1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <gtest/gtest.h>
18
19 #include "utils.h"
20
21 #include <fenv.h>
22 #include <stdint.h>
23 #include <sys/cdefs.h>
24
TestRounding(float expectation1,float expectation2)25 static void TestRounding(float expectation1, float expectation2) {
26 // Volatile to prevent compile-time evaluation.
27 volatile float f = 1.968750f;
28 volatile float m = 0x1.0p23f;
29 float x;
30 DoNotOptimize(x = f + m);
31 ASSERT_FLOAT_EQ(expectation1, x);
32 DoNotOptimize(x = x - m);
33 ASSERT_EQ(expectation2, x);
34 }
35
DivideByZero()36 static void DivideByZero() {
37 // Volatile to prevent compile-time evaluation.
38 volatile float zero = 0.0f;
39 DoNotOptimize(123.0f / zero);
40 }
41
TEST(fenv,fesetround_fegetround_FE_TONEAREST)42 TEST(fenv, fesetround_fegetround_FE_TONEAREST) {
43 fesetround(FE_TONEAREST);
44 ASSERT_EQ(FE_TONEAREST, fegetround());
45 TestRounding(8388610.0f, 2.0f);
46 }
47
TEST(fenv,fesetround_fegetround_FE_TOWARDZERO)48 TEST(fenv, fesetround_fegetround_FE_TOWARDZERO) {
49 fesetround(FE_TOWARDZERO);
50 ASSERT_EQ(FE_TOWARDZERO, fegetround());
51 TestRounding(8388609.0f, 1.0f);
52 }
53
TEST(fenv,fesetround_fegetround_FE_UPWARD)54 TEST(fenv, fesetround_fegetround_FE_UPWARD) {
55 fesetround(FE_UPWARD);
56 ASSERT_EQ(FE_UPWARD, fegetround());
57 TestRounding(8388610.0f, 2.0f);
58 }
59
TEST(fenv,fesetround_fegetround_FE_DOWNWARD)60 TEST(fenv, fesetround_fegetround_FE_DOWNWARD) {
61 fesetround(FE_DOWNWARD);
62 ASSERT_EQ(FE_DOWNWARD, fegetround());
63 TestRounding(8388609.0f, 1.0f);
64 }
65
TEST(fenv,feclearexcept_fetestexcept)66 TEST(fenv, feclearexcept_fetestexcept) {
67 // Clearing clears.
68 feclearexcept(FE_ALL_EXCEPT);
69 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
70
71 // Dividing by zero sets FE_DIVBYZERO.
72 DivideByZero();
73 int raised = fetestexcept(FE_DIVBYZERO | FE_OVERFLOW);
74 ASSERT_TRUE((raised & FE_OVERFLOW) == 0);
75 ASSERT_TRUE((raised & FE_DIVBYZERO) != 0);
76
77 // Clearing an unset bit is a no-op.
78 feclearexcept(FE_OVERFLOW);
79 ASSERT_TRUE((raised & FE_OVERFLOW) == 0);
80 ASSERT_TRUE((raised & FE_DIVBYZERO) != 0);
81
82 // Clearing a set bit works.
83 feclearexcept(FE_DIVBYZERO);
84 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
85 }
86
TEST(fenv,FE_DFL_ENV_macro)87 TEST(fenv, FE_DFL_ENV_macro) {
88 ASSERT_EQ(0, fesetenv(FE_DFL_ENV));
89 }
90
TEST(fenv,feraiseexcept)91 TEST(fenv, feraiseexcept) {
92 feclearexcept(FE_ALL_EXCEPT);
93 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
94
95 ASSERT_EQ(0, feraiseexcept(FE_DIVBYZERO | FE_OVERFLOW));
96 ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
97 }
98
TEST(fenv,fegetenv_fesetenv)99 TEST(fenv, fegetenv_fesetenv) {
100 // Set FE_OVERFLOW only.
101 feclearexcept(FE_ALL_EXCEPT);
102 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
103 ASSERT_EQ(0, feraiseexcept(FE_OVERFLOW));
104
105 // fegetenv (unlike feholdexcept) leaves the current state untouched...
106 fenv_t state;
107 ASSERT_EQ(0, fegetenv(&state));
108 ASSERT_EQ(FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
109
110 // Dividing by zero sets the appropriate flag...
111 DivideByZero();
112 ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
113
114 // And fesetenv (unlike feupdateenv) clobbers that to return to where
115 // we started.
116 ASSERT_EQ(0, fesetenv(&state));
117 ASSERT_EQ(FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
118 }
119
TEST(fenv,fegetenv_fesetenv_rounding_mode)120 TEST(fenv, fegetenv_fesetenv_rounding_mode) {
121 // Test that fegetenv()/fesetenv() includes the rounding mode.
122 fesetround(FE_DOWNWARD);
123 ASSERT_EQ(FE_DOWNWARD, fegetround());
124
125 fenv_t env;
126 fegetenv(&env);
127
128 fesetround(FE_UPWARD);
129 ASSERT_EQ(FE_UPWARD, fegetround());
130
131 fesetenv(&env);
132 ASSERT_EQ(FE_DOWNWARD, fegetround());
133 }
134
TEST(fenv,feholdexcept_feupdateenv)135 TEST(fenv, feholdexcept_feupdateenv) {
136 // Set FE_OVERFLOW only.
137 feclearexcept(FE_ALL_EXCEPT);
138 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
139 ASSERT_EQ(0, feraiseexcept(FE_OVERFLOW));
140
141 // feholdexcept (unlike fegetenv) clears everything...
142 fenv_t state;
143 ASSERT_EQ(0, feholdexcept(&state));
144 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
145
146 // Dividing by zero sets the appropriate flag...
147 DivideByZero();
148 ASSERT_EQ(FE_DIVBYZERO, fetestexcept(FE_ALL_EXCEPT));
149
150 // And feupdateenv (unlike fesetenv) merges what we started with
151 // (FE_OVERFLOW) with what we now have (FE_DIVBYZERO).
152 ASSERT_EQ(0, feupdateenv(&state));
153 ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW, fetestexcept(FE_ALL_EXCEPT));
154 }
155
TEST(fenv,fegetexceptflag_fesetexceptflag)156 TEST(fenv, fegetexceptflag_fesetexceptflag) {
157 // Set three flags.
158 feclearexcept(FE_ALL_EXCEPT);
159 ASSERT_EQ(0, feraiseexcept(FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW));
160 ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
161
162 fexcept_t all; // FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW
163 fexcept_t two; // FE_OVERFLOW | FE_UNDERFLOW
164 ASSERT_EQ(0, fegetexceptflag(&all, FE_ALL_EXCEPT));
165 ASSERT_EQ(0, fegetexceptflag(&two, FE_OVERFLOW | FE_UNDERFLOW));
166
167 // Check we can restore all.
168 feclearexcept(FE_ALL_EXCEPT);
169 ASSERT_EQ(0, fesetexceptflag(&all, FE_ALL_EXCEPT));
170 ASSERT_EQ(FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
171
172 // Check that `two` only stored a subset.
173 feclearexcept(FE_ALL_EXCEPT);
174 ASSERT_EQ(0, fesetexceptflag(&two, FE_ALL_EXCEPT));
175 ASSERT_EQ(FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
176
177 // Check that we can restore a single flag.
178 feclearexcept(FE_ALL_EXCEPT);
179 ASSERT_EQ(0, fesetexceptflag(&all, FE_DIVBYZERO));
180 ASSERT_EQ(FE_DIVBYZERO, fetestexcept(FE_ALL_EXCEPT));
181
182 // Check that we can restore a subset of flags.
183 feclearexcept(FE_ALL_EXCEPT);
184 ASSERT_EQ(0, fesetexceptflag(&all, FE_OVERFLOW | FE_UNDERFLOW));
185 ASSERT_EQ(FE_OVERFLOW | FE_UNDERFLOW, fetestexcept(FE_ALL_EXCEPT));
186 }
187
TEST(fenv,fedisableexcept_fegetexcept)188 TEST(fenv, fedisableexcept_fegetexcept) {
189 #if !defined(ANDROID_HOST_MUSL)
190 feclearexcept(FE_ALL_EXCEPT);
191 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
192
193 // No SIGFPE please...
194 ASSERT_EQ(0, fedisableexcept(FE_ALL_EXCEPT));
195 ASSERT_EQ(0, fegetexcept());
196 ASSERT_EQ(0, feraiseexcept(FE_INVALID));
197 ASSERT_EQ(FE_INVALID, fetestexcept(FE_ALL_EXCEPT));
198 #else
199 GTEST_SKIP() << "musl doesn't have fegetexcept";
200 #endif
201 }
202
TEST(fenv,feenableexcept_fegetexcept)203 TEST(fenv, feenableexcept_fegetexcept) {
204 #if !defined(ANDROID_HOST_MUSL)
205 #if defined(__aarch64__) || defined(__arm__) || defined(__riscv)
206 // ARM and RISC-V don't support hardware trapping of floating point
207 // exceptions. ARM used to if you go back far enough, but it was
208 // removed in the Cortex-A8 between r3p1 and r3p2. RISC-V never has.
209 ASSERT_EQ(-1, feenableexcept(FE_INVALID));
210 ASSERT_EQ(0, fegetexcept());
211 ASSERT_EQ(-1, feenableexcept(FE_DIVBYZERO));
212 ASSERT_EQ(0, fegetexcept());
213 ASSERT_EQ(-1, feenableexcept(FE_OVERFLOW));
214 ASSERT_EQ(0, fegetexcept());
215 ASSERT_EQ(-1, feenableexcept(FE_UNDERFLOW));
216 ASSERT_EQ(0, fegetexcept());
217 ASSERT_EQ(-1, feenableexcept(FE_INEXACT));
218 ASSERT_EQ(0, fegetexcept());
219 #if defined(_FE_DENORMAL) // riscv64 doesn't support this.
220 ASSERT_EQ(-1, feenableexcept(FE_DENORMAL));
221 ASSERT_EQ(0, fegetexcept());
222 #endif
223 #else
224 // We can't recover from SIGFPE, so sacrifice a child...
225 pid_t pid = fork();
226 ASSERT_NE(-1, pid) << strerror(errno);
227
228 if (pid == 0) {
229 signal(SIGFPE, SIG_DFL); // Disable debuggerd.
230 feclearexcept(FE_ALL_EXCEPT);
231 ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
232 ASSERT_EQ(0, feenableexcept(FE_INVALID));
233 ASSERT_EQ(FE_INVALID, fegetexcept());
234 ASSERT_EQ(0, feraiseexcept(FE_INVALID));
235 _exit(123);
236 }
237
238 AssertChildExited(pid, -SIGFPE);
239 #endif
240 #else
241 GTEST_SKIP() << "musl doesn't have fegetexcept";
242 #endif
243 }
244