blob: d4f1028dbd3c609e6f571f2c0038c030476864ce [file] [log] [blame]
// Copyright 2017 Google Inc. All Rights Reserved.
//
// 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
//
// https://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 "absl/random/internal/nanobenchmark.h"
#include "absl/log/check.h"
#include "absl/log/log.h"
#include "absl/strings/numbers.h"
#include "absl/strings/str_format.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace random_internal_nanobenchmark {
namespace {
uint64_t Div(const void*, FuncInput in) {
// Here we're measuring the throughput because benchmark invocations are
// independent.
const int64_t d1 = 0xFFFFFFFFFFll / int64_t(in); // IDIV
return d1;
}
template <size_t N>
void MeasureDiv(const FuncInput (&inputs)[N]) {
Result results[N];
Params params;
params.max_evals = 6; // avoid test timeout
const size_t num_results = Measure(&Div, nullptr, inputs, N, results, params);
if (num_results == 0) {
LOG(WARNING)
<< "WARNING: Measurement failed, should not happen when using "
"PinThreadToCPU unless the region to measure takes > 1 second.";
return;
}
for (size_t i = 0; i < num_results; ++i) {
LOG(INFO) << absl::StreamFormat("%5u: %6.2f ticks; MAD=%4.2f%%\n",
results[i].input, results[i].ticks,
results[i].variability * 100.0);
CHECK_NE(results[i].ticks, 0.0f) << "Zero duration";
}
}
void RunAll(const int argc, char* argv[]) {
// Avoid migrating between cores - important on multi-socket systems.
int cpu = -1;
if (argc == 2) {
if (!absl::SimpleAtoi(argv[1], &cpu)) {
LOG(FATAL) << "The optional argument must be a CPU number >= 0.";
}
}
PinThreadToCPU(cpu);
// unpredictable == 1 but the compiler doesn't know that.
const FuncInput unpredictable = argc != 999;
static const FuncInput inputs[] = {unpredictable * 10, unpredictable * 100};
MeasureDiv(inputs);
}
} // namespace
} // namespace random_internal_nanobenchmark
ABSL_NAMESPACE_END
} // namespace absl
int main(int argc, char* argv[]) {
absl::random_internal_nanobenchmark::RunAll(argc, argv);
return 0;
}