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
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
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144

/*
    Copyright (C) 2017-2020 Daniel Schultz

    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 "longlong.h"
#include "nmod_mpoly.h"

FLINT_FORCE_INLINE
slong clog4(slong x)
{
    return (x <= 4) ? 0 : (slong) ((FLINT_BIT_COUNT(x - 1) - UWORD(1)) / UWORD(2));
}

void nmod_mpoly_geobucket_init(nmod_mpoly_geobucket_t B,
                                                    const nmod_mpoly_ctx_t ctx)
{
    slong i;
    for (i = 0; i < FLINT_BITS/2; i++)
    {
        nmod_mpoly_init(B->polys + i, ctx);
        nmod_mpoly_init(B->temps + i, ctx);
    }
    B->length = 0;
}

void nmod_mpoly_geobucket_clear(nmod_mpoly_geobucket_t B,
                                                    const nmod_mpoly_ctx_t ctx)
{
    slong i;
    for (i = 0; i < FLINT_BITS/2; i++)
    {
        nmod_mpoly_clear(B->polys + i, ctx);
        nmod_mpoly_clear(B->temps + i, ctx);
    }
}

/* empty out bucket B into polynomial p */
void nmod_mpoly_geobucket_empty(nmod_mpoly_t p, nmod_mpoly_geobucket_t B,
                                                    const nmod_mpoly_ctx_t ctx)
{
    slong i;

    if (B->length < 2)
    {
        if (B->length < 1)
            nmod_mpoly_zero(p, ctx);
        else
            nmod_mpoly_set(p, B->polys + 0, ctx);
    }
    else if (B->length == 2)
    {
        nmod_mpoly_add(p, B->polys + 1, B->polys + 0, ctx);
    }
    else
    {
        nmod_mpoly_add(B->temps + 1, B->polys + 1, B->polys + 0, ctx);
        for (i = 2; i < B->length - 1; i++)
            nmod_mpoly_add(B->temps + i, B->polys + i, B->temps + i - 1, ctx);
        nmod_mpoly_add(p, B->polys + i, B->temps + i - 1, ctx);
    }

    B->length = 0;
}

void nmod_mpoly_geobucket_fit_length(nmod_mpoly_geobucket_t B, slong len,
                                                    const nmod_mpoly_ctx_t ctx)
{
    slong j;
    for (j = B->length; j < len; j++)
        nmod_mpoly_zero(B->polys + j, ctx);
    B->length = j;
}

/* set bucket B to polynomial p */
void nmod_mpoly_geobucket_set(nmod_mpoly_geobucket_t B, nmod_mpoly_t p,
                                                    const nmod_mpoly_ctx_t ctx)
{
    slong i = clog4(p->length);
    B->length = 0;
    nmod_mpoly_geobucket_fit_length(B, i + 1, ctx);
    nmod_mpoly_swap(B->polys + i, p, ctx);
    B->length = i + 1;
}

/* internal function for fixing overflows */
static void _nmod_mpoly_geobucket_fix(nmod_mpoly_geobucket_t B, slong i,
                                                    const nmod_mpoly_ctx_t ctx)
{
    while (clog4((B->polys + i)->length) > i)
    {
        FLINT_ASSERT(i + 1 <= B->length);
        if (i + 1 == B->length)
        {
            B->length = i + 2;
            nmod_mpoly_set(B->polys + i + 1, B->polys + i, ctx);
        }
        else
        {
            nmod_mpoly_add(B->temps + i + 1, B->polys + i + 1, B->polys + i, ctx);
            nmod_mpoly_swap(B->polys + i + 1, B->temps + i + 1, ctx);
        }
        nmod_mpoly_zero(B->polys + i, ctx);
        i++;
    }
}

/* add polynomial p to bucket B */
void nmod_mpoly_geobucket_add(nmod_mpoly_geobucket_t B, nmod_mpoly_t p,
                                                    const nmod_mpoly_ctx_t ctx)
{
    slong i;

    if (nmod_mpoly_is_zero(p, ctx))
        return;

    i = clog4(p->length);
    nmod_mpoly_geobucket_fit_length(B, i + 1, ctx);
    nmod_mpoly_add(B->temps + i, B->polys + i, p, ctx);
    nmod_mpoly_swap(B->polys + i, B->temps + i, ctx);
    _nmod_mpoly_geobucket_fix(B, i, ctx);
}

/* sub polynomial p to buckect B */
void nmod_mpoly_geobucket_sub(nmod_mpoly_geobucket_t B, nmod_mpoly_t p,
                                                    const nmod_mpoly_ctx_t ctx)
{
    slong i;

    if (nmod_mpoly_is_zero(p, ctx))
        return;

    i = clog4(p->length);
    nmod_mpoly_geobucket_fit_length(B, i + 1, ctx);
    nmod_mpoly_sub(B->temps + i, B->polys + i, p, ctx);
    nmod_mpoly_swap(B->polys + i, B->temps + i, ctx);
    _nmod_mpoly_geobucket_fix(B, i, ctx);
}