From 620bae34cfe10e20daa0dcec7e4b9ffee8dfd397 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Thu, 9 Nov 2017 11:48:13 -0500
Subject: Require a steady clock for bench with at least micro precision

---
 src/bench/bench.cpp | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'src/bench/bench.cpp')

diff --git a/src/bench/bench.cpp b/src/bench/bench.cpp
index dd4ba5ab0..4c5a03677 100644
--- a/src/bench/bench.cpp
+++ b/src/bench/bench.cpp
@@ -23,6 +23,9 @@ void
 benchmark::BenchRunner::RunAll(benchmark::duration elapsedTimeForOne)
 {
     perf_init();
+    if (std::ratio_less_equal<benchmark::clock::period, std::micro>::value) {
+        std::cerr << "WARNING: Clock precision is worse than microsecond - benchmarks may be less accurate!\n";
+    }
     std::cout << "#Benchmark" << "," << "count" << "," << "min(ns)" << "," << "max(ns)" << "," << "average(ns)" << ","
               << "min_cycles" << "," << "max_cycles" << "," << "average_cycles" << "\n";
 
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