1 /* emacs edit mode for this file is -*- C++ -*- */
2
3
4 #include "config.h"
5
6
7 #include <time.h>
8
9 #include "cf_assert.h"
10
11 #include "cf_defs.h"
12 #include "cf_random.h"
13 #include "ffops.h"
14 #include "gfops.h"
15 #include "imm.h"
16
17 #ifdef HAVE_FLINT
18 extern "C"
19 {
20 #ifndef __GMP_BITS_PER_MP_LIMB
21 #define __GMP_BITS_PER_MP_LIMB GMP_LIMB_BITS
22 #endif
23 #include <flint/flint.h>
24
25 GLOBAL_VAR flint_rand_t FLINTrandom;
26 }
27 #endif
28
29 class RandomGenerator {
30 private:
31 const int ia, im, iq, ir, deflt;
32 int s;
33
34 // s must not equal zero!
seedInit(int ss)35 void seedInit( int ss ) { s = ((ss == 0) ? deflt : ss); }
36 public:
37 RandomGenerator();
38 RandomGenerator( int ss );
~RandomGenerator()39 ~RandomGenerator() {}
40 int generate();
seed(int ss)41 void seed( int ss ) { seedInit( ss ); }
42 };
43
RandomGenerator()44 RandomGenerator::RandomGenerator() : ia(16807), im(2147483647), iq(127773), ir(2836), deflt(123459876)
45 {
46 seedInit( (int)time( 0 ) );
47 }
48
RandomGenerator(int ss)49 RandomGenerator::RandomGenerator( int ss ) : ia(16807), im(2147483647), iq(127773), ir(2836), deflt(123459876)
50 {
51 seedInit( ss );
52 }
53
54 int
generate()55 RandomGenerator::generate()
56 {
57 int k;
58
59 k = s/iq;
60 s = ia*(s-k*iq)-ir*k;
61 if ( s < 0 ) s += im;
62
63 return s;
64 }
65
66 INST_VAR RandomGenerator ranGen;
67
generate() const68 CanonicalForm FFRandom::generate () const
69 {
70 return CanonicalForm( int2imm_p( factoryrandom( ff_prime ) ) );
71 }
72
clone() const73 CFRandom * FFRandom::clone () const
74 {
75 return new FFRandom();
76 }
77
generate() const78 CanonicalForm GFRandom::generate () const
79 {
80 int i= factoryrandom( gf_q );
81 if ( i == gf_q1 ) i++;
82 return CanonicalForm( int2imm_gf( i ) );
83 }
84
clone() const85 CFRandom * GFRandom::clone () const
86 {
87 return new GFRandom();
88 }
89
90
IntRandom()91 IntRandom::IntRandom()
92 {
93 max = 50;
94 }
95
IntRandom(int m)96 IntRandom::IntRandom( int m )
97 {
98 max = m;
99 }
100
~IntRandom()101 IntRandom::~IntRandom() {}
102
generate() const103 CanonicalForm IntRandom::generate() const
104 {
105 return factoryrandom( 2*max )-max;
106 }
107
clone() const108 CFRandom * IntRandom::clone() const
109 {
110 return new IntRandom( max );
111 }
112
AlgExtRandomF()113 AlgExtRandomF::AlgExtRandomF()
114 {
115 ASSERT( 0, "not a valid random generator" );
116 }
117
AlgExtRandomF(const AlgExtRandomF &)118 AlgExtRandomF::AlgExtRandomF( const AlgExtRandomF & )
119 {
120 ASSERT( 0, "not a valid random generator" );
121 }
122
operator =(const AlgExtRandomF &)123 AlgExtRandomF& AlgExtRandomF::operator= ( const AlgExtRandomF & )
124 {
125 ASSERT( 0, "not a valid random generator" );
126 return *this;
127 }
128
AlgExtRandomF(const Variable & v)129 AlgExtRandomF::AlgExtRandomF( const Variable & v )
130 {
131 ASSERT( v.level() < 0, "not an algebraic extension" );
132 algext = v;
133 n = degree( getMipo( v ) );
134 gen = CFRandomFactory::generate();
135 }
136
AlgExtRandomF(const Variable & v1,const Variable & v2)137 AlgExtRandomF::AlgExtRandomF( const Variable & v1, const Variable & v2 )
138 {
139 ASSERT( v1.level() < 0 && v2.level() < 0 && v1 != v2, "not an algebraic extension" );
140 algext = v2;
141 n = degree( getMipo( v2 ) );
142 gen = new AlgExtRandomF( v1 );
143 }
144
AlgExtRandomF(const Variable & v,CFRandom * g,int nn)145 AlgExtRandomF::AlgExtRandomF( const Variable & v, CFRandom * g, int nn )
146 {
147 algext = v;
148 n = nn;
149 gen = g;
150 }
151
~AlgExtRandomF()152 AlgExtRandomF::~AlgExtRandomF()
153 {
154 delete gen;
155 }
156
generate() const157 CanonicalForm AlgExtRandomF::generate() const
158 {
159 CanonicalForm result;
160 for ( int i = 0; i < n; i++ )
161 result += power( algext, i ) * gen->generate();
162 return result;
163 }
164
clone() const165 CFRandom * AlgExtRandomF::clone () const
166 {
167 return new AlgExtRandomF( algext, gen->clone(), n );
168 }
169
generate()170 CFRandom * CFRandomFactory::generate()
171 {
172 if ( getCharacteristic() == 0 )
173 return new IntRandom();
174 if ( getGFDegree() > 1 )
175 return new GFRandom();
176 else
177 return new FFRandom();
178 }
179
factoryrandom(int n)180 int factoryrandom( int n )
181 {
182 if ( n == 0 )
183 return (int)ranGen.generate();
184 else
185 return ranGen.generate() % n;
186 }
187
188
factoryseed(int s)189 void factoryseed ( int s )
190 {
191 ranGen.seed( s );
192
193 #ifdef HAVE_FLINT
194 flint_randinit(FLINTrandom);
195 #endif
196 }
197