Add canonicalize optimization for branches.

runtime/vm/flow_graph_optimizer.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_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 140 matching lines @@
       OS::Print("Removing v%"Pd".\n",
                 current->AsDefinition()->ssa_temp_index());
     } else {
       OS::Print("Removing %s\n", current->DebugName());
     }
   }
   it->RemoveCurrentFromGraph();
 }
 
 
-void FlowGraphOptimizer::OptimizeComputations() {
+void FlowGraphOptimizer::Canonicalize() {
   for (intptr_t i = 0; i < block_order_.length(); ++i) {
     BlockEntryInstr* entry = block_order_[i];
     entry->Accept(this);
     for (ForwardInstructionIterator it(entry); !it.Done(); it.Advance()) {
       Instruction* current = it.Current();
       Instruction* replacement = current->Canonicalize(this);
       if (replacement != current) {
         // For non-definitions Canonicalize should return either NULL or
         // this.
         ASSERT((replacement == NULL) || current->IsDefinition());
@@ skipping 1281 matching lines @@
       field,
       instr->ArgumentAt(0)->value(),
       instr->ArgumentAt(1)->value(),
       needs_store_barrier);
   instr->ReplaceWith(store, current_iterator());
   RemovePushArguments(instr);
   return true;
 }
 
 
-// TODO(fschneider): Once we get rid of the distinction between Instruction
-// and computation, this helper can go away.
 static void HandleRelationalOp(FlowGraphOptimizer* optimizer,
                                RelationalOpInstr* comp,
                                Instruction* instr) {
   if (!comp->HasICData() || (comp->ic_data()->NumberOfChecks() == 0)) {
     return;
   }
   const ICData& ic_data = *comp->ic_data();
   if (ic_data.NumberOfChecks() == 1) {
     ASSERT(ic_data.HasOneTarget());
     if (HasOnlyTwoSmis(ic_data)) {
@@ skipping 21 matching lines @@
     comp->set_operands_class_id(kMintCid);
   }
 }
 
 
 void FlowGraphOptimizer::VisitRelationalOp(RelationalOpInstr* instr) {
   HandleRelationalOp(this, instr, instr);
 }
 
 
-// TODO(fschneider): Once we get rid of the distinction between Instruction
-// and computation, this helper can go away.
 template <typename T>
 static void HandleEqualityCompare(FlowGraphOptimizer* optimizer,
                                   EqualityCompareInstr* comp,
                                   T instr,
                                   ForwardInstructionIterator* iterator) {
   // If one of the inputs is null, no ICdata will be collected.
   if (comp->left()->BindsToConstantNull() ||
       comp->right()->BindsToConstantNull()) {
     Token::Kind strict_kind = (comp->kind() == Token::kEQ) ?
         Token::kEQ_STRICT : Token::kNE_STRICT;
@@ skipping 2900 matching lines @@
 
   if (FLAG_trace_constant_propagation) {
     OS::Print("\n==== After constant propagation ====\n");
     FlowGraphPrinter printer(*graph_);
     printer.PrintBlocks();
   }
 }
 
 
 }  // namespace dart