| 1 | /* mpz_divexact_ui -- exact division mpz by ulong. |
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| 2 | |
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| 3 | Copyright 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 | |
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| 23 | #include "gmp.h" |
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| 24 | #include "gmp-impl.h" |
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| 25 | |
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| 26 | void |
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| 27 | mpz_divexact_ui (mpz_ptr dst, mpz_srcptr src, unsigned long divisor) |
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| 28 | { |
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| 29 | mp_size_t size, abs_size; |
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| 30 | mp_ptr dst_ptr; |
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| 31 | |
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| 32 | if (divisor == 0) |
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| 33 | DIVIDE_BY_ZERO; |
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| 34 | |
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| 35 | /* For nails don't try to be clever if d is bigger than a limb, just fake |
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| 36 | up an mpz_t and go to the main mpz_divexact. */ |
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| 37 | if (divisor > GMP_NUMB_MAX) |
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| 38 | { |
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| 39 | mp_limb_t dlimbs[2]; |
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| 40 | mpz_t dz; |
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| 41 | ALLOC(dz) = 2; |
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| 42 | PTR(dz) = dlimbs; |
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| 43 | mpz_set_ui (dz, divisor); |
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| 44 | mpz_divexact (dst, src, dz); |
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| 45 | return; |
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| 46 | } |
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| 47 | |
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| 48 | size = SIZ(src); |
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| 49 | if (size == 0) |
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| 50 | { |
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| 51 | SIZ(dst) = 0; |
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| 52 | return; |
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| 53 | } |
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| 54 | abs_size = ABS (size); |
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| 55 | |
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| 56 | MPZ_REALLOC (dst, abs_size); |
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| 57 | dst_ptr = PTR(dst); |
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| 58 | |
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| 59 | MPN_DIVREM_OR_DIVEXACT_1 (dst_ptr, PTR(src), abs_size, (mp_limb_t) divisor); |
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| 60 | abs_size -= (dst_ptr[abs_size-1] == 0); |
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| 61 | SIZ(dst) = (size >= 0 ? abs_size : -abs_size); |
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| 62 | } |
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