report the compiler in the benchmark and increase the default number of iterations

Author: imakris

CMakeLists.txt

@@ -11,11 +11,57 @@ find_package(OpenMP REQUIRED)
 target_link_libraries(benchmark PRIVATE OpenMP::OpenMP_CXX)
 
 if (MSVC)
-    target_compile_options(benchmark PRIVATE /W4 /permissive- /bigobj)
+    set(MEXCE_BENCHMARK_LOCAL_FLAGS /W4 /permissive- /bigobj)
 else()
-    target_compile_options(benchmark PRIVATE -Wall -Wextra -Wpedantic)
+    set(MEXCE_BENCHMARK_LOCAL_FLAGS -Wall -Wextra -Wpedantic)
 endif()
 
+target_compile_options(benchmark PRIVATE ${MEXCE_BENCHMARK_LOCAL_FLAGS})
+
+set(MEXCE_BENCHMARK_COMPILER "${CMAKE_CXX_COMPILER_ID}")
+if (CMAKE_CXX_COMPILER_VERSION)
+    string(APPEND MEXCE_BENCHMARK_COMPILER " ${CMAKE_CXX_COMPILER_VERSION}")
+endif()
+
+set(MEXCE_BENCHMARK_FLAGS "${CMAKE_CXX_FLAGS}")
+if (CMAKE_BUILD_TYPE)
+    string(TOUPPER "${CMAKE_BUILD_TYPE}" MEXCE_BUILD_TYPE_UPPER)
+    if (DEFINED CMAKE_CXX_FLAGS_${MEXCE_BUILD_TYPE_UPPER})
+        set(MEXCE_BUILD_TYPE_FLAGS "${CMAKE_CXX_FLAGS_${MEXCE_BUILD_TYPE_UPPER}}")
+        if (MEXCE_BUILD_TYPE_FLAGS)
+            if (MEXCE_BENCHMARK_FLAGS)
+                string(APPEND MEXCE_BENCHMARK_FLAGS " ")
+            endif()
+            string(APPEND MEXCE_BENCHMARK_FLAGS "${MEXCE_BUILD_TYPE_FLAGS}")
+        endif()
+    endif()
+endif()
+
+if (MEXCE_BENCHMARK_LOCAL_FLAGS)
+    list(JOIN MEXCE_BENCHMARK_LOCAL_FLAGS " " MEXCE_BENCHMARK_LOCAL_FLAGS_STR)
+    if (MEXCE_BENCHMARK_LOCAL_FLAGS_STR)
+        if (MEXCE_BENCHMARK_FLAGS)
+            string(APPEND MEXCE_BENCHMARK_FLAGS " ")
+        endif()
+        string(APPEND MEXCE_BENCHMARK_FLAGS "${MEXCE_BENCHMARK_LOCAL_FLAGS_STR}")
+    endif()
+endif()
+
+string(STRIP "${MEXCE_BENCHMARK_FLAGS}" MEXCE_BENCHMARK_FLAGS)
+if ("${MEXCE_BENCHMARK_FLAGS}" STREQUAL "")
+    set(MEXCE_BENCHMARK_FLAGS "<none>")
+endif()
+
+foreach(_var MEXCE_BENCHMARK_COMPILER MEXCE_BENCHMARK_FLAGS)
+    string(REPLACE "\\" "\\\\" ${_var} "${${_var}}")
+    string(REPLACE "\"" "\\\"" ${_var} "${${_var}}")
+endforeach()
+
+target_compile_definitions(benchmark PRIVATE
+    BENCHMARK_COMPILER="${MEXCE_BENCHMARK_COMPILER}"
+    BENCHMARK_COMPILER_FLAGS="${MEXCE_BENCHMARK_FLAGS}"
+)
+
 enable_testing()
 add_test(NAME benchmark_quick
          COMMAND benchmark 5 ${CMAKE_BINARY_DIR}/benchmark_quick_results.txt)

test/benchmark.cpp

@@ -189,7 +189,7 @@ int main(int argc, char* argv[])
         return 1;
     }
 
-    int iterations = 10000;
+    int iterations = 100000;
     std::string output_path = "benchmark_results.txt";
     bool iterations_set = false;
 
@@ -263,6 +263,13 @@ int main(int argc, char* argv[])
     }
     std::ostream& out = *output_stream;
 
+#ifdef BENCHMARK_COMPILER
+    out << "Compiler: " << BENCHMARK_COMPILER << std::endl;
+#endif
+#ifdef BENCHMARK_COMPILER_FLAGS
+    out << "Compiler flags: " << BENCHMARK_COMPILER_FLAGS << std::endl;
+#endif
+
     const volatile std::size_t total_expressions = mexce::benchmark_data::kExpressionCount; // volatile, only for MSVC to shut up
     if (total_expressions == 0) {
         out << "No expressions available for benchmarking." << std::endl;
@@ -491,8 +498,7 @@ int main(int argc, char* argv[])
     };
 
     std::vector<std::string> row_labels;
-    row_labels.reserve(k_num_bins + 3);
-    row_labels.emplace_back("Samples");
+    row_labels.reserve(k_num_bins + 2);
     row_labels.emplace_back("0 (exact)");
     for (size_t bin_idx = 0; bin_idx < k_num_bins; ++bin_idx) {
         char buf[32];
@@ -516,7 +522,6 @@ int main(int argc, char* argv[])
         const Distribution_column& column = distribution_columns[column_idx];
         std::vector<std::string>& values = column_values[column_idx];
         values.reserve(row_labels.size());
-        values.emplace_back(std::to_string(column.comparisons));
         if (column.comparisons == 0) {
             values.emplace_back("-");
             for (size_t bin_idx = 0; bin_idx < k_num_bins + 1; ++bin_idx) {