aboutsummaryrefslogtreecommitdiff
path: root/source/random.c
blob: 04b746d55bd4be9d00000ed04c8264c9ed7f9260 (plain)
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

/*============================================================================

This C source file is part of TestFloat, Release 3d, a package of programs for
testing the correctness of floating-point arithmetic complying with the IEEE
Standard for Floating-Point, by John R. Hauser.

Copyright 2011, 2012, 2013, 2014 The Regents of the University of California.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

 1. Redistributions of source code must retain the above copyright notice,
    this list of conditions, and the following disclaimer.

 2. Redistributions in binary form must reproduce the above copyright notice,
    this list of conditions, and the following disclaimer in the documentation
    and/or other materials provided with the distribution.

 3. Neither the name of the University nor the names of its contributors may
    be used to endorse or promote products derived from this software without
    specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=============================================================================*/

#include <stdint.h>
#include <stdlib.h>
#include "platform.h"
#include "random.h"

uint_fast8_t random_ui8( void )
{

    return rand()>>4 & 0xFF;

}

uint_fast16_t random_ui16( void )
{

    return (rand() & 0x0FF0)<<4 | (rand()>>4 & 0xFF);

}

uint_fast32_t random_ui32( void )
{

    return
          (uint_fast32_t) (rand() & 0x0FF0)<<20
        | (uint_fast32_t) (rand() & 0x0FF0)<<12
        | (rand() & 0x0FF0)<<4
        | (rand()>>4 & 0xFF);

}

uint_fast64_t random_ui64( void )
{

    return (uint_fast64_t) random_ui32()<<32 | random_ui32();

}

uint_fast8_t randomN_ui8( uint_fast8_t N )
{
    uint_fast8_t scale, z;

    scale = 0;
    while ( N < 0x80 ) {
        ++scale;
        N <<= 1;
    }
    do {
        z = random_ui8();
    } while ( N <= z );
    return z>>scale;

}

uint_fast16_t randomN_ui16( uint_fast16_t N )
{
    uint_fast16_t scale, z;

    scale = 0;
    while ( N < 0x8000 ) {
        ++scale;
        N <<= 1;
    }
    do {
        z = random_ui16();
    } while ( N <= z );
    return z>>scale;

}

uint_fast32_t randomN_ui32( uint_fast32_t N )
{
    uint_fast32_t scale, z;

    scale = 0;
    while ( N < 0x8000 ) {
        ++scale;
        N <<= 1;
    }
    do {
        z = random_ui32();
    } while ( N <= z );
    return z>>scale;

}

uint_fast64_t randomN_ui64( uint_fast64_t N )
{
    uint_fast64_t scale, z;

    scale = 0;
    while ( N < 0x8000 ) {
        ++scale;
        N <<= 1;
    }
    do {
        z = random_ui64();
    } while ( N <= z );
    return z>>scale;

}