RFR: Purge unnecessary time conversion in ShenandoahPhaseTimings::record_phase_time

[Aleksey Shipilev]

This was found when building sh/jdk8u on Mac OS X: implicit double -> jint conversion makes clang
unhappy. In fact, we don't even need to do this conversion, because we can just pass the double
along, and this also saves us from accidental truncation.

The fix goes to sh/jdk and then proliferates with backports:

diff -r c4640bf7aeb3 src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.cpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.cpp     Thu Nov 01 17:16:47 2018 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.cpp     Thu Nov 01 17:19:32 2018 +0100
@@ -62,10 +62,10 @@
   ShenandoahHeap::heap()->heuristics()->record_phase_time(phase, elapsed);
 }

-void ShenandoahPhaseTimings::record_phase_time(Phase phase, jint time_us) {
+void ShenandoahPhaseTimings::record_phase_time(Phase phase, double time) {
   assert(_policy != NULL, "Not yet initialized");
   if (!_policy->is_at_shutdown()) {
-    _timing_data[phase]._secs.add((double)time_us / 1000 / 1000);
+    _timing_data[phase]._secs.add(time);
   }
 }

diff -r c4640bf7aeb3 src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.hpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.hpp     Thu Nov 01 17:16:47 2018 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.hpp     Thu Nov 01 17:19:32 2018 +0100
@@ -347,8 +347,8 @@
   void record_phase_start(Phase phase);
   // record phase end and return elapsed time in seconds for the phase
   void record_phase_end(Phase phase);
-  // record an elapsed time in microseconds for the phase
-  void record_phase_time(Phase phase, jint time_us);
+  // record an elapsed time for the phase
+  void record_phase_time(Phase phase, double time);

   void record_workers_start(Phase phase);
   void record_workers_end(Phase phase);
diff -r c4640bf7aeb3 src/hotspot/share/gc/shenandoah/shenandoahTimingTracker.cpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahTimingTracker.cpp     Thu Nov 01 17:16:47 2018 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahTimingTracker.cpp     Thu Nov 01 17:19:32 2018 +0100
@@ -87,6 +87,6 @@
   ShenandoahPhaseTimings* phase_times = ShenandoahHeap::heap()->phase_timings();

   double t = phase_times->termination_times()->average();
-  phase_times->record_phase_time(_phase, t * 1000 * 1000);
+  phase_times->record_phase_time(_phase, t);
   debug_only(_current_termination_phase = ShenandoahPhaseTimings::_num_phases;)
 }


Testing: sh/jdk tier3_gc_shenandoah, sh/jdk8u Mac OS X builds

Thanks,
-Aleksey