flint-sys 0.9.0

Bindings to the FLINT C library
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

/*
    Copyright (C) 2009, 2011 William Hart

    This file is part of FLINT.

    FLINT is free software: you can redistribute it and/or modify it under
    the terms of the GNU Lesser General Public License (LGPL) as published
    by the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.  See <https://www.gnu.org/licenses/>.
*/

#include "mpn_extras.h"
#include "fft.h"

/* WARNING: relies on GCC's handling of >> as arithmetic shift right */

void mpn_div_2expmod_2expp1(mp_limb_t * t, mp_limb_t * i1, mp_size_t limbs, flint_bitcnt_t d)
{
   mp_limb_t lo;
   mp_limb_t * ptr;
   mp_limb_signed_t hi;

   if (d == 0)
   {
      if (t != i1)
         flint_mpn_copyi(t, i1, limbs + 1);
   } else
   {
      hi = i1[limbs];
      lo = mpn_rshift(t, i1, limbs + 1, d);
      t[limbs] = (hi >> d);
      ptr = t + limbs - 1;
      sub_ddmmss(ptr[1], ptr[0], ptr[1], ptr[0], (mp_limb_t) 0, lo);
   }
}