Convert a loop to range-based for.
[movit] / fp16_test.cpp
1 #include "fp16.h"
2
3 #include <cmath>
4 #include <gtest/gtest.h>
5
6 namespace movit {
7 namespace {
8
9 fp16_int_t make_fp16(unsigned short x)
10 {
11         fp16_int_t ret;
12         ret.val = x;
13         return ret;
14 }
15
16 }  // namespace
17
18 TEST(FP16Test, Simple) {
19         EXPECT_EQ(0x0000, fp32_to_fp16(0.0).val);
20         EXPECT_DOUBLE_EQ(0.0, fp16_to_fp32(make_fp16(0x0000)));
21
22         EXPECT_EQ(0x3c00, fp32_to_fp16(1.0).val);
23         EXPECT_DOUBLE_EQ(1.0, fp16_to_fp32(make_fp16(0x3c00)));
24
25         EXPECT_EQ(0x3555, fp32_to_fp16(1.0 / 3.0).val);
26         EXPECT_DOUBLE_EQ(0.333251953125, fp16_to_fp32(make_fp16(0x3555)));
27 }
28
29 TEST(FP16Test, RoundToNearestEven) {
30         ASSERT_DOUBLE_EQ(1.0, fp16_to_fp32(make_fp16(0x3c00)));
31
32         double x0 = fp16_to_fp32(make_fp16(0x3c00));
33         double x1 = fp16_to_fp32(make_fp16(0x3c01));
34         double x2 = fp16_to_fp32(make_fp16(0x3c02));
35         double x3 = fp16_to_fp32(make_fp16(0x3c03));
36         double x4 = fp16_to_fp32(make_fp16(0x3c04));
37
38         EXPECT_EQ(0x3c00, fp32_to_fp16(0.5 * (x0 + x1)).val);
39         EXPECT_EQ(0x3c02, fp32_to_fp16(0.5 * (x1 + x2)).val);
40         EXPECT_EQ(0x3c02, fp32_to_fp16(0.5 * (x2 + x3)).val);
41         EXPECT_EQ(0x3c04, fp32_to_fp16(0.5 * (x3 + x4)).val);
42 }
43
44 union fp64 {
45         double f;
46         unsigned long long ll;
47 };
48
49 #ifdef __F16C__
50 union fp32 {
51         float f;
52         unsigned int u;
53 };
54 #endif
55
56 TEST(FP16Test, NaN) {
57         // Ignore the sign bit.
58         EXPECT_EQ(0x7e00, fp32_to_fp16(0.0 / 0.0).val & 0x7fff);
59         EXPECT_TRUE(std::isnan(fp16_to_fp32(make_fp16(0xfe00))));
60
61         fp32 borderline_inf;
62         borderline_inf.u = 0x7f800000ull;
63         fp32 borderline_nan;
64         borderline_nan.u = 0x7f800001ull;
65
66         ASSERT_FALSE(std::isfinite(borderline_inf.f));
67         ASSERT_FALSE(std::isnan(borderline_inf.f));
68
69         ASSERT_FALSE(std::isfinite(borderline_nan.f));
70         ASSERT_TRUE(std::isnan(borderline_nan.f));
71
72         double borderline_inf_roundtrip = fp16_to_fp32(fp32_to_fp16(borderline_inf.f));
73         double borderline_nan_roundtrip = fp16_to_fp32(fp32_to_fp16(borderline_nan.f));
74
75         EXPECT_FALSE(std::isfinite(borderline_inf_roundtrip));
76         EXPECT_FALSE(std::isnan(borderline_inf_roundtrip));
77
78         EXPECT_FALSE(std::isfinite(borderline_nan_roundtrip));
79         EXPECT_TRUE(std::isnan(borderline_nan_roundtrip));
80 }
81
82 TEST(FP16Test, Denormals) {
83         const double smallest_fp16_denormal = 5.9604644775390625e-08;
84         EXPECT_EQ(0x0001, fp32_to_fp16(smallest_fp16_denormal).val);
85         EXPECT_EQ(0x0000, fp32_to_fp16(0.5 * smallest_fp16_denormal).val);  // Round-to-even.
86         EXPECT_EQ(0x0001, fp32_to_fp16(0.51 * smallest_fp16_denormal).val);
87         EXPECT_EQ(0x0002, fp32_to_fp16(1.5 * smallest_fp16_denormal).val);
88
89         const double smallest_fp16_non_denormal = 6.103515625e-05;
90         EXPECT_EQ(0x0400, fp32_to_fp16(smallest_fp16_non_denormal).val);
91         EXPECT_EQ(0x0400, fp32_to_fp16(smallest_fp16_non_denormal - 0.5 * smallest_fp16_denormal).val);  // Round-to-even.
92         EXPECT_EQ(0x03ff, fp32_to_fp16(smallest_fp16_non_denormal - smallest_fp16_denormal).val);
93 }
94
95 }  // namespace movit