106 lines
2.8 KiB
C
106 lines
2.8 KiB
C
/* mpz_set_d(integer, val) -- Assign INTEGER with a double value VAL.
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Copyright 1995, 1996, 2000, 2001, 2002, 2003 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 "config.h"
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#if HAVE_FLOAT_H
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#include <float.h> /* for DBL_MAX */
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#endif
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#include "gmp.h"
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#include "gmp-impl.h"
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/* We used to have a special case for d < MP_BASE_AS_DOUBLE, just casting
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double -> limb. Unfortunately gcc 3.3 on powerpc970-apple-darwin6.8.5
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got this wrong. (It assumed __fixunsdfdi returned its result in a single
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64-bit register, where instead that function followed the calling
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conventions and gave the result in two parts r3 and r4.) Hence the use
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of __gmp_extract_double in all cases. */
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void
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mpz_set_d (mpz_ptr r, double d)
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{
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int negative;
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mp_limb_t tp[LIMBS_PER_DOUBLE];
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mp_ptr rp;
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mp_size_t rn;
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DOUBLE_NAN_INF_ACTION (d,
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__gmp_invalid_operation (),
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__gmp_invalid_operation ());
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negative = d < 0;
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d = ABS (d);
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rn = __gmp_extract_double (tp, d);
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if (ALLOC(r) < rn)
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_mpz_realloc (r, rn);
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rp = PTR (r);
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switch (rn)
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{
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default:
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MPN_ZERO (rp, rn - LIMBS_PER_DOUBLE);
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rp += rn - LIMBS_PER_DOUBLE;
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/* fall through */
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#if LIMBS_PER_DOUBLE == 2
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case 2:
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rp[1] = tp[1], rp[0] = tp[0];
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break;
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case 1:
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rp[0] = tp[1];
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break;
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#endif
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#if LIMBS_PER_DOUBLE == 3
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case 3:
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rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0];
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break;
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case 2:
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rp[1] = tp[2], rp[0] = tp[1];
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break;
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case 1:
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rp[0] = tp[2];
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break;
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#endif
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#if LIMBS_PER_DOUBLE == 4
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case 4:
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rp[3] = tp[3], rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0];
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break;
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case 3:
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rp[2] = tp[3], rp[1] = tp[2], rp[0] = tp[1];
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break;
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case 2:
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rp[1] = tp[3], rp[0] = tp[2];
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break;
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case 1:
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rp[0] = tp[3];
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break;
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#endif
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case 0:
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break;
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}
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SIZ(r) = negative ? -rn : rn;
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}
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