Represent speed in GCTracer functions as double instead of int.

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 1336 matching lines @@
             collector, gc_callback_flags);
   }
   gc_post_processing_depth_--;
 
   isolate_->eternal_handles()->PostGarbageCollectionProcessing(this);
 
   // Update relocatables.
   Relocatable::PostGarbageCollectionProcessing(isolate_);
 
   double gc_speed = tracer()->CombinedMarkCompactSpeedInBytesPerMillisecond();
-  double mutator_speed = static_cast<double>(
-      tracer()
-          ->CurrentOldGenerationAllocationThroughputInBytesPerMillisecond());
+  double mutator_speed =
+      tracer()->CurrentOldGenerationAllocationThroughputInBytesPerMillisecond();
   intptr_t old_gen_size = PromotedSpaceSizeOfObjects();
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
         amount_of_external_allocated_memory_;
     SetOldGenerationAllocationLimit(old_gen_size, gc_speed, mutator_speed);
   } else if (HasLowYoungGenerationAllocationRate() &&
              old_generation_size_configured_) {
     DampenOldGenerationAllocationLimit(old_gen_size, gc_speed, mutator_speed);
   }
@@ skipping 2758 matching lines @@
   // mutator_utilization = (1 / mutator_speed) /
   //                       (1 / mutator_speed + 1 / gc_speed)
   // mutator_utilization = gc_speed / (mutator_speed + gc_speed)
   return gc_speed / (mutator_speed + gc_speed);
 }
 
 
 double Heap::YoungGenerationMutatorUtilization() {
   double mutator_speed = static_cast<double>(
       tracer()->NewSpaceAllocationThroughputInBytesPerMillisecond());
-  double gc_speed = static_cast<double>(
-      tracer()->ScavengeSpeedInBytesPerMillisecond(kForSurvivedObjects));
+  double gc_speed =
+      tracer()->ScavengeSpeedInBytesPerMillisecond(kForSurvivedObjects);
   double result = ComputeMutatorUtilization(mutator_speed, gc_speed);
   if (FLAG_trace_mutator_utilization) {
     PrintIsolate(isolate(),
                  "Young generation mutator utilization = %.3f ("
                  "mutator_speed=%.f, gc_speed=%.f)\n",
                  result, mutator_speed, gc_speed);
   }
   return result;
 }
 
@@ skipping 58 matching lines @@
     event.time_ms = MonotonicallyIncreasingTimeInMs();
     memory_reducer_->NotifyPossibleGarbage(event);
   }
   optimize_for_memory_usage_ = true;
 }
 
 void Heap::ReduceNewSpaceSize() {
   // TODO(ulan): Unify this constant with the similar constant in
   // GCIdleTimeHandler once the change is merged to 4.5.
   static const size_t kLowAllocationThroughput = 1000;
-  const size_t allocation_throughput =
+  const double allocation_throughput =
       tracer()->CurrentAllocationThroughputInBytesPerMillisecond();
 
   if (FLAG_predictable) return;
 
   if (ShouldReduceMemory() ||
       ((allocation_throughput != 0) &&
        (allocation_throughput < kLowAllocationThroughput))) {
     new_space_.Shrink();
     UncommitFromSpace();
   }
 }
 
 
 void Heap::FinalizeIncrementalMarkingIfComplete(const char* comment) {
   if (incremental_marking()->IsMarking() &&
       (incremental_marking()->IsReadyToOverApproximateWeakClosure() ||
        (!incremental_marking()->finalize_marking_completed() &&
         mark_compact_collector()->marking_deque()->IsEmpty()))) {
     FinalizeIncrementalMarking(comment);
   } else if (incremental_marking()->IsComplete() ||
              (mark_compact_collector()->marking_deque()->IsEmpty())) {
     CollectAllGarbage(current_gc_flags_, comment);
   }
 }
 
 
 bool Heap::TryFinalizeIdleIncrementalMarking(double idle_time_in_ms) {
   size_t size_of_objects = static_cast<size_t>(SizeOfObjects());
-  size_t final_incremental_mark_compact_speed_in_bytes_per_ms =
-      static_cast<size_t>(
-          tracer()->FinalIncrementalMarkCompactSpeedInBytesPerMillisecond());
+  double final_incremental_mark_compact_speed_in_bytes_per_ms =
+      tracer()->FinalIncrementalMarkCompactSpeedInBytesPerMillisecond();
   if (incremental_marking()->IsReadyToOverApproximateWeakClosure() ||
       (!incremental_marking()->finalize_marking_completed() &&
        mark_compact_collector()->marking_deque()->IsEmpty() &&
        gc_idle_time_handler_->ShouldDoOverApproximateWeakClosure(
-           static_cast<size_t>(idle_time_in_ms)))) {
+           idle_time_in_ms))) {
     FinalizeIncrementalMarking(
         "Idle notification: finalize incremental marking");
     return true;
   } else if (incremental_marking()->IsComplete() ||
              (mark_compact_collector()->marking_deque()->IsEmpty() &&
               gc_idle_time_handler_->ShouldDoFinalIncrementalMarkCompact(
-                  static_cast<size_t>(idle_time_in_ms), size_of_objects,
+                  idle_time_in_ms, size_of_objects,
                   final_incremental_mark_compact_speed_in_bytes_per_ms))) {
     CollectAllGarbage(current_gc_flags_,
                       "idle notification: finalize incremental marking");
     return true;
   }
   return false;
 }
 
 void Heap::RegisterReservationsForBlackAllocation(Reservation* reservations) {
   // TODO(hpayer): We do not have to iterate reservations on black objects
@@ skipping 2201 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8