and cube root
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Copyright 2004, 2005, 2006, 2007 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 MPFR Library.
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The 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 2.1 of the License, or (at your
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option) any later version.
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The 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 MPFR Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include "mpfr-impl.h"
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/* returns floor(sqrt(n)) */
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unsigned long
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__gmpfr_isqrt (unsigned long n)
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{
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unsigned long s;
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s = 1;
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do {
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s = (s + n / s) / 2;
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} while (!(s*s <= n && n <= s*(s+2)));
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return s;
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}
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/* returns floor(n^(1/3)) */
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unsigned long
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__gmpfr_cuberoot (unsigned long n)
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{
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double s, is;
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s = 1.0;
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do {
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s = (2*s*s*s + (double) n) / (3*s*s);
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is = (double) ((int) s);
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} while (!(is*is*is <= (double) n && (double) n < (is+1)*(is+1)*(is+1)));
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return (unsigned long) is;
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}
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