46 lines
1.4 KiB
C
46 lines
1.4 KiB
C
/* mpz_get_si(integer) -- Return the least significant digit from INTEGER.
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Copyright 1991, 1993, 1994, 1995, 2000, 2001, 2002, 2006 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 "mpir.h"
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#include "gmp-impl.h"
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mpir_si
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mpz_get_si (mpz_srcptr z)
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{
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mp_ptr zp = z->_mp_d;
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mp_size_t size = z->_mp_size;
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mp_limb_t zl = zp[0];
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#if GMP_NAIL_BITS != 0
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if (GMP_UI_MAX > GMP_NUMB_MAX && ABS (size) >= 2)
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zl |= zp[1] << GMP_NUMB_BITS;
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#endif
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if (size > 0)
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return (mpir_si) zl & GMP_SI_MAX;
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else if (size < 0)
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/* This expression is necessary to properly handle 0x80000000 */
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return ~(((mpir_si) zl - 1L) & GMP_SI_MAX);
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else
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return 0;
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}
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