Initial commit

module/jni/libcxx/benchmarks/formatter_float.bench.cpp

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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
+//
+//===----------------------------------------------------------------------===//
+
+#include <format>
+
+#include <array>
+#include <limits>
+#include <random>
+#include <string>
+
+#include "CartesianBenchmarks.h"
+#include "benchmark/benchmark.h"
+
+// *** Localization ***
+enum class LocalizationE { False, True };
+struct AllLocalizations : EnumValuesAsTuple<AllLocalizations, LocalizationE, 2> {
+  static constexpr const char* Names[] = {"LocFalse", "LocTrue"};
+};
+
+template <LocalizationE E>
+struct Localization {};
+
+template <>
+struct Localization<LocalizationE::False> {
+  static constexpr const char* fmt = "";
+};
+
+template <>
+struct Localization<LocalizationE::True> {
+  static constexpr const char* fmt = "L";
+};
+
+// *** Types ***
+enum class TypeE { Float, Double, LongDouble };
+// TODO FMT Set to 3 after to_chars has long double suport.
+struct AllTypes : EnumValuesAsTuple<AllTypes, TypeE, 2> {
+  static constexpr const char* Names[] = {"Float", "Double", "LongDouble"};
+};
+
+template <TypeE E>
+struct Type {};
+
+template <>
+struct Type<TypeE::Float> {
+  using type = float;
+};
+
+template <>
+struct Type<TypeE::Double> {
+  using type = double;
+};
+
+template <>
+struct Type<TypeE::LongDouble> {
+  using type = long double;
+};
+
+// *** Values ***
+enum class ValueE { Inf, Random };
+struct AllValues : EnumValuesAsTuple<AllValues, ValueE, 2> {
+  static constexpr const char* Names[] = {"Inf", "Random"};
+};
+
+template <ValueE E>
+struct Value {};
+
+template <>
+struct Value<ValueE::Inf> {
+  template <class F>
+  static std::array<F, 1000> make_data() {
+    std::array<F, 1000> result;
+    std::fill(result.begin(), result.end(), -std::numeric_limits<F>::infinity());
+    return result;
+  }
+};
+
+template <>
+struct Value<ValueE::Random> {
+  template <class F>
+  static std::array<F, 1000> make_data() {
+    std::random_device seed;
+    std::mt19937 generator(seed());
+    std::uniform_int_distribution<std::conditional_t<sizeof(F) == sizeof(uint32_t), uint32_t, uint64_t>> distribution;
+
+    std::array<F, 1000> result;
+    std::generate(result.begin(), result.end(), [&] {
+      while (true) {
+        auto result = std::bit_cast<F>(distribution(generator));
+        if (std::isfinite(result))
+          return result;
+      }
+    });
+    return result;
+  }
+};
+
+// *** Display Type ***
+enum class DisplayTypeE {
+  Default,
+  Hex,
+  Scientific,
+  Fixed,
+  General,
+};
+struct AllDisplayTypes : EnumValuesAsTuple<AllDisplayTypes, DisplayTypeE, 5> {
+  static constexpr const char* Names[] = {"DisplayDefault", "DisplayHex", "DisplayScientific", "DisplayFixed",
+                                          "DisplayGeneral"};
+};
+
+template <DisplayTypeE E>
+struct DisplayType {};
+
+template <>
+struct DisplayType<DisplayTypeE::Default> {
+  static constexpr const char* fmt = "";
+};
+
+template <>
+struct DisplayType<DisplayTypeE::Hex> {
+  static constexpr const char* fmt = "a";
+};
+
+template <>
+struct DisplayType<DisplayTypeE::Scientific> {
+  static constexpr const char* fmt = "e";
+};
+
+template <>
+struct DisplayType<DisplayTypeE::Fixed> {
+  static constexpr const char* fmt = "f";
+};
+
+template <>
+struct DisplayType<DisplayTypeE::General> {
+  static constexpr const char* fmt = "g";
+};
+
+// *** Alignment ***
+enum class AlignmentE { None, Left, Center, Right, ZeroPadding };
+struct AllAlignments : EnumValuesAsTuple<AllAlignments, AlignmentE, 5> {
+  static constexpr const char* Names[] = {"AlignNone", "AlignmentLeft", "AlignmentCenter", "AlignmentRight",
+                                          "ZeroPadding"};
+};
+
+template <AlignmentE E>
+struct Alignment {};
+
+template <>
+struct Alignment<AlignmentE::None> {
+  static constexpr const char* fmt = "";
+};
+
+template <>
+struct Alignment<AlignmentE::Left> {
+  // Width > PrecisionE::Huge
+  static constexpr const char* fmt = "0<17500";
+};
+
+template <>
+struct Alignment<AlignmentE::Center> {
+  // Width > PrecisionE::Huge
+  static constexpr const char* fmt = "0^17500";
+};
+
+template <>
+struct Alignment<AlignmentE::Right> {
+  // Width > PrecisionE::Huge
+  static constexpr const char* fmt = "0>17500";
+};
+
+template <>
+struct Alignment<AlignmentE::ZeroPadding> {
+  // Width > PrecisionE::Huge
+  static constexpr const char* fmt = "017500";
+};
+
+enum class PrecisionE { None, Zero, Small, Huge };
+struct AllPrecisions : EnumValuesAsTuple<AllPrecisions, PrecisionE, 4> {
+  static constexpr const char* Names[] = {"PrecNone", "PrecZero", "PrecSmall", "PrecHuge"};
+};
+
+template <PrecisionE E>
+struct Precision {};
+
+template <>
+struct Precision<PrecisionE::None> {
+  static constexpr const char* fmt = "";
+};
+
+template <>
+struct Precision<PrecisionE::Zero> {
+  static constexpr const char* fmt = ".0";
+};
+
+template <>
+struct Precision<PrecisionE::Small> {
+  static constexpr const char* fmt = ".10";
+};
+
+template <>
+struct Precision<PrecisionE::Huge> {
+  // The maximum precision for a minimal sub normal long double is ±0x1p-16494.
+  // This value is always larger than that value forcing the trailing zero path
+  // to be executed.
+  static constexpr const char* fmt = ".17000";
+};
+
+template <class L, class DT, class T, class V, class A, class P>
+struct FloatingPoint {
+  using F = typename Type<T::value>::type;
+
+  void run(benchmark::State& state) const {
+    std::array<F, 1000> data{Value<V::value>::template make_data<F>()};
+    std::array<char, 20'000> output;
+
+    while (state.KeepRunningBatch(1000))
+      for (F value : data)
+        benchmark::DoNotOptimize(std::format_to(output.begin(), std::string_view{fmt.data(), fmt.size()}, value));
+  }
+
+  std::string name() const {
+    return "FloatingPoint" + L::name() + DT::name() + T::name() + V::name() + A::name() + P::name();
+  }
+
+  static constexpr std::string make_fmt() {
+    return std::string("{:") + Alignment<A::value>::fmt + Precision<P::value>::fmt + Localization<L::value>::fmt +
+           DisplayType<DT::value>::fmt + "}";
+  }
+
+  static constexpr auto fmt = []() {
+    constexpr size_t s = make_fmt().size();
+    std::array<char, s> r;
+    std::ranges::copy(make_fmt(), r.begin());
+    return r;
+  }();
+};
+
+int main(int argc, char** argv) {
+  benchmark::Initialize(&argc, argv);
+  if (benchmark::ReportUnrecognizedArguments(argc, argv))
+    return 1;
+
+  makeCartesianProductBenchmark<FloatingPoint, AllLocalizations, AllDisplayTypes, AllTypes, AllValues, AllAlignments,
+                                AllPrecisions>();
+
+  benchmark::RunSpecifiedBenchmarks();
+}