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Diffstat (limited to 'include/internal/benchmark/catch_optimizer.hpp')
-rw-r--r-- | include/internal/benchmark/catch_optimizer.hpp | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/include/internal/benchmark/catch_optimizer.hpp b/include/internal/benchmark/catch_optimizer.hpp new file mode 100644 index 00000000..bda7c6d7 --- /dev/null +++ b/include/internal/benchmark/catch_optimizer.hpp @@ -0,0 +1,68 @@ +/* + * Created by Joachim on 16/04/2019. + * Adapted from donated nonius code. + * + * Distributed under the Boost Software License, Version 1.0. (See accompanying + * file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + */ + + // Hinting the optimizer + +#ifndef TWOBLUECUBES_CATCH_OPTIMIZER_HPP_INCLUDED +#define TWOBLUECUBES_CATCH_OPTIMIZER_HPP_INCLUDED + +#if defined(_MSC_VER) +# include <atomic> // atomic_thread_fence +#endif + +namespace Catch { + namespace Benchmark { +#if defined(__GNUC__) || defined(__clang__) + template <typename T> + inline void keep_memory(T* p) { + asm volatile("" : : "g"(p) : "memory"); + } + inline void keep_memory() { + asm volatile("" : : : "memory"); + } + + namespace Detail { + inline void optimizer_barrier() { keep_memory(); } + } // namespace Detail +#elif defined(_MSC_VER) + +#pragma optimize("", off) + template <typename T> + inline void keep_memory(T* p) { + // thanks @milleniumbug + *reinterpret_cast<char volatile*>(p) = *reinterpret_cast<char const volatile*>(p); + } + // TODO equivalent keep_memory() +#pragma optimize("", on) + + namespace Detail { + inline void optimizer_barrier() { + std::atomic_thread_fence(std::memory_order_seq_cst); + } + } // namespace Detail + +#endif + + template <typename T> + inline void deoptimize_value(T&& x) { + keep_memory(&x); + } + + template <typename Fn, typename... Args> + inline auto invoke_deoptimized(Fn&& fn, Args&&... args) -> typename std::enable_if<!std::is_same<void, decltype(fn(args...))>::value>::type { + deoptimize_value(std::forward<Fn>(fn) (std::forward<Args...>(args...))); + } + + template <typename Fn, typename... Args> + inline auto invoke_deoptimized(Fn&& fn, Args&&... args) -> typename std::enable_if<std::is_same<void, decltype(fn(args...))>::value>::type { + std::forward<Fn>(fn) (std::forward<Args...>(args...)); + } + } // namespace Benchmark +} // namespace Catch + +#endif // TWOBLUECUBES_CATCH_OPTIMIZER_HPP_INCLUDED |