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
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
/*
Copyright (C) 2014 Fredrik Johansson
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 "mag.h"
void
mag_addmul(mag_t z, const mag_t x, const mag_t y)
{
if (mag_is_zero(z))
{
mag_mul(z, x, y);
}
else if (mag_is_inf(z) || mag_is_inf(x) || mag_is_inf(y))
{
mag_inf(z);
}
else if (mag_is_zero(x) || mag_is_zero(y))
{
return;
}
else
{
slong shift;
fmpz_t e;
fmpz_init(e);
/* x*y < 2^e */
_fmpz_add2_fast(e, MAG_EXPREF(x), MAG_EXPREF(y), 0);
shift = _fmpz_sub_small(MAG_EXPREF(z), e);
if (shift >= 0)
{
if (shift >= MAG_BITS)
MAG_MAN(z)++;
else
MAG_MAN(z) = MAG_MAN(z) + (MAG_FIXMUL(MAG_MAN(x),
MAG_MAN(y)) >> shift) + LIMB_ONE;
}
else
{
shift = -shift;
fmpz_swap(MAG_EXPREF(z), e);
if (shift >= MAG_BITS)
MAG_MAN(z) = MAG_FIXMUL(MAG_MAN(x), MAG_MAN(y))
+ (2 * LIMB_ONE);
else
MAG_MAN(z) = MAG_FIXMUL(MAG_MAN(x), MAG_MAN(y))
+ (MAG_MAN(z) >> shift) + (2 * LIMB_ONE);
MAG_ADJUST_ONE_TOO_SMALL(z);
}
MAG_ADJUST_ONE_TOO_LARGE(z);
fmpz_clear(e);
}
}