67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/* mpf_trunc -- truncate an mpf to an integer.
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Copyright 2001 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 "gmp.h"
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#include "gmp-impl.h"
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/* Notice the use of prec+1 ensures mpf_trunc is equivalent to mpf_set if u
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is already an integer. */
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void
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mpf_trunc (mpf_ptr r, mpf_srcptr u)
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{
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mp_ptr rp;
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mp_srcptr up;
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mp_size_t size, asize, prec;
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mp_exp_t exp;
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exp = EXP(u);
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size = SIZ(u);
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if (size == 0 || exp <= 0)
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{
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/* u is only a fraction */
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SIZ(r) = 0;
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EXP(r) = 0;
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return;
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}
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up = PTR(u);
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EXP(r) = exp;
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asize = ABS (size);
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up += asize;
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/* skip fraction part of u */
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asize = MIN (asize, exp);
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/* don't lose precision in the copy */
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prec = PREC(r) + 1;
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/* skip excess over target precision */
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asize = MIN (asize, prec);
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up -= asize;
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rp = PTR(r);
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SIZ(r) = (size >= 0 ? asize : -asize);
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if (rp != up)
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MPN_COPY_INCR (rp, up, asize);
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}
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