#include <cstdint>
#include <vector>
#include "absl/base/optimization.h"
#include "absl/numeric/bits.h"
#include "absl/random/random.h"
#include "benchmark/benchmark.h"
namespace absl {
namespace {
template <typename T>
static void BM_bit_width(benchmark::State& state) {
const auto count = static_cast<size_t>(state.range(0));
absl::BitGen rng;
std::vector<T> values;
values.reserve(count);
for (size_t i = 0; i < count; ++i) {
values.push_back(absl::Uniform<T>(rng, 0, std::numeric_limits<T>::max()));
}
while (state.KeepRunningBatch(static_cast<int64_t>(count))) {
for (size_t i = 0; i < count; ++i) {
benchmark::DoNotOptimize(absl::bit_width(values[i]));
}
}
}
BENCHMARK_TEMPLATE(BM_bit_width, uint8_t)->Range(1, 1 << 20);
BENCHMARK_TEMPLATE(BM_bit_width, uint16_t)->Range(1, 1 << 20);
BENCHMARK_TEMPLATE(BM_bit_width, uint32_t)->Range(1, 1 << 20);
BENCHMARK_TEMPLATE(BM_bit_width, uint64_t)->Range(1, 1 << 20);
template <typename T>
static void BM_bit_width_nonzero(benchmark::State& state) {
const auto count = static_cast<size_t>(state.range(0));
absl::BitGen rng;
std::vector<T> values;
values.reserve(count);
for (size_t i = 0; i < count; ++i) {
values.push_back(absl::Uniform<T>(rng, 1, std::numeric_limits<T>::max()));
}
while (state.KeepRunningBatch(static_cast<int64_t>(count))) {
for (size_t i = 0; i < count; ++i) {
const T value = values[i];
ABSL_ASSUME(value > 0);
benchmark::DoNotOptimize(absl::bit_width(value));
}
}
}
BENCHMARK_TEMPLATE(BM_bit_width_nonzero, uint8_t)->Range(1, 1 << 20);
BENCHMARK_TEMPLATE(BM_bit_width_nonzero, uint16_t)->Range(1, 1 << 20);
BENCHMARK_TEMPLATE(BM_bit_width_nonzero, uint32_t)->Range(1, 1 << 20);
BENCHMARK_TEMPLATE(BM_bit_width_nonzero, uint64_t)->Range(1, 1 << 20);
} }