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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <gtest/gtest.h>
#include "utils.h"
#include <fenv.h>
#include <stdint.h>
static void TestRounding(float expectation1, float expectation2) {
// Volatile to prevent compile-time evaluation.
volatile float f = 1.968750f;
volatile float m = 0x1.0p23f;
float x;
DoNotOptimize(x = f + m);
ASSERT_FLOAT_EQ(expectation1, x);
DoNotOptimize(x = x - m);
ASSERT_EQ(expectation2, x);
}
static void DivideByZero() {
// Volatile to prevent compile-time evaluation.
volatile float zero = 0.0f;
DoNotOptimize(123.0f / zero);
}
TEST(fenv, fesetround_fegetround_FE_TONEAREST) {
fesetround(FE_TONEAREST);
ASSERT_EQ(FE_TONEAREST, fegetround());
TestRounding(8388610.0f, 2.0f);
}
TEST(fenv, fesetround_fegetround_FE_TOWARDZERO) {
fesetround(FE_TOWARDZERO);
ASSERT_EQ(FE_TOWARDZERO, fegetround());
TestRounding(8388609.0f, 1.0f);
}
TEST(fenv, fesetround_fegetround_FE_UPWARD) {
fesetround(FE_UPWARD);
ASSERT_EQ(FE_UPWARD, fegetround());
TestRounding(8388610.0f, 2.0f);
}
TEST(fenv, fesetround_fegetround_FE_DOWNWARD) {
fesetround(FE_DOWNWARD);
ASSERT_EQ(FE_DOWNWARD, fegetround());
TestRounding(8388609.0f, 1.0f);
}
TEST(fenv, feclearexcept_fetestexcept) {
// Clearing clears.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
// Dividing by zero sets FE_DIVBYZERO.
DivideByZero();
int raised = fetestexcept(FE_DIVBYZERO | FE_OVERFLOW);
ASSERT_TRUE((raised & FE_OVERFLOW) == 0);
ASSERT_TRUE((raised & FE_DIVBYZERO) != 0);
// Clearing an unset bit is a no-op.
feclearexcept(FE_OVERFLOW);
ASSERT_TRUE((raised & FE_OVERFLOW) == 0);
ASSERT_TRUE((raised & FE_DIVBYZERO) != 0);
// Clearing a set bit works.
feclearexcept(FE_DIVBYZERO);
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
}
TEST(fenv, FE_DFL_ENV_macro) {
ASSERT_EQ(0, fesetenv(FE_DFL_ENV));
}
TEST(fenv, feraiseexcept) {
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
ASSERT_EQ(0, feraiseexcept(FE_DIVBYZERO | FE_OVERFLOW));
ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
}
TEST(fenv, fegetenv_fesetenv) {
// Set FE_OVERFLOW only.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
ASSERT_EQ(0, feraiseexcept(FE_OVERFLOW));
// fegetenv (unlike feholdexcept) leaves the current state untouched...
fenv_t state;
ASSERT_EQ(0, fegetenv(&state));
ASSERT_EQ(FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
// Dividing by zero sets the appropriate flag...
DivideByZero();
ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
// And fesetenv (unlike feupdateenv) clobbers that to return to where
// we started.
ASSERT_EQ(0, fesetenv(&state));
ASSERT_EQ(FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
}
TEST(fenv, feholdexcept_feupdateenv) {
// Set FE_OVERFLOW only.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
ASSERT_EQ(0, feraiseexcept(FE_OVERFLOW));
// feholdexcept (unlike fegetenv) clears everything...
fenv_t state;
ASSERT_EQ(0, feholdexcept(&state));
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
// Dividing by zero sets the appropriate flag...
DivideByZero();
ASSERT_EQ(FE_DIVBYZERO, fetestexcept(FE_ALL_EXCEPT));
// And feupdateenv (unlike fesetenv) merges what we started with
// (FE_OVERFLOW) with what we now have (FE_DIVBYZERO).
ASSERT_EQ(0, feupdateenv(&state));
ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
}
TEST(fenv, fegetexceptflag_fesetexceptflag) {
// Set three flags.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, feraiseexcept(FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW));
ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
fexcept_t all; // FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW
fexcept_t two; // FE_OVERFLOW | FE_UNDERFLOW
ASSERT_EQ(0, fegetexceptflag(&all, FE_ALL_EXCEPT));
ASSERT_EQ(0, fegetexceptflag(&two, FE_OVERFLOW | FE_UNDERFLOW));
// Check we can restore all.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fesetexceptflag(&all, FE_ALL_EXCEPT));
ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
// Check that `two` only stored a subset.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fesetexceptflag(&two, FE_ALL_EXCEPT));
ASSERT_EQ(FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
// Check that we can restore a single flag.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fesetexceptflag(&all, FE_DIVBYZERO));
ASSERT_EQ(FE_DIVBYZERO, fetestexcept(FE_ALL_EXCEPT));
// Check that we can restore a subset of flags.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fesetexceptflag(&all, FE_OVERFLOW | FE_UNDERFLOW));
ASSERT_EQ(FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
}
TEST(fenv, fedisableexcept_fegetexcept) {
#if !defined(MUSL)
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
// No SIGFPE please...
ASSERT_EQ(0, fedisableexcept(FE_ALL_EXCEPT));
ASSERT_EQ(0, fegetexcept());
ASSERT_EQ(0, feraiseexcept(FE_INVALID));
ASSERT_EQ(FE_INVALID, fetestexcept(FE_ALL_EXCEPT));
#else
GTEST_SKIP() << "musl doesn't have fegetexcept";
#endif
}
TEST(fenv, feenableexcept_fegetexcept) {
#if !defined(MUSL)
#if defined(__aarch64__) || defined(__arm__)
// ARM doesn't support this. They used to if you go back far enough, but it was removed in
// the Cortex-A8 between r3p1 and r3p2.
ASSERT_EQ(-1, feenableexcept(FE_INVALID));
ASSERT_EQ(0, fegetexcept());
ASSERT_EQ(-1, feenableexcept(FE_DIVBYZERO));
ASSERT_EQ(0, fegetexcept());
ASSERT_EQ(-1, feenableexcept(FE_OVERFLOW));
ASSERT_EQ(0, fegetexcept());
ASSERT_EQ(-1, feenableexcept(FE_UNDERFLOW));
ASSERT_EQ(0, fegetexcept());
ASSERT_EQ(-1, feenableexcept(FE_INEXACT));
ASSERT_EQ(0, fegetexcept());
ASSERT_EQ(-1, feenableexcept(FE_DENORMAL));
ASSERT_EQ(0, fegetexcept());
#else
// We can't recover from SIGFPE, so sacrifice a child...
pid_t pid = fork();
ASSERT_NE(-1, pid) << strerror(errno);
if (pid == 0) {
signal(SIGFPE, SIG_DFL); // Disable debuggerd.
feclearexcept(FE_ALL_EXCEPT);
ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
ASSERT_EQ(0, feenableexcept(FE_INVALID));
ASSERT_EQ(FE_INVALID, fegetexcept());
ASSERT_EQ(0, feraiseexcept(FE_INVALID));
_exit(123);
}
AssertChildExited(pid, -SIGFPE);
#endif
#else
GTEST_SKIP() << "musl doesn't have fegetexcept";
#endif
}
|
