Fixes #1663 by increasing the kMaxIterations limit.

include/benchmark/benchmark.h

@@ -1895,7 +1895,10 @@ class BENCHMARK_EXPORT ConsoleReporter : public BenchmarkReporter {
     OO_Defaults = OO_ColorTabular
   };
   explicit ConsoleReporter(OutputOptions opts_ = OO_Defaults)
-      : output_options_(opts_), name_field_width_(0), printed_header_(false) {}
+      : output_options_(opts_),
+        name_field_width_(0),
+        iterations_field_width_(0),
+        printed_header_(false) {}
 
   bool ReportContext(const Context& context) BENCHMARK_OVERRIDE;
   void ReportRuns(const std::vector<Run>& reports) BENCHMARK_OVERRIDE;
@@ -1907,6 +1910,7 @@ class BENCHMARK_EXPORT ConsoleReporter : public BenchmarkReporter {
   OutputOptions output_options_;
   size_t name_field_width_;
   UserCounters prev_counters_;
+  size_t iterations_field_width_;
   bool printed_header_;
 };
 

src/benchmark_runner.cc

@@ -64,7 +64,7 @@ MemoryManager* memory_manager = nullptr;
 
 namespace {
 
-static constexpr IterationCount kMaxIterations = 1000000000;
+static constexpr IterationCount kMaxIterations = 1000000000000;
 const double kDefaultMinTime =
     std::strtod(::benchmark::kDefaultMinTimeStr, /*p_end*/ nullptr);
 

src/console_reporter.cc

@@ -38,6 +38,7 @@ bool ConsoleReporter::ReportContext(const Context& context) {
   name_field_width_ = context.name_field_width;
   printed_header_ = false;
   prev_counters_.clear();
+  iterations_field_width_ = std::string("Iterations").length();
 
   PrintBasicContext(&GetErrorStream(), context);
 
@@ -56,8 +57,9 @@ bool ConsoleReporter::ReportContext(const Context& context) {
 BENCHMARK_EXPORT
 void ConsoleReporter::PrintHeader(const Run& run) {
   std::string str =
-      FormatString("%-*s %13s %15s %12s", static_cast<int>(name_field_width_),
-                   "Benchmark", "Time", "CPU", "Iterations");
+      FormatString("%-*s %13s %15s %*s", static_cast<int>(name_field_width_),
+                   "Benchmark", "Time", "CPU",
+                   static_cast<int>(iterations_field_width_) + 2, "Iterations");
   if (!run.counters.empty()) {
     if (output_options_ & OO_Tabular) {
       for (auto const& c : run.counters) {
@@ -73,6 +75,14 @@ void ConsoleReporter::PrintHeader(const Run& run) {
 
 BENCHMARK_EXPORT
 void ConsoleReporter::ReportRuns(const std::vector<Run>& reports) {
+  auto max_iterations = std::max_element(reports.begin(), reports.end(),
+                                         [](const Run& a, const Run& b) {
+                                           return a.iterations > b.iterations;
+                                         })
+                            ->iterations;
+  auto cur_iterations_field_width = std::max(
+      std::to_string(max_iterations).length(), iterations_field_width_);
+
   for (const auto& run : reports) {
     // print the header:
     // --- if none was printed yet
@@ -81,9 +91,12 @@ void ConsoleReporter::ReportRuns(const std::vector<Run>& reports) {
     //     has different fields from the prev header
     print_header |= (output_options_ & OO_Tabular) &&
                     (!internal::SameNames(run.counters, prev_counters_));
+    // --- or if the width of the iterations field has increased
+    print_header |= (cur_iterations_field_width > iterations_field_width_);
     if (print_header) {
       printed_header_ = true;
       prev_counters_ = run.counters;
+      iterations_field_width_ = cur_iterations_field_width;
       PrintHeader(run);
     }
     // As an alternative to printing the headers like this, we could sort
@@ -171,7 +184,8 @@ void ConsoleReporter::PrintRunData(const Run& result) {
   }
 
   if (!result.report_big_o && !result.report_rms) {
-    printer(Out, COLOR_CYAN, "%10lld", result.iterations);
+    printer(Out, COLOR_CYAN, "%*lld", static_cast<int>(iterations_field_width_),
+            result.iterations);
   }
 
   for (auto& c : result.counters) {

test/user_counters_tabular_test.cc

@@ -63,6 +63,9 @@ ADD_CASES(TC_CSVOut, {{"%csv_header,"
 
 void BM_Counters_Tabular(benchmark::State& state) {
   for (auto _ : state) {
+    // This test requires a non-zero CPU time to avoid divide-by-zero
+    auto iterations = state.iterations();
+    benchmark::DoNotOptimize(iterations);
   }
   namespace bm = benchmark;
   state.counters.insert({
@@ -430,6 +433,9 @@ CHECK_BENCHMARK_RESULTS("BM_CounterRates_Tabular/threads:%int",
 // set only some of the counters
 void BM_CounterSet0_Tabular(benchmark::State& state) {
   for (auto _ : state) {
+    // This test requires a non-zero CPU time to avoid divide-by-zero
+    auto iterations = state.iterations();
+    benchmark::DoNotOptimize(iterations);
   }
   namespace bm = benchmark;
   state.counters.insert({
@@ -470,6 +476,9 @@ CHECK_BENCHMARK_RESULTS("BM_CounterSet0_Tabular", &CheckSet0);
 // again.
 void BM_CounterSet1_Tabular(benchmark::State& state) {
   for (auto _ : state) {
+    // This test requires a non-zero CPU time to avoid divide-by-zero
+    auto iterations = state.iterations();
+    benchmark::DoNotOptimize(iterations);
   }
   namespace bm = benchmark;
   state.counters.insert({
@@ -514,6 +523,9 @@ CHECK_BENCHMARK_RESULTS("BM_CounterSet1_Tabular/threads:%int", &CheckSet1);
 // set only some of the counters, different set now.
 void BM_CounterSet2_Tabular(benchmark::State& state) {
   for (auto _ : state) {
+    // This test requires a non-zero CPU time to avoid divide-by-zero
+    auto iterations = state.iterations();
+    benchmark::DoNotOptimize(iterations);
   }
   namespace bm = benchmark;
   state.counters.insert({