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: Tests ceil with simple positive and negative values. Also tests
10** extreme cases like extremely small values and positive and
11** negative infinity. Makes sure that calling ceil on NaN returns
12** NaN
13**
14**==========================================================================*/
15
16#include <palsuite.h>
17
18// binary64 (double) has a machine epsilon of 2^-52 (approx. 2.22e-16). However, this
19// is slightly too accurate when writing tests meant to run against libm implementations
20// for various platforms. 2^-50 (approx. 8.88e-16) seems to be as accurate as we can get.
21//
22// The tests themselves will take PAL_EPSILON and adjust it according to the expected result
23// so that the delta used for comparison will compare the most significant digits and ignore
24// any digits that are outside the double precision range (15-17 digits).
25
26// For example, a test with an expect result in the format of 0.xxxxxxxxxxxxxxxxx will use
27// PAL_EPSILON for the variance, while an expected result in the format of 0.0xxxxxxxxxxxxxxxxx
28// will use PAL_EPSILON / 10 and and expected result in the format of x.xxxxxxxxxxxxxxxx will
29// use PAL_EPSILON * 10.
30#define PAL_EPSILON 8.8817841970012523e-16
31
32#define PAL_NAN sqrt(-1.0)
33#define PAL_POSINF -log(0.0)
34#define PAL_NEGINF log(0.0)
35
36/**
37 * Helper test structure
38 */
39struct test
40{
41 double value; /* value to test the function with */
42 double expected; /* expected result */
43 double variance; /* maximum delta between the expected and actual result */
44};
45
46/**
47 * validate
48 *
49 * test validation function
50 */
51void __cdecl validate(double value, double expected, double variance)
52{
53 double result = ceil(value);
54
55 /*
56 * The test is valid when the difference between result
57 * and expected is less than or equal to variance
58 */
59 double delta = fabs(result - expected);
60
61 if (delta > variance)
62 {
63 Fail("ceil(%g) returned %20.17g when it should have returned %20.17g",
64 value, result, expected);
65 }
66}
67
68/**
69 * validate
70 *
71 * test validation function for values returning NaN
72 */
73void __cdecl validate_isnan(double value)
74{
75 double result = ceil(value);
76
77 if (!_isnan(result))
78 {
79 Fail("ceil(%g) returned %20.17g when it should have returned %20.17g",
80 value, result, PAL_NAN);
81 }
82}
83
84/**
85 * main
86 *
87 * executable entry point
88 */
89int __cdecl main(int argc, char *argv[])
90{
91 struct test tests[] =
92 {
93 /* value expected variance */
94 { 0.31830988618379067, 1, PAL_EPSILON * 10 }, // value: 1 / pi
95 { 0.43429448190325183, 1, PAL_EPSILON * 10 }, // value: log10(e)
96 { 0.63661977236758134, 1, PAL_EPSILON * 10 }, // value: 2 / pi
97 { 0.69314718055994531, 1, PAL_EPSILON * 10 }, // value: ln(2)
98 { 0.70710678118654752, 1, PAL_EPSILON * 10 }, // value: 1 / sqrt(2)
99 { 0.78539816339744831, 1, PAL_EPSILON * 10 }, // value: pi / 4
100 { 1.1283791670955126, 2, PAL_EPSILON * 10 }, // value: 2 / sqrt(pi)
101 { 1.4142135623730950, 2, PAL_EPSILON * 10 }, // value: sqrt(2)
102 { 1.4426950408889634, 2, PAL_EPSILON * 10 }, // value: log2(e)
103 { 1.5707963267948966, 2, PAL_EPSILON * 10 }, // value: pi / 2
104 { 2.3025850929940457, 3, PAL_EPSILON * 10 }, // value: ln(10)
105 { 2.7182818284590452, 3, PAL_EPSILON * 10 }, // value: e
106 { 3.1415926535897932, 4, PAL_EPSILON * 10 }, // value: pi
107 { PAL_POSINF, PAL_POSINF, 0 }
108 };
109
110 /* PAL initialization */
111 if (PAL_Initialize(argc, argv) != 0)
112 {
113 return FAIL;
114 }
115
116 validate( 0, 0, PAL_EPSILON);
117 validate(-0.0, 0, PAL_EPSILON);
118
119 validate( 1, 1, PAL_EPSILON * 10);
120 validate(-1.0, -1, PAL_EPSILON * 10);
121
122 for (int i = 0; i < (sizeof(tests) / sizeof(struct test)); i++)
123 {
124 validate( tests[i].value, tests[i].expected, tests[i].variance);
125 validate(-tests[i].value, 1 - tests[i].expected, tests[i].variance);
126 }
127
128 validate_isnan(PAL_NAN);
129
130 PAL_Terminate();
131 return PASS;
132}
133