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/*
* 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 compiler optimizations.
volatile float f = 1.968750f;
volatile float m = 0x1.0p23f;
volatile float x = f + m;
ASSERT_FLOAT_EQ(expectation1, x);
x = x - m;
ASSERT_EQ(expectation2, x);
}
static void DivideByZero() {
// volatile to prevent compiler optimizations.
volatile float zero = 0.0f;
volatile float result __attribute__((unused)) = 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) {
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));
}
TEST(fenv, feenableexcept_fegetexcept) {
#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) {
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
}