mirror of https://github.com/macssh/macssh.git
68 lines
1.9 KiB
C
68 lines
1.9 KiB
C
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/* mpfr_pow_ui, mpfr_ui_pow_ui -- compute the power of a floating-point
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number or machine integer
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Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
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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 Library General Public License as published by
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the Free Software Foundation; either version 2 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 Library General Public
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License for more details.
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You should have received a copy of the GNU Library 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., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA. */
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#include <stdio.h>
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#include "gmp.h"
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#include "mpfr.h"
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/* sets x to y^n */
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void
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#if __STDC__
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mpfr_pow_ui (mpfr_ptr x, mpfr_srcptr y, unsigned int n, unsigned char rnd)
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#else
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mpfr_pow_ui (x, y, n, rnd)
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mpfr_ptr x;
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mpfr_srcptr y;
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unsigned int n;
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unsigned char rnd;
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#endif
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{
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int i;
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if (n==0) { mpfr_set_ui(x, 1, rnd); return; }
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mpfr_set(x, y, rnd);
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for (i=0;(1<<i)<=n;i++);
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/* now 2^(i-1) <= n < 2^i */
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for (i-=2; i>=0; i--) {
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mpfr_mul(x, x, x, rnd);
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if (n & (1<<i)) mpfr_mul(x, x, y, rnd);
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}
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return;
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}
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/* sets x to y^n */
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void mpfr_ui_pow_ui (mpfr_ptr x, unsigned int y, unsigned int n,
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unsigned char rnd)
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{
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int i;
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if (n==0) { mpfr_set_ui(x, 1, rnd); return; }
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mpfr_set_ui(x, y, rnd);
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for (i=0;(1<<i)<=n;i++);
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/* now 2^(i-1) <= n < 2^i */
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for (i-=2; i>=0; i--) {
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mpfr_mul(x, x, x, rnd);
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if (n & (1<<i)) mpfr_mul_ui(x, x, y, rnd);
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}
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return;
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}
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