Only call into the HOsrBuilder if required for OSR.

src/hydrogen-osr.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 19 matching lines @@
 
 namespace v8 {
 namespace internal {
 
 // True iff. we are compiling for OSR and the statement is the entry.
 bool HOsrBuilder::HasOsrEntryAt(IterationStatement* statement) {
   return statement->OsrEntryId() == builder_->current_info()->osr_ast_id();
 }
 
 
-// Build a new loop header block and set it as the current block.
-HBasicBlock *HOsrBuilder::BuildLoopEntry() {
-  HBasicBlock* loop_entry = builder_->CreateLoopHeaderBlock();
-  builder_->current_block()->Goto(loop_entry);
-  builder_->set_current_block(loop_entry);
-  return loop_entry;
-}
-
-
-HBasicBlock* HOsrBuilder::BuildPossibleOsrLoopEntry(
-    IterationStatement* statement) {
-  // Check if there is an OSR here first.
-  if (!HasOsrEntryAt(statement)) return BuildLoopEntry();
+HBasicBlock* HOsrBuilder::BuildOsrLoopEntry(IterationStatement* statement) {
+  ASSERT(HasOsrEntryAt(statement));
 
   Zone* zone = builder_->zone();
   HGraph* graph = builder_->graph();
 
   // only one OSR point per compile is allowed.
   ASSERT(graph->osr() == NULL);
 
   // remember this builder as the one OSR builder in the graph.
   graph->set_osr(this);
 
@@ skipping 43 matching lines @@
 
   builder_->Add<HSimulate>(osr_entry_id);
   builder_->Add<HOsrEntry>(osr_entry_id);
   HContext* context = builder_->Add<HContext>();
   environment->BindContext(context);
   builder_->current_block()->Goto(loop_predecessor);
   loop_predecessor->SetJoinId(statement->EntryId());
   builder_->set_current_block(loop_predecessor);
 
   // Create the final loop entry
-  osr_loop_entry_ = BuildLoopEntry();
+  osr_loop_entry_ = builder_->BuildLoopEntry();
   return osr_loop_entry_;
 }
 
 
 void HOsrBuilder::FinishGraph() {
   // do nothing for now.
 }
 
 
 void HOsrBuilder::FinishOsrValues() {
   const ZoneList<HPhi*>* phis = osr_loop_entry_->phis();
   for (int j = 0; j < phis->length(); j++) {
     HPhi* phi = phis->at(j);
     if (phi->HasMergedIndex()) {
       osr_values_->at(phi->merged_index())->set_incoming_value(phi);
     }
   }
 }
 
 } }  // namespace v8::internal