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Tsung-Wei HuangTsung-Wei Huang
Tsung-Wei Huang
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Tsung-Wei Huang
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added reduce example
1 parent 93ef312 commit 2768de5

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Lines changed: 384 additions & 78 deletions

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‎CMakeLists.txt‎

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@@ -63,6 +63,9 @@ target_link_libraries(debug ${EXAMPLE_EXE_LINKER_FLAGS})
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add_executable(emplace example/emplace.cpp)
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target_link_libraries(emplace ${EXAMPLE_EXE_LINKER_FLAGS})
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add_executable(reduce example/reduce.cpp)
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target_link_libraries(reduce ${EXAMPLE_EXE_LINKER_FLAGS})
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add_executable(matrix example/matrix.cpp)
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target_compile_options(matrix PRIVATE ${EXAMPLE_CXX_FLAGS})
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target_link_libraries(matrix ${EXAMPLE_EXE_LINKER_FLAGS})
@@ -86,6 +89,8 @@ add_test(builder ${PROJECT_SOURCE_DIR}/unittest/taskflow -tc=Taskflow.Builder)
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add_test(dispatch ${PROJECT_SOURCE_DIR}/unittest/taskflow -tc=Taskflow.Dispatch)
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add_test(parallel_for ${PROJECT_SOURCE_DIR}/unittest/taskflow -tc=Taskflow.ParallelFor)
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add_test(reduce ${PROJECT_SOURCE_DIR}/unittest/taskflow -tc=Taskflow.Reduce)
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add_test(reduce_min ${PROJECT_SOURCE_DIR}/unittest/taskflow -tc=Taskflow.ReduceMin)
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add_test(reduce_max ${PROJECT_SOURCE_DIR}/unittest/taskflow -tc=Taskflow.ReduceMax)
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#add_test(parallel_range ${PROJECT_SOURCE_DIR}/unittest/taskflow -tc=Taskflow.ParallelRange)
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‎example/parallel_for.cpp‎

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@@ -32,7 +32,7 @@ void taskflow(int N) {
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tf::Taskflow tf;
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tf.parallel_for(range, [&] (const int i) {
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printf("fib[%d]=%d\n", i, fib(i));
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});
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}, 1);
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tf.wait_for_all();
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auto tend = std::chrono::steady_clock::now();

‎example/reduce.cpp‎

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// This example demonstrates how to use 'reduce' method.
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#include "taskflow.hpp"
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#include <chrono>
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#include <limits.h>
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struct Data {
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int a {::rand()};
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int b {::rand()};
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int transform() const {
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return a*a + 2*a*b + b*b;
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}
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};
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// Procedure: reduce
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// This procedure demonstrates
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void reduce() {
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std::vector<int> data;
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for(int i=0; i<40000000; ++i) {
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data.push_back(::rand());
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}
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// sequential method
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std::cout << "running sequential method ..." << std::endl;
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auto sbeg = std::chrono::steady_clock::now();
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auto smin = std::numeric_limits<int>::max();
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for(auto& d : data) {
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smin = std::min(smin, d);
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}
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auto send = std::chrono::steady_clock::now();
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std::cout << "[sequential] reduce: "
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<< std::chrono::duration_cast<std::chrono::milliseconds>(send - sbeg).count()
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<< std::endl;
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// taskflow
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std::cout << "running taskflow method ..." << std::endl;
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auto tbeg = std::chrono::steady_clock::now();
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tf::Taskflow tf;
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auto tmin = std::numeric_limits<int>::max();
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tf.reduce(data.begin(), data.end(), tmin, [] (const auto& l, const auto& r) {
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return std::min(l, r);
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});
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tf.wait_for_all();
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auto tend = std::chrono::steady_clock::now();
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std::cout << "[taskflow] reduce: "
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<< std::chrono::duration_cast<std::chrono::milliseconds>(tend - tbeg).count()
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<< std::endl;
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// assertion
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assert(tmin == smin);
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}
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// Procedure: transform_reduce
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void transform_reduce() {
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std::cout << "Benchmark: transform_reduce" << std::endl;
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std::vector<Data> data(40000000);
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// sequential method
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auto sbeg = std::chrono::steady_clock::now();
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auto smin = std::numeric_limits<int>::max();
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for(auto& d : data) {
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smin = std::min(smin, d.transform());
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}
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auto send = std::chrono::steady_clock::now();
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std::cout << "[sequential] transform_reduce "
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<< std::chrono::duration_cast<std::chrono::milliseconds>(send - sbeg).count()
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<< std::endl;
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// taskflow
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auto tbeg = std::chrono::steady_clock::now();
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tf::Taskflow tf;
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auto tmin = std::numeric_limits<int>::max();
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tf.transform_reduce(data.begin(), data.end(), tmin,
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[] (float l, float r) { return std::min(l, r); },
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[] (const Data& d) { return d.transform(); }
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);
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tf.wait_for_all();
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auto tend = std::chrono::steady_clock::now();
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std::cout << "[taskflow] transform_reduce "
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<< std::chrono::duration_cast<std::chrono::milliseconds>(tend - tbeg).count()
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<< std::endl;
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// assertion
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assert(tmin == smin);
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}
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// ------------------------------------------------------------------------------------------------
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// Function: main
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int main(int argc, char* argv[]) {
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if(argc != 2) {
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std::cerr << "usage: ./reduce [reduce|transform_reduce]" << std::endl;
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std::exit(EXIT_FAILURE);
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}
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if(std::string_view method(argv[1]); method == "reduce") {
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reduce();
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}
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else if(method == "transform_reduce") {
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transform_reduce();
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}
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else {
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std::cerr << "invalid method " << method << std::endl;
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std::exit(EXIT_FAILURE);
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}
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return 0;
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}

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