Implement a variation of scalar replacement for non-escaping allocations.

runtime/vm/flow_graph.cc

 // Copyright (c) 2012, 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.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/intermediate_language.h"
 #include "vm/longjump.h"
@@ skipping 11 matching lines @@
     current_ssa_temp_index_(0),
     max_block_id_(max_block_id),
     parsed_function_(builder.parsed_function()),
     num_copied_params_(builder.num_copied_params()),
     num_non_copied_params_(builder.num_non_copied_params()),
     num_stack_locals_(builder.num_stack_locals()),
     graph_entry_(graph_entry),
     preorder_(),
     postorder_(),
     reverse_postorder_(),
-    block_effects_(NULL) {
+    block_effects_(NULL),
+    licm_allowed_(true) {
   DiscoverBlocks();
 }
 
 
 ConstantInstr* FlowGraph::GetConstant(const Object& object) {
   // Check if the constant is already in the pool.
   GrowableArray<Definition*>* pool = graph_entry_->initial_definitions();
   for (intptr_t i = 0; i < pool->length(); ++i) {
     ConstantInstr* constant = (*pool)[i]->AsConstant();
     if ((constant != NULL) && (constant->value().raw() == object.raw())) {
@@ skipping 1013 matching lines @@
 }
 
 
 bool BlockEffects::IsSideEffectFreePath(BlockEntryInstr* from,
                                         BlockEntryInstr* to) const {
   return available_at_[to->postorder_number()]->Contains(
       from->postorder_number());
 }
 
 }  // namespace dart