From d32595216cc5a39787e4f074bd1039036617d54b Mon Sep 17 00:00:00 2001
From: Kimberly Swanson <khswanson24@gmail.com>
Date: Wed, 22 May 2019 21:21:19 +0100
Subject: [PATCH] include Google Benchmark submodule, and add a benchmark

---
 .gitmodules                     |  3 +++
 CMakeLists.txt                  |  7 +++++++
 bench/CMakeLists.txt            | 18 ++++++++++++++++++
 bench/addition_bench.cpp        | 19 +++++++++++++++++++
 bench/benchmark                 |  1 +
 bench/include/bench_helpers.hpp | 10 ++++++++++
 6 files changed, 58 insertions(+)
 create mode 100644 bench/CMakeLists.txt
 create mode 100644 bench/addition_bench.cpp
 create mode 160000 bench/benchmark
 create mode 100644 bench/include/bench_helpers.hpp

diff --git a/.gitmodules b/.gitmodules
index 60d7d88..6a78cf3 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "cmake-modules"]
 	path = cmake-modules
 	url = https://github.com/bilke/cmake-modules.git
+[submodule "bench/benchmark"]
+	path = bench/benchmark
+	url = https://github.com/google/benchmark.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1424708..5415334 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -44,3 +44,10 @@ set_target_properties(Boost.Real_headers PROPERTIES
                                                  EXCLUDE_FROM_ALL TRUE
                                                  EXCLUDE_FROM_DEFAULT_BUILD TRUE
                                                  LINKER_LANGUAGE CXX)
+                                             
+#Google Benchmark, turn on/off with -DBENCH=ON or OFF
+find_package(Threads REQUIRED)
+option(BENCH "Build benchmarks" ON)
+if(BENCH)
+    add_subdirectory(bench)
+endif()
diff --git a/bench/CMakeLists.txt b/bench/CMakeLists.txt
new file mode 100644
index 0000000..65015d2
--- /dev/null
+++ b/bench/CMakeLists.txt
@@ -0,0 +1,18 @@
+set(BENCHMARK_ENABLE_TESTING OFF CACHE BOOL "Suppressing benchmark's tests" FORCE)
+
+add_subdirectory(benchmark)
+include_directories(benchmark/include
+    include)
+
+set(bench_list
+    addition_bench.cpp
+    )
+
+add_executable(main_bench ${bench_list})
+
+
+target_link_libraries(main_bench
+    benchmark
+    Boost.Real
+    ${CMAKE_THREAD_LIBS_INIT}
+    )
diff --git a/bench/addition_bench.cpp b/bench/addition_bench.cpp
new file mode 100644
index 0000000..6cd1fa6
--- /dev/null
+++ b/bench/addition_bench.cpp
@@ -0,0 +1,19 @@
+#include <bench_helpers.hpp>
+#include <benchmark/benchmark.h>
+#include <real/real.hpp>
+#include <iostream>
+
+// this process uses an absurd amount of memory
+// sums 10,000 reals, then evaluates.
+static void BM_RealAddition10000(benchmark::State& state) {
+    boost::real::real a ("1.2");
+    boost::real::real c ("0");
+
+    for (auto i : state)
+        for (int i = 0; i < 10000; i++)
+            c += a;
+    std::cout << c << '\n';
+}
+BENCHMARK(BM_RealAddition10000);
+
+BENCHMARK_MAIN();
diff --git a/bench/benchmark b/bench/benchmark
new file mode 160000
index 0000000..090faec
--- /dev/null
+++ b/bench/benchmark
@@ -0,0 +1 @@
+Subproject commit 090faecb454fbd6e6e17a75ef8146acb037118d4
diff --git a/bench/include/bench_helpers.hpp b/bench/include/bench_helpers.hpp
new file mode 100644
index 0000000..2043a3d
--- /dev/null
+++ b/bench/include/bench_helpers.hpp
@@ -0,0 +1,10 @@
+#ifndef BOOST_REAL_BENCH_HELPERS_HPP
+#define BOOST_REAL_BENCH_HELPERS_HPP
+
+
+#include <real/real.hpp>
+
+unsigned int boost::real::real::maximum_precision = 10;
+unsigned int boost::real::real_algorithm::maximum_precision = 10;
+
+#endif //BOOST_REAL_BENCH_HELPERS_HPP