60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
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/* mpz_mod -- The mathematical mod function.
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Copyright 1991, 1993, 1994, 1995, 1996, 2001, 2002, 2005 Free Software
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Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP 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 GNU MP 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 MP Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include "gmp.h"
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#include "gmp-impl.h"
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void
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mpz_mod (mpz_ptr rem, mpz_srcptr dividend, mpz_srcptr divisor)
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{
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mp_size_t divisor_size = divisor->_mp_size;
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mpz_t temp_divisor; /* N.B.: lives until function returns! */
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TMP_DECL;
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TMP_MARK;
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/* We need the original value of the divisor after the remainder has been
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preliminary calculated. We have to copy it to temporary space if it's
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the same variable as REM. */
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if (rem == divisor)
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{
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MPZ_TMP_INIT (temp_divisor, ABS (divisor_size));
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mpz_set (temp_divisor, divisor);
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divisor = temp_divisor;
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}
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mpz_tdiv_r (rem, dividend, divisor);
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if (rem->_mp_size != 0)
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{
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if (dividend->_mp_size < 0)
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{
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if (divisor->_mp_size < 0)
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mpz_sub (rem, rem, divisor);
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else
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mpz_add (rem, rem, divisor);
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}
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}
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TMP_FREE;
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}
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