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
|
/* Apache License, Version 2.0 */
#include "testing/testing.h"
#include "BLI_math.h"
/* In tests below, when we are using -1.0f as max_diff value, we actually turn the function into a
* pure-ULP one. */
/* Put this here, since we cannot use BLI_assert() in inline math files it seems... */
TEST(math_base, CompareFFRelativeValid)
{
EXPECT_TRUE(sizeof(float) == sizeof(int));
}
TEST(math_base, CompareFFRelativeNormal)
{
float f1 = 1.99999988f; /* *(float *)&(*(int *)&f2 - 1) */
float f2 = 2.00000000f;
float f3 = 2.00000048f; /* *(float *)&(*(int *)&f2 + 2) */
float f4 = 2.10000000f; /* *(float *)&(*(int *)&f2 + 419430) */
const float max_diff = FLT_EPSILON * 0.1f;
EXPECT_TRUE(compare_ff_relative(f1, f2, max_diff, 1));
EXPECT_TRUE(compare_ff_relative(f2, f1, max_diff, 1));
EXPECT_TRUE(compare_ff_relative(f3, f2, max_diff, 2));
EXPECT_TRUE(compare_ff_relative(f2, f3, max_diff, 2));
EXPECT_FALSE(compare_ff_relative(f3, f2, max_diff, 1));
EXPECT_FALSE(compare_ff_relative(f2, f3, max_diff, 1));
EXPECT_FALSE(compare_ff_relative(f3, f2, -1.0f, 1));
EXPECT_FALSE(compare_ff_relative(f2, f3, -1.0f, 1));
EXPECT_TRUE(compare_ff_relative(f3, f2, -1.0f, 2));
EXPECT_TRUE(compare_ff_relative(f2, f3, -1.0f, 2));
EXPECT_FALSE(compare_ff_relative(f4, f2, max_diff, 64));
EXPECT_FALSE(compare_ff_relative(f2, f4, max_diff, 64));
EXPECT_TRUE(compare_ff_relative(f1, f3, max_diff, 64));
EXPECT_TRUE(compare_ff_relative(f3, f1, max_diff, 64));
}
TEST(math_base, CompareFFRelativeZero)
{
float f0 = 0.0f;
float f1 = 4.2038954e-045f; /* *(float *)&(*(int *)&f0 + 3) */
float fn0 = -0.0f;
float fn1 = -2.8025969e-045f; /* *(float *)&(*(int *)&fn0 - 2) */
const float max_diff = FLT_EPSILON * 0.1f;
EXPECT_TRUE(compare_ff_relative(f0, f1, -1.0f, 3));
EXPECT_TRUE(compare_ff_relative(f1, f0, -1.0f, 3));
EXPECT_FALSE(compare_ff_relative(f0, f1, -1.0f, 1));
EXPECT_FALSE(compare_ff_relative(f1, f0, -1.0f, 1));
EXPECT_TRUE(compare_ff_relative(fn0, fn1, -1.0f, 8));
EXPECT_TRUE(compare_ff_relative(fn1, fn0, -1.0f, 8));
EXPECT_TRUE(compare_ff_relative(f0, f1, max_diff, 1));
EXPECT_TRUE(compare_ff_relative(f1, f0, max_diff, 1));
EXPECT_TRUE(compare_ff_relative(fn0, f0, max_diff, 1));
EXPECT_TRUE(compare_ff_relative(f0, fn0, max_diff, 1));
EXPECT_TRUE(compare_ff_relative(f0, fn1, max_diff, 1));
EXPECT_TRUE(compare_ff_relative(fn1, f0, max_diff, 1));
/* Note: in theory, this should return false, since 0.0f and -0.0f have 0x80000000 diff,
* but overflow in subtraction seems to break something here
* (abs(*(int *)&fn0 - *(int *)&f0) == 0x80000000 == fn0), probably because int32 cannot
* hold this abs value. this is yet another illustration of why one shall never use (near-)zero
* floats in pure-ULP comparison. */
// EXPECT_FALSE(compare_ff_relative(fn0, f0, -1.0f, 1024));
// EXPECT_FALSE(compare_ff_relative(f0, fn0, -1.0f, 1024));
EXPECT_FALSE(compare_ff_relative(fn0, f1, -1.0f, 1024));
EXPECT_FALSE(compare_ff_relative(f1, fn0, -1.0f, 1024));
}
TEST(math_base, Log2FloorU)
{
EXPECT_EQ(log2_floor_u(0), 0);
EXPECT_EQ(log2_floor_u(1), 0);
EXPECT_EQ(log2_floor_u(2), 1);
EXPECT_EQ(log2_floor_u(3), 1);
EXPECT_EQ(log2_floor_u(4), 2);
EXPECT_EQ(log2_floor_u(5), 2);
EXPECT_EQ(log2_floor_u(6), 2);
EXPECT_EQ(log2_floor_u(7), 2);
EXPECT_EQ(log2_floor_u(8), 3);
EXPECT_EQ(log2_floor_u(9), 3);
EXPECT_EQ(log2_floor_u(123456), 16);
}
TEST(math_base, Log2CeilU)
{
EXPECT_EQ(log2_ceil_u(0), 0);
EXPECT_EQ(log2_ceil_u(1), 0);
EXPECT_EQ(log2_ceil_u(2), 1);
EXPECT_EQ(log2_ceil_u(3), 2);
EXPECT_EQ(log2_ceil_u(4), 2);
EXPECT_EQ(log2_ceil_u(5), 3);
EXPECT_EQ(log2_ceil_u(6), 3);
EXPECT_EQ(log2_ceil_u(7), 3);
EXPECT_EQ(log2_ceil_u(8), 3);
EXPECT_EQ(log2_ceil_u(9), 4);
EXPECT_EQ(log2_ceil_u(123456), 17);
}
|
