Tenure allocation sites only when semi-space is maximum size.

src/heap.h

 // 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.
 
 #ifndef V8_HEAP_H_
 #define V8_HEAP_H_
 
 #include <cmath>
 
 #include "allocation.h"
@@ skipping 1341 matching lines @@
   }
 
   bool flush_monomorphic_ics() { return flush_monomorphic_ics_; }
 
   int64_t amount_of_external_allocated_memory() {
     return amount_of_external_allocated_memory_;
   }
 
   void DeoptMarkedAllocationSites();
 
+  bool MaximumSizeScavenge() {
+    return maximum_size_scavenges_ > 0;
+  }
+
   // ObjectStats are kept in two arrays, counts and sizes. Related stats are
   // stored in a contiguous linear buffer. Stats groups are stored one after
   // another.
   enum {
     FIRST_CODE_KIND_SUB_TYPE = LAST_TYPE + 1,
     FIRST_FIXED_ARRAY_SUB_TYPE =
         FIRST_CODE_KIND_SUB_TYPE + Code::NUMBER_OF_KINDS,
     FIRST_CODE_AGE_SUB_TYPE =
         FIRST_FIXED_ARRAY_SUB_TYPE + LAST_FIXED_ARRAY_SUB_TYPE + 1,
     OBJECT_STATS_COUNT = FIRST_CODE_AGE_SUB_TYPE + Code::kCodeAgeCount + 1
@@ skipping 640 matching lines @@
   static const int kYoungSurvivalRateAllowedDeviation = 15;
 
   static const int kOldSurvivalRateLowThreshold = 10;
 
   int high_survival_rate_period_length_;
   intptr_t promoted_objects_size_;
   double promotion_rate_;
   intptr_t semi_space_copied_object_size_;
   double semi_space_copied_rate_;
 
+  // This is the pretenuring trigger for allocation sites that are in maybe
+  // tenure state. When we switched to the maximum new space size we deoptimize
+  // the code that belongs to the allocation site and derive the lifetime
+  // of the allocation site.
+  unsigned int maximum_size_scavenges_;
+
   // TODO(hpayer): Allocation site pretenuring may make this method obsolete.
   // Re-visit incremental marking heuristics.
   bool IsHighSurvivalRate() {
     return high_survival_rate_period_length_ > 0;
   }
 
   void SelectScavengingVisitorsTable();
 
   void StartIdleRound() {
     mark_sweeps_since_idle_round_started_ = 0;
@@ skipping 729 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_