Reland of [heap] Simplify distribution of remaining memory during sweeping & compaction

src/heap/mark-compact.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/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 3263 matching lines @@
   // Used for trace summary.
   intptr_t compaction_speed = 0;
   if (FLAG_trace_fragmentation) {
     compaction_speed = heap()->tracer()->CompactionSpeedInBytesPerMillisecond();
   }
 
   const int num_tasks = NumberOfParallelCompactionTasks(num_pages, live_bytes);
 
   // Set up compaction spaces.
   Evacuator** evacuators = new Evacuator*[num_tasks];
-  CompactionSpaceCollection** compaction_spaces_for_tasks =
-      new CompactionSpaceCollection*[num_tasks];
   for (int i = 0; i < num_tasks; i++) {
     evacuators[i] = new Evacuator(this, evacuation_candidates_,
                                   newspace_evacuation_candidates_);
-    compaction_spaces_for_tasks[i] = evacuators[i]->compaction_spaces();
   }
-  heap()->old_space()->DivideUponCompactionSpaces(compaction_spaces_for_tasks,
-                                                  num_tasks);
-  heap()->code_space()->DivideUponCompactionSpaces(compaction_spaces_for_tasks,
-                                                   num_tasks);
-  delete[] compaction_spaces_for_tasks;
 
   // Kick off parallel tasks.
   StartParallelCompaction(evacuators, num_tasks);
   // Wait for unfinished and not-yet-started tasks.
   WaitUntilCompactionCompleted(&evacuators[1], num_tasks - 1);
 
   // Finalize local evacuators by merging back all locally cached data.
   for (int i = 0; i < num_tasks; i++) {
     evacuators[i]->Finalize();
     delete evacuators[i];
@@ skipping 757 matching lines @@
     MarkBit mark_bit = Marking::MarkBitFrom(host);
     if (Marking::IsBlack(mark_bit)) {
       RelocInfo rinfo(isolate(), pc, RelocInfo::CODE_TARGET, 0, host);
       RecordRelocSlot(&rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8