#include #include "benchmark/benchmark.h" namespace { #if defined(__GNUC__) std::int64_t double_up(const std::int64_t x) __attribute__((const)); #endif std::int64_t double_up(const std::int64_t x) { return x * 2; } } // namespace // 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 buffer1[1] = ""; benchmark::DoNotOptimize(buffer1); char buffer2[2] = ""; benchmark::DoNotOptimize(buffer2); char buffer3[3] = ""; benchmark::DoNotOptimize(buffer3); char buffer8[8] = ""; benchmark::DoNotOptimize(buffer8); char buffer20[20] = ""; benchmark::DoNotOptimize(buffer20); char buffer1024[1024] = ""; benchmark::DoNotOptimize(buffer1024); char* bptr = &buffer1024[0]; benchmark::DoNotOptimize(bptr); int x = 123; benchmark::DoNotOptimize(x); int* xp = &x; benchmark::DoNotOptimize(xp); benchmark::DoNotOptimize(x += 42); std::int64_t y = double_up(x); benchmark::DoNotOptimize(y); // These tests are to e BitRef lval = BitRef::Make(); benchmark::DoNotOptimize(lval); #ifdef BENCHMARK_HAS_CXX11 // Check that accept rvalue. benchmark::DoNotOptimize(BitRef::Make()); #endif }