71 lines
1.8 KiB
C
71 lines
1.8 KiB
C
/* mpz_lcm_ui -- least common multiple of mpz and ulong.
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Copyright 2001, 2002, 2004 Free Software 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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#include "longlong.h"
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void
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mpz_lcm_ui (mpz_ptr r, mpz_srcptr u, mpir_ui v)
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{
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mp_size_t usize;
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mp_srcptr up;
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mp_ptr rp;
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mpir_ui g;
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mp_limb_t c;
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#if BITS_PER_UI > GMP_NUMB_BITS /* avoid warnings about shift amount */
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if (v > GMP_NUMB_MAX)
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{
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mpz_t vz;
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mp_limb_t vlimbs[2];
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vlimbs[0] = v & GMP_NUMB_MASK;
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vlimbs[1] = v >> GMP_NUMB_BITS;
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PTR(vz) = vlimbs;
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SIZ(vz) = 2;
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mpz_lcm (r, u, vz);
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return;
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}
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#endif
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/* result zero if either operand zero */
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usize = SIZ(u);
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if (usize == 0 || v == 0)
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{
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SIZ(r) = 0;
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return;
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}
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usize = ABS(usize);
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MPZ_REALLOC (r, usize+1);
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up = PTR(u);
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g = (mpir_ui) mpn_gcd_1 (up, usize, (mp_limb_t) v);
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v /= g;
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rp = PTR(r);
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c = mpn_mul_1 (rp, up, usize, (mp_limb_t) v);
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rp[usize] = c;
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usize += (c != 0);
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SIZ(r) = usize;
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}
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