bench: Add support for measuring CPU cycles

This adds cycle min/max/avg to the statistics.

Supported on x86 and x86_64 (natively through rdtsc), as well as Linux
(perf syscall).

1 files changed, 8 insertions, 2 deletions

diff --git a/src/bench/bench.h b/src/bench/bench.h
index f13b145aa..caf73e949 100644
--- a/src/bench/bench.h
+++ b/src/bench/bench.h
@@ -41,12 +41,18 @@ namespace benchmark {
         double maxElapsed;
         double beginTime;
         double lastTime, minTime, maxTime, countMaskInv;
-        int64_t count;
-        int64_t countMask;
+        uint64_t count;
+        uint64_t countMask;
+        uint64_t beginCycles;
+        uint64_t lastCycles;
+        uint64_t minCycles;
+        uint64_t maxCycles;
     public:
         State(std::string _name, double _maxElapsed) : name(_name), maxElapsed(_maxElapsed), count(0) {
             minTime = std::numeric_limits<double>::max();
             maxTime = std::numeric_limits<double>::min();
+            minCycles = std::numeric_limits<uint64_t>::max();
+            maxCycles = std::numeric_limits<uint64_t>::min();
             countMask = 1;
             countMaskInv = 1./(countMask + 1);
         }