diff options
Diffstat (limited to 'src/bench/nanobench.h')
| -rw-r--r-- | src/bench/nanobench.h | 43 |
1 files changed, 24 insertions, 19 deletions
diff --git a/src/bench/nanobench.h b/src/bench/nanobench.h index 030d6ebf6a..27df08fb69 100644 --- a/src/bench/nanobench.h +++ b/src/bench/nanobench.h @@ -33,7 +33,7 @@ // see https://semver.org/ #define ANKERL_NANOBENCH_VERSION_MAJOR 4 // incompatible API changes #define ANKERL_NANOBENCH_VERSION_MINOR 3 // backwards-compatible changes -#define ANKERL_NANOBENCH_VERSION_PATCH 4 // backwards-compatible bug fixes +#define ANKERL_NANOBENCH_VERSION_PATCH 6 // backwards-compatible bug fixes /////////////////////////////////////////////////////////////////////////////////////////////////// // public facing api - as minimal as possible @@ -88,13 +88,15 @@ } while (0) #endif -#if defined(__linux__) && defined(PERF_EVENT_IOC_ID) && defined(PERF_COUNT_HW_REF_CPU_CYCLES) && defined(PERF_FLAG_FD_CLOEXEC) && \ - !defined(ANKERL_NANOBENCH_DISABLE_PERF_COUNTERS) -// only enable perf counters on kernel 3.14 which seems to have all the necessary defines. The three PERF_... defines are not in -// kernel 2.6.32 (all others are). -# define ANKERL_NANOBENCH_PRIVATE_PERF_COUNTERS() 1 -#else -# define ANKERL_NANOBENCH_PRIVATE_PERF_COUNTERS() 0 +#define ANKERL_NANOBENCH_PRIVATE_PERF_COUNTERS() 0 +#if defined(__linux__) && !defined(ANKERL_NANOBENCH_DISABLE_PERF_COUNTERS) +# include <linux/version.h> +# if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 14, 0) +// PERF_COUNT_HW_REF_CPU_CYCLES only available since kernel 3.3 +// PERF_FLAG_FD_CLOEXEC since kernel 3.14 +# undef ANKERL_NANOBENCH_PRIVATE_PERF_COUNTERS +# define ANKERL_NANOBENCH_PRIVATE_PERF_COUNTERS() 1 +# endif #endif #if defined(__clang__) @@ -2210,20 +2212,20 @@ struct IterationLogic::Impl { columns.emplace_back(10, 1, "err%", "%", rErrorMedian * 100.0); double rInsMedian = -1.0; - if (mResult.has(Result::Measure::instructions)) { + if (mBench.performanceCounters() && mResult.has(Result::Measure::instructions)) { rInsMedian = mResult.median(Result::Measure::instructions); columns.emplace_back(18, 2, "ins/" + mBench.unit(), "", rInsMedian / mBench.batch()); } double rCycMedian = -1.0; - if (mResult.has(Result::Measure::cpucycles)) { + if (mBench.performanceCounters() && mResult.has(Result::Measure::cpucycles)) { rCycMedian = mResult.median(Result::Measure::cpucycles); columns.emplace_back(18, 2, "cyc/" + mBench.unit(), "", rCycMedian / mBench.batch()); } if (rInsMedian > 0.0 && rCycMedian > 0.0) { columns.emplace_back(9, 3, "IPC", "", rCycMedian <= 0.0 ? 0.0 : rInsMedian / rCycMedian); } - if (mResult.has(Result::Measure::branchinstructions)) { + if (mBench.performanceCounters() && mResult.has(Result::Measure::branchinstructions)) { double rBraMedian = mResult.median(Result::Measure::branchinstructions); columns.emplace_back(17, 2, "bra/" + mBench.unit(), "", rBraMedian / mBench.batch()); if (mResult.has(Result::Measure::branchmisses)) { @@ -2402,6 +2404,14 @@ public: return (a + divisor / 2) / divisor; } + ANKERL_NANOBENCH_NO_SANITIZE("integer", "undefined") + static inline uint32_t mix(uint32_t x) noexcept { + x ^= x << 13; + x ^= x >> 17; + x ^= x << 5; + return x; + } + template <typename Op> ANKERL_NANOBENCH_NO_SANITIZE("integer", "undefined") void calibrate(Op&& op) { @@ -2441,15 +2451,10 @@ public: uint64_t const numIters = 100000U + (std::random_device{}() & 3); uint64_t n = numIters; uint32_t x = 1234567; - auto fn = [&]() { - x ^= x << 13; - x ^= x >> 17; - x ^= x << 5; - }; beginMeasure(); while (n-- > 0) { - fn(); + x = mix(x); } endMeasure(); detail::doNotOptimizeAway(x); @@ -2459,8 +2464,8 @@ public: beginMeasure(); while (n-- > 0) { // we now run *twice* so we can easily calculate the overhead - fn(); - fn(); + x = mix(x); + x = mix(x); } endMeasure(); detail::doNotOptimizeAway(x); |