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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14
#include <array>
#include <charconv>
#include <random>
#include "benchmark/benchmark.h"
#include "test_macros.h"
static const std::array<unsigned, 1000> input = [] {
std::mt19937 generator;
std::uniform_int_distribution<unsigned> distribution(0, std::numeric_limits<unsigned>::max());
std::array<unsigned, 1000> result;
std::generate_n(result.begin(), result.size(), [&] { return distribution(generator); });
return result;
}();
static void BM_to_chars_good(benchmark::State& state) {
char buffer[128];
int base = state.range(0);
while (state.KeepRunningBatch(input.size()))
for (auto value : input)
benchmark::DoNotOptimize(std::to_chars(buffer, &buffer[128], value, base));
}
BENCHMARK(BM_to_chars_good)->DenseRange(2, 36, 1);
static void BM_to_chars_bad(benchmark::State& state) {
char buffer[128];
int base = state.range(0);
struct sample {
unsigned size;
unsigned value;
};
std::array<sample, 1000> data;
// Assume the failure occurs, on average, halfway during the conversion.
std::transform(input.begin(), input.end(), data.begin(), [&](unsigned value) {
std::to_chars_result result = std::to_chars(buffer, &buffer[128], value, base);
return sample{unsigned((result.ptr - buffer) / 2), value};
});
while (state.KeepRunningBatch(data.size()))
for (auto element : data)
benchmark::DoNotOptimize(std::to_chars(buffer, &buffer[element.size], element.value, base));
}
BENCHMARK(BM_to_chars_bad)->DenseRange(2, 36, 1);
BENCHMARK_MAIN();
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