1// Licensed to the .NET Foundation under one or more agreements.
2// The .NET Foundation licenses this file to you under the MIT license.
3// See the LICENSE file in the project root for more information.
4
5/*=============================================================================
6**
7** Source: test1.c
8**
9** Purpose: Test to ensure that tanhf return the correct values
10**
11** Dependencies: PAL_Initialize
12** PAL_Terminate
13** Fail
14** fabs
15**
16**===========================================================================*/
17
18#include <palsuite.h>
19
20// binary32 (float) has a machine epsilon of 2^-23 (approx. 1.19e-07). However, this
21// is slightly too accurate when writing tests meant to run against libm implementations
22// for various platforms. 2^-21 (approx. 4.76e-07) seems to be as accurate as we can get.
23//
24// The tests themselves will take PAL_EPSILON and adjust it according to the expected result
25// so that the delta used for comparison will compare the most significant digits and ignore
26// any digits that are outside the double precision range (6-9 digits).
27
28// For example, a test with an expect result in the format of 0.xxxxxxxxx will use PAL_EPSILON
29// for the variance, while an expected result in the format of 0.0xxxxxxxxx will use
30// PAL_EPSILON / 10 and and expected result in the format of x.xxxxxx will use PAL_EPSILON * 10.
31#define PAL_EPSILON 4.76837158e-07
32
33#define PAL_NAN sqrtf(-1.0f)
34#define PAL_POSINF -logf(0.0f)
35#define PAL_NEGINF logf(0.0f)
36
37/**
38 * Helper test structure
39 */
40struct test
41{
42 float value; /* value to test the function with */
43 float expected; /* expected result */
44 float variance; /* maximum delta between the expected and actual result */
45};
46
47/**
48 * validate
49 *
50 * test validation function
51 */
52void __cdecl validate(float value, float expected, float variance)
53{
54 float result = tanhf(value);
55
56 /*
57 * The test is valid when the difference between result
58 * and expected is less than or equal to variance
59 */
60 float delta = fabsf(result - expected);
61
62 if (delta > variance)
63 {
64 Fail("tanhf(%g) returned %10.9g when it should have returned %10.9g",
65 value, result, expected);
66 }
67}
68
69/**
70 * validate
71 *
72 * test validation function for values returning NaN
73 */
74void __cdecl validate_isnan(float value)
75{
76 float result = tanhf(value);
77
78 if (!_isnanf(result))
79 {
80 Fail("tanhf(%g) returned %10.9g when it should have returned %10.9g",
81 value, result, PAL_NAN);
82 }
83}
84
85/**
86 * main
87 *
88 * executable entry point
89 */
90int __cdecl main(int argc, char **argv)
91{
92 struct test tests[] =
93 {
94 /* value expected variance */
95 { 0, 0, PAL_EPSILON },
96 { 0.318309886f, 0.307977913f, PAL_EPSILON }, // value: 1 / pi
97 { 0.434294482f, 0.408904012f, PAL_EPSILON }, // value: log10f(e)
98 { 0.636619772f, 0.562593600f, PAL_EPSILON }, // value: 2 / pi
99 { 0.693147181f, 0.6f, PAL_EPSILON }, // value: ln(2)
100 { 0.707106781f, 0.608859365f, PAL_EPSILON }, // value: 1 / sqrtf(2)
101 { 0.785398163f, 0.655794203f, PAL_EPSILON }, // value: pi / 4
102 { 1, 0.761594156f, PAL_EPSILON },
103 { 1.12837917f, 0.810463806f, PAL_EPSILON }, // value: 2 / sqrtf(pi)
104 { 1.41421356f, 0.888385562f, PAL_EPSILON }, // value: sqrtf(2)
105 { 1.44269504f, 0.894238946f, PAL_EPSILON }, // value: logf2(e)
106 { 1.57079633f, 0.917152336f, PAL_EPSILON }, // value: pi / 2
107 { 2.30258509f, 0.980198020f, PAL_EPSILON }, // value: ln(10)
108 { 2.71828183f, 0.991328916f, PAL_EPSILON }, // value: e
109 { 3.14159265f, 0.996272076f, PAL_EPSILON }, // value: pi
110 { PAL_POSINF, 1, PAL_EPSILON * 10 }
111 };
112
113 /* PAL initialization */
114 if (PAL_Initialize(argc, argv) != 0)
115 {
116 return FAIL;
117 }
118
119 for (int i = 0; i < (sizeof(tests) / sizeof(struct test)); i++)
120 {
121 validate( tests[i].value, tests[i].expected, tests[i].variance);
122 validate(-tests[i].value, -tests[i].expected, tests[i].variance);
123 }
124
125 validate_isnan(PAL_NAN);
126
127 PAL_Terminate();
128 return PASS;
129}
130