Merge pull request swiftlang#80 from graydon/cperf-fixes-oct-3

Cperf fixes oct 3

Author: graydon

run_cperf

@@ -225,7 +225,7 @@ def get_stats_dir(instance, variant):
 
 
 def get_actual_config_and_flags(config, stats):
-    flags = ("-v -j 1 -num-threads 1 -stats-output-dir '%s'" % stats)
+    flags = ("-j 1 -num-threads 1 -stats-output-dir '%s'" % stats)
     # Handle pseudo-configs
     if config == 'wmo-onone':
         flags += ' -wmo -Onone '
@@ -253,7 +253,6 @@ def execute_runner(instance, workspace, configs, args):
         runner_command = [
             './runner.py',
             '--swiftc', swiftc_path,
-            '--verbose',
             '--projects', projects,
             '--build-config', config,
             '--swift-version', '3',
@@ -331,9 +330,11 @@ def analyze_results(configs, args):
         returncodes.append(
             common.execute(
                 common_args +
+                (["--select-stats-from-csv-baseline", baseline]
+                 if os.path.exists(baseline)
+                 else []) +
                 ['--output', get_table_name('head', 'counters', variant),
                  '--exclude-timers',
-                 "--select-stats-from-csv-baseline", baseline,
                  '--compare-stats-dirs', sd_old, sd_new]))
         returncodes.append(
             common.execute(