Use hash map for the SSA builder constant pool.

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/growable_array.h"
@@ skipping 75 matching lines @@
 
 GrowableArray<BlockEntryInstr*>* FlowGraph::CodegenBlockOrder(
     bool is_optimized) {
   return ShouldReorderBlocks(parsed_function().function(), is_optimized)
       ? &optimized_block_order_
       : &reverse_postorder_;
 }
 
 
 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())) {
-      return constant;
-    }
+  ConstantInstr* constant = constant_instr_pool_.Lookup(object);
+  if (constant == NULL) {
+    // Otherwise, allocate and add it to the pool.
+    constant = new(isolate()) ConstantInstr(object);
+    constant->set_ssa_temp_index(alloc_ssa_temp_index());
+    AddToInitialDefinitions(constant);
+    constant_instr_pool_.Insert(constant);
   }
-  // Otherwise, allocate and add it to the pool.
-  ConstantInstr* constant = new(isolate()) ConstantInstr(object);
-  constant->set_ssa_temp_index(alloc_ssa_temp_index());
-  AddToInitialDefinitions(constant);
   return constant;
 }
 
 
 void FlowGraph::AddToInitialDefinitions(Definition* defn) {
   // TODO(zerny): Set previous to the graph entry so it is accessible by
   // GetBlock. Remove this once there is a direct pointer to the block.
   defn->set_previous(graph_entry_);
   graph_entry_->initial_definitions()->Add(defn);
 }
@@ skipping 1139 matching lines @@
 }
 
 
 bool BlockEffects::IsSideEffectFreePath(BlockEntryInstr* from,
                                         BlockEntryInstr* to) const {
   return available_at_[to->postorder_number()]->Contains(
       from->postorder_number());
 }
 
 }  // namespace dart