--- /dev/null
+#include "benchmark/benchmark.h"
+
+#include <cstdint>
+
+namespace {
+#if defined(__GNUC__)
+std::uint64_t double_up(const std::uint64_t x) __attribute__((const));
+#endif
+std::uint64_t double_up(const std::uint64_t x) { return x * 2; }
+}
+
+// Using DoNotOptimize on types like BitRef seem to cause a lot of problems
+// with the inline assembly on both GCC and Clang.
+struct BitRef {
+ int index;
+ unsigned char &byte;
+
+public:
+ static BitRef Make() {
+ static unsigned char arr[2] = {};
+ BitRef b(1, arr[0]);
+ return b;
+ }
+private:
+ BitRef(int i, unsigned char& b) : index(i), byte(b) {}
+};
+
+int main(int, char*[]) {
+ // this test verifies compilation of DoNotOptimize() for some types
+
+ char buffer8[8] = "";
+ benchmark::DoNotOptimize(buffer8);
+
+ char buffer20[20] = "";
+ benchmark::DoNotOptimize(buffer20);
+
+ char buffer1024[1024] = "";
+ benchmark::DoNotOptimize(buffer1024);
+ benchmark::DoNotOptimize(&buffer1024[0]);
+
+ int x = 123;
+ benchmark::DoNotOptimize(x);
+ benchmark::DoNotOptimize(&x);
+ benchmark::DoNotOptimize(x += 42);
+
+ benchmark::DoNotOptimize(double_up(x));
+
+ // These tests are to e
+ benchmark::DoNotOptimize(BitRef::Make());
+ BitRef lval = BitRef::Make();
+ benchmark::DoNotOptimize(lval);
+}