1 /*
2 Copyright (C) 2017 Daniel Schultz
3
4 This file is part of FLINT.
5
6 FLINT is free software: you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version. See <https://www.gnu.org/licenses/>.
10 */
11
12 #include "mpoly.h"
13
14 /* !!! this file DOES need to change with new orderings */
15
16 /*
17 compute number of bits required to store user_exp in packed format
18 the returned number of bits includes space for a zero'd signed bit
19 */
mpoly_exp_bits_required_ui(const ulong * user_exp,const mpoly_ctx_t mctx)20 flint_bitcnt_t mpoly_exp_bits_required_ui(const ulong * user_exp,
21 const mpoly_ctx_t mctx)
22 {
23 slong i, nfields = mctx->nfields;
24 ulong max;
25
26 max = user_exp[0];
27 if (mctx->deg)
28 {
29 for (i = 1; i < nfields - 1; i++)
30 {
31 max += user_exp[i];
32 if (max < user_exp[i])
33 return 2*FLINT_BITS;
34 }
35 }
36 else
37 {
38 for (i = 1; i < nfields; i++)
39 {
40 max |= user_exp[i];
41 }
42 }
43
44 return 1 + FLINT_BIT_COUNT(max);
45 }
46
47 /*
48 compute number of bits required to store user_exp in packed format
49 the returned number of bits includes space for a zero'd signed bit
50 */
mpoly_exp_bits_required_ffmpz(const fmpz * user_exp,const mpoly_ctx_t mctx)51 flint_bitcnt_t mpoly_exp_bits_required_ffmpz(const fmpz * user_exp,
52 const mpoly_ctx_t mctx)
53 {
54 slong i, nvars = mctx->nvars;
55 flint_bitcnt_t exp_bits;
56
57 if (mctx->deg)
58 {
59 fmpz_t deg;
60 fmpz_init_set(deg, user_exp + 0);
61 for (i = 1; i < nvars; i++)
62 {
63 fmpz_add(deg, deg, user_exp + i);
64 }
65 exp_bits = 1 + fmpz_bits(deg);
66 fmpz_clear(deg);
67 }
68 else
69 {
70 exp_bits = fmpz_bits(user_exp + 0);
71 for (i = 1; i < nvars; i++)
72 {
73 exp_bits = FLINT_MAX(exp_bits, fmpz_bits(user_exp + i));
74 }
75 exp_bits += 1;
76 }
77
78 return exp_bits;
79 }
80
81 /*
82 compute number of bits required to store user_exp in packed format
83 the returned number of bits includes space for a zero'd signed bit
84 */
mpoly_exp_bits_required_pfmpz(fmpz * const * user_exp,const mpoly_ctx_t mctx)85 flint_bitcnt_t mpoly_exp_bits_required_pfmpz(fmpz * const * user_exp,
86 const mpoly_ctx_t mctx)
87 {
88 slong i, nvars = mctx->nvars;
89 flint_bitcnt_t exp_bits;
90
91 if (mctx->deg)
92 {
93 fmpz_t deg;
94 fmpz_init_set(deg, user_exp[0]);
95 for (i = 1; i < nvars; i++)
96 {
97 fmpz_add(deg, deg, user_exp[i]);
98 }
99 exp_bits = 1 + fmpz_bits(deg);
100 fmpz_clear(deg);
101 }
102 else
103 {
104 exp_bits = fmpz_bits(user_exp[0]);
105 for (i = 1; i < nvars; i++)
106 {
107 exp_bits = FLINT_MAX(exp_bits, fmpz_bits(user_exp[i]));
108 }
109 exp_bits += 1;
110 }
111
112 return exp_bits;
113 }
114