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
145
|
#ifndef __FP_MATH_H__
#define __FP_MATH_H__
#ifndef __KERNEL__
#include <stdint.h>
#define abs(x) (((x) < 0) ? -(x) : x)
#endif
// Use 64-bit because we want to track things at the nanosecond scale.
// This can lead to very large numbers.
typedef int64_t fpbuf_t;
typedef struct
{
fpbuf_t val;
} fp_t;
#define FP_SHIFT 10
#define ROUND_BIT (FP_SHIFT - 1)
#define _fp(x) ((fp_t) {x})
#ifdef __KERNEL__
static const fp_t LITMUS_FP_ZERO = {.val = 0};
static const fp_t LITMUS_FP_ONE = {.val = (1 << FP_SHIFT)};
#endif
static inline fp_t FP(fpbuf_t x)
{
return _fp(((fpbuf_t) x) << FP_SHIFT);
}
/* divide two integers to obtain a fixed point value */
static inline fp_t _frac(fpbuf_t a, fpbuf_t b)
{
return _fp(FP(a).val / (b));
}
static inline fpbuf_t _point(fp_t x)
{
return (x.val % (1 << FP_SHIFT));
}
#define fp2str(x) x.val
/*(x.val >> FP_SHIFT), (x.val % (1 << FP_SHIFT)) */
#define _FP_ "%ld/1024"
static inline fpbuf_t _floor(fp_t x)
{
return x.val >> FP_SHIFT;
}
/* FIXME: negative rounding */
static inline fpbuf_t _round(fp_t x)
{
return _floor(x) + ((x.val >> ROUND_BIT) & 1);
}
/* multiply two fixed point values */
static inline fp_t _mul(fp_t a, fp_t b)
{
return _fp((a.val * b.val) >> FP_SHIFT);
}
static inline fp_t _div(fp_t a, fp_t b)
{
#if !defined(__KERNEL__) && !defined(unlikely)
#define unlikely(x) (x)
#define DO_UNDEF_UNLIKELY
#endif
/* try not to overflow */
if (unlikely( a.val > (2l << ((sizeof(fpbuf_t)*8) - FP_SHIFT)) ))
return _fp((a.val / b.val) << FP_SHIFT);
else
return _fp((a.val << FP_SHIFT) / b.val);
#ifdef DO_UNDEF_UNLIKELY
#undef unlikely
#undef DO_UNDEF_UNLIKELY
#endif
}
static inline fp_t _add(fp_t a, fp_t b)
{
return _fp(a.val + b.val);
}
static inline fp_t _sub(fp_t a, fp_t b)
{
return _fp(a.val - b.val);
}
static inline fp_t _neg(fp_t x)
{
return _fp(-x.val);
}
static inline fp_t _abs(fp_t x)
{
return _fp(abs(x.val));
}
/* works the same as casting float/double to integer */
static inline fpbuf_t _fp_to_integer(fp_t x)
{
return _floor(_abs(x)) * ((x.val > 0) ? 1 : -1);
}
static inline fp_t _integer_to_fp(fpbuf_t x)
{
return _frac(x,1);
}
static inline int _leq(fp_t a, fp_t b)
{
return a.val <= b.val;
}
static inline int _geq(fp_t a, fp_t b)
{
return a.val >= b.val;
}
static inline int _lt(fp_t a, fp_t b)
{
return a.val < b.val;
}
static inline int _gt(fp_t a, fp_t b)
{
return a.val > b.val;
}
static inline int _eq(fp_t a, fp_t b)
{
return a.val == b.val;
}
static inline fp_t _max(fp_t a, fp_t b)
{
if (a.val < b.val)
return b;
else
return a;
}
#endif
|
