libcxx/test/benchmarks/format.bench.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11, c++14, c++17
  10
  11 #include <format>
  12
  13 #include <string>
  14
  15 #include "benchmark/benchmark.h"
  16 #include "make_string.h"
  17 #include "test_macros.h"
  18
  19 #define CSTR(S) MAKE_CSTRING(CharT, S)
  20
  21 template <class CharT>
  22 static void BM_format_string(benchmark::State& state) {
  23   size_t size = state.range(0);
  24   std::basic_string<CharT> str(size, CharT('*'));
  25
  26   while (state.KeepRunningBatch(str.size())) {
  27     std::basic_string<CharT> s = std::format(CSTR("{}"), str);
  28     benchmark::DoNotOptimize(s);
  29   }
  30
  31   state.SetBytesProcessed(state.iterations() * size * sizeof(CharT));
  32 }
  33 BENCHMARK(BM_format_string<char>)->RangeMultiplier(2)->Range(1, 1 << 20);
  34 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  35 BENCHMARK(BM_format_string<wchar_t>)->RangeMultiplier(2)->Range(1, 1 << 20);
  36 #endif
  37
  38 BENCHMARK_MAIN();