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https://github.com/Gericom/teak-llvm.git
synced 2025-06-21 04:25:45 -04:00
ef915d3ef4
This patch fixes a performance bug when constructing or appending to a path from a string or c-string. Previously we called 'push_back' to append every single character. This caused multiple re-allocation and copies when at most one reallocation is necessary. The new behavior is to simply call `string::append` so it can correctly handle reallocation. For large strings this change is a ~4x improvement. This also makes our path faster to construct than libstdc++'s. llvm-svn: 285530
105 lines
2.7 KiB
C++
105 lines
2.7 KiB
C++
#include <experimental/filesystem>
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#include "benchmark/benchmark_api.h"
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#include "GenerateInput.hpp"
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namespace fs = std::experimental::filesystem;
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static const size_t TestNumInputs = 1024;
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template <class GenInputs>
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void BM_PathConstructString(benchmark::State &st, GenInputs gen) {
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using namespace fs;
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const auto in = gen(st.range(0));
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path PP;
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for (auto& Part : in)
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PP /= Part;
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benchmark::DoNotOptimize(PP.native().data());
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while (st.KeepRunning()) {
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const path P(PP.native());
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benchmark::DoNotOptimize(P.native().data());
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}
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}
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BENCHMARK_CAPTURE(BM_PathConstructString, large_string,
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getRandomStringInputs)->Arg(TestNumInputs);
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template <class GenInputs>
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void BM_PathConstructCStr(benchmark::State &st, GenInputs gen) {
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using namespace fs;
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const auto in = gen(st.range(0));
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path PP;
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for (auto& Part : in)
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PP /= Part;
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benchmark::DoNotOptimize(PP.native().data());
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while (st.KeepRunning()) {
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const path P(PP.native().c_str());
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benchmark::DoNotOptimize(P.native().data());
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}
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}
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BENCHMARK_CAPTURE(BM_PathConstructCStr, large_string,
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getRandomStringInputs)->Arg(TestNumInputs);
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template <class GenInputs>
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void BM_PathIterateMultipleTimes(benchmark::State &st, GenInputs gen) {
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using namespace fs;
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const auto in = gen(st.range(0));
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path PP;
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for (auto& Part : in)
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PP /= Part;
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benchmark::DoNotOptimize(PP.native().data());
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while (st.KeepRunning()) {
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for (auto &E : PP) {
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benchmark::DoNotOptimize(E.native().data());
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}
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benchmark::ClobberMemory();
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}
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}
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BENCHMARK_CAPTURE(BM_PathIterateMultipleTimes, iterate_elements,
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getRandomStringInputs)->Arg(TestNumInputs);
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template <class GenInputs>
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void BM_PathIterateOnce(benchmark::State &st, GenInputs gen) {
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using namespace fs;
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const auto in = gen(st.range(0));
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path PP;
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for (auto& Part : in)
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PP /= Part;
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benchmark::DoNotOptimize(PP.native().data());
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while (st.KeepRunning()) {
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const path P = PP.native();
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for (auto &E : P) {
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benchmark::DoNotOptimize(E.native().data());
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}
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benchmark::ClobberMemory();
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}
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}
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BENCHMARK_CAPTURE(BM_PathIterateOnce, iterate_elements,
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getRandomStringInputs)->Arg(TestNumInputs);
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template <class GenInputs>
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void BM_PathIterateOnceBackwards(benchmark::State &st, GenInputs gen) {
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using namespace fs;
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const auto in = gen(st.range(0));
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path PP;
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for (auto& Part : in)
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PP /= Part;
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benchmark::DoNotOptimize(PP.native().data());
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while (st.KeepRunning()) {
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const path P = PP.native();
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const auto B = P.begin();
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auto I = P.end();
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while (I != B) {
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--I;
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benchmark::DoNotOptimize(*I);
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}
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benchmark::DoNotOptimize(*I);
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}
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}
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BENCHMARK_CAPTURE(BM_PathIterateOnceBackwards, iterate_elements,
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getRandomStringInputs)->Arg(TestNumInputs);
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BENCHMARK_MAIN()
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