simplify nanobench --quiet / -q output

bench/nanobench.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <ctype.h>
 
 #include "nanobench.h"
@@ skipping 1113 matching lines @@
     }
 
     const double overhead = estimate_timer_overhead();
     SkDebugf("Timer overhead: %s\n", HUMANIZE(overhead));
 
     SkTArray<double> samples;
 
     if (kAutoTuneLoops != FLAGS_loops) {
         SkDebugf("Fixed number of loops; times would only be misleading so we won't print them.\n");
     } else if (FLAGS_quiet) {
-        SkDebugf("median\tbench\tconfig\n");
+        SkDebugf("! -> high variance, ? -> moderate variance\n");
+        SkDebugf("    micros   \tbench\n");
     } else if (FLAGS_ms) {
         SkDebugf("curr/maxrss\tloops\tmin\tmedian\tmean\tmax\tstddev\tsamples\tconfig\tbench\n");
     } else {
         SkDebugf("curr/maxrss\tloops\tmin\tmedian\tmean\tmax\tstddev\t%-*s\tconfig\tbench\n",
                  FLAGS_samples, "samples");
     }
 
     SkTDArray<Config> configs;
     create_configs(&configs);
 
@@ skipping 89 matching lines @@
             if (kAutoTuneLoops != FLAGS_loops) {
                 if (configs.count() == 1) {
                     config = ""; // Only print the config if we run the same bench on more than one.
                 }
                 SkDebugf("%4d/%-4dMB\t%s\t%s\n"
                          , sk_tools::getCurrResidentSetSizeMB()
                          , sk_tools::getMaxResidentSetSizeMB()
                          , bench->getUniqueName()
                          , config);
             } else if (FLAGS_quiet) {
-                if (configs.count() == 1) {
-                    config = ""; // Only print the config if we run the same bench on more than one.
-                }
-                SkDebugf("%s\t%s\t%s\n", HUMANIZE(stats.median), bench->getUniqueName(), config);
+                const char* mark = " ";
+                const double stddev_percent = 100 * sqrt(stats.var) / stats.mean;
+                if (stddev_percent >  5) mark = "?";
+                if (stddev_percent > 10) mark = "!";
+
+                SkDebugf("%10.2f %s\t%s\t%s\n",
+                         stats.median*1e3, mark, bench->getUniqueName(), config);
             } else {
                 const double stddev_percent = 100 * sqrt(stats.var) / stats.mean;
                 SkDebugf("%4d/%-4dMB\t%d\t%s\t%s\t%s\t%s\t%.0f%%\t%s\t%s\t%s\n"
                         , sk_tools::getCurrResidentSetSizeMB()
                         , sk_tools::getMaxResidentSetSizeMB()
                         , loops
                         , HUMANIZE(stats.min)
                         , HUMANIZE(stats.median)
                         , HUMANIZE(stats.mean)
                         , HUMANIZE(stats.max)
@@ skipping 34 matching lines @@
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return nanobench_main();
 }
 #endif