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 fmodf return the correct values
10**
11** Dependencies: PAL_Initialize
12** PAL_Terminate
13** Fail
14** fabsf
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 sqrt(-1.0)
34#define PAL_POSINF -log(0.0)
35#define PAL_NEGINF log(0.0)
36
37/**
38 * Helper test structure
39 */
40struct test
41{
42 float numerator; /* second component of the value to test the function with */
43 float denominator; /* first component of the value to test the function with */
44 float expected; /* expected result */
45 float variance; /* maximum delta between the expected and actual result */
46};
47
48/**
49 * validate
50 *
51 * test validation function
52 */
53void __cdecl validate(float numerator, float denominator, float expected, float variance)
54{
55 float result = fmodf(numerator, denominator);
56
57 /*
58 * The test is valid when the difference between result
59 * and expected is less than or equal to variance
60 */
61 float delta = fabsf(result - expected);
62
63 if (delta > variance)
64 {
65 Fail("fmodf(%g, %g) returned %10.9g when it should have returned %10.9g",
66 numerator, denominator, result, expected);
67 }
68}
69
70/**
71 * validate
72 *
73 * test validation function for values returning NaN
74 */
75void __cdecl validate_isnan(float numerator, float denominator)
76{
77 float result = fmodf(numerator, denominator);
78
79 if (!_isnan(result))
80 {
81 Fail("fmodf(%g, %g) returned %10.9g when it should have returned %10.9g",
82 numerator, denominator, result, PAL_NAN);
83 }
84}
85
86/**
87 * main
88 *
89 * executable entry point
90 */
91INT __cdecl main(INT argc, CHAR **argv)
92{
93 struct test tests[] =
94 {
95 /* numerator denominator expected variance */
96 { 0, PAL_POSINF, 0, PAL_EPSILON },
97 { 0.312961796f, 0.949765715f, 0.312961796f, PAL_EPSILON },
98 { 0.420770483f, 0.907167129f, 0.420770483f, PAL_EPSILON },
99 { 0.594480769f, 0.804109828f, 0.594480769f, PAL_EPSILON },
100 { 0.638961276f, 0.769238901f, 0.638961276f, PAL_EPSILON },
101 { 0.649636939f, 0.760244597f, 0.649636939f, PAL_EPSILON },
102 { 0.707106781f, 0.707106781f, 0, PAL_EPSILON },
103 { 1, 1, 0, PAL_EPSILON },
104 { 0.841470985f, 0.540302306f, 0.301168679f, PAL_EPSILON },
105 { 0.903719457f, 0.428125148f, 0.0474691617f, PAL_EPSILON / 10 },
106 { 0.987765946f, 0.155943695f, 0.0521037774f, PAL_EPSILON / 10 },
107 { 0.991806244f, 0.127751218f, 0.0975477216f, PAL_EPSILON / 10 },
108 { 0.743980337f, -0.668201510f, 0.0757788268f, PAL_EPSILON / 10 },
109 { 0.410781291f, -0.911733915f, 0.410781291f, PAL_EPSILON },
110 { 0, -1, 0, PAL_EPSILON },
111 { 1, PAL_POSINF, 1, PAL_EPSILON * 10 },
112 };
113
114
115 // PAL initialization
116 if (PAL_Initialize(argc, argv) != 0)
117 {
118 return FAIL;
119 }
120
121 for (int i = 0; i < (sizeof(tests) / sizeof(struct test)); i++)
122 {
123 validate( tests[i].numerator, tests[i].denominator, tests[i].expected, tests[i].variance);
124 validate(-tests[i].numerator, tests[i].denominator, -tests[i].expected, tests[i].variance);
125 validate( tests[i].numerator, -tests[i].denominator, tests[i].expected, tests[i].variance);
126 validate(-tests[i].numerator, -tests[i].denominator, -tests[i].expected, tests[i].variance);
127 }
128
129 validate_isnan( 0, 0);
130 validate_isnan(-0.0f, 0);
131 validate_isnan( 0, -0.0f);
132 validate_isnan(-0.0f, -0.0f);
133
134 validate_isnan( 1, 0);
135 validate_isnan(-1, 0);
136 validate_isnan( 1, -0.0f);
137 validate_isnan(-1, -0.0f);
138
139 validate_isnan(PAL_POSINF, PAL_POSINF);
140 validate_isnan(PAL_NEGINF, PAL_POSINF);
141 validate_isnan(PAL_POSINF, PAL_NEGINF);
142 validate_isnan(PAL_NEGINF, PAL_NEGINF);
143
144 validate_isnan(PAL_POSINF, 0);
145 validate_isnan(PAL_NEGINF, 0);
146 validate_isnan(PAL_POSINF, -0.0f);
147 validate_isnan(PAL_NEGINF, -0.0f);
148
149 validate_isnan(PAL_POSINF, 1);
150 validate_isnan(PAL_NEGINF, 1);
151 validate_isnan(PAL_POSINF, -1);
152 validate_isnan(PAL_NEGINF, -1);
153
154 PAL_Terminate();
155 return PASS;
156}
157