Add Zone-based handle allocation interface and reduce use of Isolate-based interfaces.

runtime/vm/flow_graph_allocator.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_allocator.h"
 
 #include "vm/bit_vector.h"
 #include "vm/intermediate_language.h"
 #include "vm/il_printer.h"
 #include "vm/flow_graph.h"
@@ skipping 522 matching lines @@
     use = use->next();
   }
   return true;
 }
 
 
 void FlowGraphAllocator::BuildLiveRanges() {
   const intptr_t block_count = postorder_.length();
   ASSERT(postorder_.Last()->IsGraphEntry());
   BitVector* current_interference_set = NULL;
-  Isolate* isolate = flow_graph_.isolate();
+  Zone* zone = flow_graph_.zone();
   for (intptr_t i = 0; i < (block_count - 1); i++) {
     BlockEntryInstr* block = postorder_[i];
 
     BlockInfo* block_info = BlockInfoAt(block->start_pos());
 
     // For every SSA value that is live out of this block, create an interval
     // that covers the whole block.  It will be shortened if we encounter a
     // definition of this value in this block.
     for (BitVector::Iterator it(liveness_.GetLiveOutSetAt(i));
          !it.Done();
          it.Advance()) {
       LiveRange* range = GetLiveRange(it.Current());
       range->AddUseInterval(block->start_pos(), block->end_pos());
     }
 
     BlockInfo* loop_header = block_info->loop_header();
     if ((loop_header != NULL) && (loop_header->last_block() == block)) {
-      current_interference_set = new(isolate) BitVector(
-          isolate, flow_graph_.max_virtual_register_number());
+      current_interference_set = new(zone) BitVector(
+          zone, flow_graph_.max_virtual_register_number());
       ASSERT(loop_header->backedge_interference() == NULL);
       // All values flowing into the loop header are live at the back-edge and
       // can interfere with phi moves.
       current_interference_set->AddAll(
           liveness_.GetLiveInSet(loop_header->entry()));
       loop_header->set_backedge_interference(
           current_interference_set);
     }
 
     // Connect outgoing phi-moves that were created in NumberInstructions
@@ skipping 1445 matching lines @@
         allocated_head);
     if (pos < intersection) intersection = pos;
   }
   return intersection;
 }
 
 
 void ReachingDefs::AddPhi(PhiInstr* phi) {
   // TODO(johnmccutchan): Fix handling of PhiInstr with PairLocation.
   if (phi->reaching_defs() == NULL) {
-    Isolate* isolate = Isolate::Current();
-    phi->set_reaching_defs(new(isolate) BitVector(
-        isolate, flow_graph_.max_virtual_register_number()));
+    Zone* zone = Thread::Current()->zone();

[siva, 2015/01/23 19:29:26]

Zone* zone = flow_graph_.zone();
here?

[koda, 2015/01/23 21:09:42]

Done.

+    phi->set_reaching_defs(new(zone) BitVector(
+        zone, flow_graph_.max_virtual_register_number()));
 
     // Compute initial set reaching defs set.
     bool depends_on_phi = false;
     for (intptr_t i = 0; i < phi->InputCount(); i++) {
       Definition* input = phi->InputAt(i)->definition();
       if (input->IsPhi()) {
         depends_on_phi = true;
       }
       phi->reaching_defs()->Add(input->ssa_temp_index());
     }
 
     // If this phi depends on another phi then we need fix point iteration.
     if (depends_on_phi) phis_.Add(phi);
   }
 }
 
 
 void ReachingDefs::Compute() {
   // Transitively collect all phis that are used by the given phi.
   for (intptr_t i = 0; i < phis_.length(); i++) {
     // TODO(johnmccutchan): Fix handling of PhiInstr with PairLocation.
     PhiInstr* phi = phis_[i];
 
     // Add all phis that affect this phi to the list.
     for (intptr_t i = 0; i < phi->InputCount(); i++) {
       PhiInstr* input_phi = phi->InputAt(i)->definition()->AsPhi();
       if (input_phi != NULL) {
         AddPhi(input_phi);

[Ivan Posva, 2015/01/23 04:53:04]

We are calling Thread::Current() inside a doubly nested loop here, probably
better to either add the current thread to the ReachingDefs class or pass it
along down to AddPhi from an outer level

[koda, 2015/01/23 14:29:31]

Done. Simply used the flow graph's zone.

Also got rid of a couple of Isolate::Current()->current_zone() the same way.

       }
     }
   }
 
   // Propagate values until fix point is reached.
   bool changed;
   do {
     changed = false;
     for (intptr_t i = 0; i < phis_.length(); i++) {
       PhiInstr* phi = phis_[i];
@@ skipping 85 matching lines @@
          !it.Done();
          it.Advance()) {
       // TODO(johnmccutchan): Fix handling of PhiInstr with PairLocation.
       PhiInstr* phi = it.Current();
       ASSERT(phi->is_alive());
       const intptr_t phi_vreg = phi->ssa_temp_index();
       LiveRange* range = GetLiveRange(phi_vreg);
       if (range->assigned_location().kind() == register_kind_) {
         const intptr_t reg = range->assigned_location().register_code();
 
         if (!reaching_defs_.Get(phi)->Contains(unallocated->vreg())) {

[Ivan Posva, 2015/01/23 04:53:04]

ditto for Get(phi)

[koda, 2015/01/23 14:29:31]

Get doesn't need any zone.

           used_on_backedge[reg] = true;
         }
       }
     }
 
     if (used_on_backedge[candidate]) {
       TRACE_ALLOC(OS::Print(
           "considering %s for v%" Pd ": has interference on the back edge"
           " {loop [%" Pd ", %" Pd ")}\n",
           MakeRegisterLocation(candidate).Name(),
@@ skipping 797 matching lines @@
     OS::Print("-- [after ssa allocator] ir [%s] -------------\n",
               function.ToFullyQualifiedCString());
     FlowGraphPrinter printer(flow_graph_, true);
     printer.PrintBlocks();
     OS::Print("----------------------------------------------\n");
   }
 }
 
 
 }  // namespace dart