| 1 | /* mpz_set_d(integer, val) -- Assign INTEGER with a double value VAL. |
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| 2 | |
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| 3 | Copyright 1995, 1996, 2000, 2001, 2002 Free Software Foundation, Inc. |
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| 4 | |
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| 5 | This file is part of the GNU MP Library. |
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| 6 | |
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| 7 | The GNU MP Library is free software; you can redistribute it and/or modify |
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| 8 | it under the terms of the GNU Lesser General Public License as published by |
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| 9 | the Free Software Foundation; either version 2.1 of the License, or (at your |
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| 10 | option) any later version. |
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| 11 | |
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| 12 | The GNU MP Library is distributed in the hope that it will be useful, but |
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| 13 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
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| 14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
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| 15 | License for more details. |
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| 16 | |
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| 17 | You should have received a copy of the GNU Lesser General Public License |
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| 18 | along with the GNU MP Library; see the file COPYING.LIB. If not, write to |
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| 19 | the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
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| 20 | MA 02111-1307, USA. */ |
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| 21 | |
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| 22 | #include "gmp.h" |
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| 23 | #include "gmp-impl.h" |
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| 24 | |
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| 25 | void |
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| 26 | mpz_set_d (mpz_ptr r, double d) |
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| 27 | { |
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| 28 | int negative; |
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| 29 | mp_limb_t tp[LIMBS_PER_DOUBLE]; |
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| 30 | mp_ptr rp; |
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| 31 | mp_size_t rn; |
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| 32 | |
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| 33 | negative = d < 0; |
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| 34 | d = ABS (d); |
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| 35 | |
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| 36 | /* Handle small arguments quickly. */ |
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| 37 | if (d < MP_BASE_AS_DOUBLE) |
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| 38 | { |
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| 39 | mp_limb_t tmp; |
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| 40 | tmp = d; |
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| 41 | PTR(r)[0] = tmp; |
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| 42 | SIZ(r) = negative ? -(tmp != 0) : (tmp != 0); |
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| 43 | return; |
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| 44 | } |
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| 45 | |
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| 46 | rn = __gmp_extract_double (tp, d); |
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| 47 | |
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| 48 | if (ALLOC(r) < rn) |
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| 49 | _mpz_realloc (r, rn); |
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| 50 | |
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| 51 | rp = PTR (r); |
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| 52 | |
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| 53 | #if BITS_PER_MP_LIMB == 32 |
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| 54 | switch (rn) |
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| 55 | { |
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| 56 | default: |
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| 57 | MPN_ZERO (rp, rn - 3); |
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| 58 | rp += rn - 3; |
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| 59 | /* fall through */ |
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| 60 | case 3: |
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| 61 | rp[2] = tp[2]; |
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| 62 | rp[1] = tp[1]; |
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| 63 | rp[0] = tp[0]; |
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| 64 | break; |
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| 65 | case 2: |
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| 66 | rp[1] = tp[2]; |
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| 67 | rp[0] = tp[1]; |
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| 68 | break; |
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| 69 | case 1: |
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| 70 | /* handled in "small aguments" case above */ |
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| 71 | abort (); |
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| 72 | } |
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| 73 | #else |
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| 74 | switch (rn) |
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| 75 | { |
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| 76 | default: |
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| 77 | MPN_ZERO (rp, rn - 2); |
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| 78 | rp += rn - 2; |
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| 79 | /* fall through */ |
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| 80 | case 2: |
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| 81 | rp[1] = tp[1], rp[0] = tp[0]; |
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| 82 | break; |
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| 83 | case 1: |
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| 84 | /* handled in "small aguments" case above */ |
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| 85 | abort (); |
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| 86 | } |
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| 87 | #endif |
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| 88 | |
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| 89 | SIZ(r) = negative ? -rn : rn; |
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| 90 | } |
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