Refactoring such that loop builders only call into the HOsrBuilder if

compiling for OSR.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/25039003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16990 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-osr.cc

@@ -37,19 +37,8 @@ bool HOsrBuilder::HasOsrEntryAt(IterationStatement* statement) {
 }
 
 
-// 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();
@@ -113,7 +102,7 @@ HBasicBlock* HOsrBuilder::BuildPossibleOsrLoopEntry(
   builder_->set_current_block(loop_predecessor);
 
   // Create the final loop entry
-  osr_loop_entry_ = BuildLoopEntry();
+  osr_loop_entry_ = builder_->BuildLoopEntry();
   return osr_loop_entry_;
 }
 

src/hydrogen-osr.h

@@ -45,9 +45,10 @@ class HOsrBuilder : public ZoneObject {
       osr_entry_(NULL),
       osr_loop_entry_(NULL),
       osr_values_(NULL) { }
+
   // Creates the loop entry block for the given statement, setting up OSR
   // entries as necessary, and sets the current block to the new block.
-  HBasicBlock* BuildPossibleOsrLoopEntry(IterationStatement* statement);
+  HBasicBlock* BuildOsrLoopEntry(IterationStatement* statement);
 
   // Process the hydrogen graph after it has been completed, performing
   // any OSR-specific cleanups or changes.
@@ -61,10 +62,9 @@ class HOsrBuilder : public ZoneObject {
     return unoptimized_frame_slots_;
   }
 
- private:
-  HBasicBlock* BuildLoopEntry();
   bool HasOsrEntryAt(IterationStatement* statement);
 
+ private:
   int unoptimized_frame_slots_;
   HOptimizedGraphBuilder* builder_;
   HBasicBlock* osr_entry_;

src/hydrogen.cc

@@ -2246,6 +2246,24 @@ HBasicBlock* HOptimizedGraphBuilder::CreateLoop(IterationStatement* statement,
 }
 
 
+// Build a new loop header block and set it as the current block.
+HBasicBlock* HOptimizedGraphBuilder::BuildLoopEntry() {
+  HBasicBlock* loop_entry = CreateLoopHeaderBlock();
+  current_block()->Goto(loop_entry);
+  set_current_block(loop_entry);
+  return loop_entry;
+}
+
+
+HBasicBlock* HOptimizedGraphBuilder::BuildLoopEntry(
+    IterationStatement* statement) {
+  HBasicBlock* loop_entry = osr()->HasOsrEntryAt(statement)
+      ? osr()->BuildOsrLoopEntry(statement)
+      : BuildLoopEntry();
+  return loop_entry;
+}
+
+
 void HBasicBlock::FinishExit(HControlInstruction* instruction) {
   Finish(instruction);
   ClearEnvironment();
@@ -3087,7 +3105,7 @@ bool HOptimizedGraphBuilder::BuildGraph() {
   type_info->set_inlined_type_change_checksum(composite_checksum);
 
   // Perform any necessary OSR-specific cleanups or changes to the graph.
-  osr_->FinishGraph();
+  osr()->FinishGraph();
 
   return true;
 }
@@ -3670,7 +3688,7 @@ void HOptimizedGraphBuilder::VisitDoWhileStatement(DoWhileStatement* stmt) {
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   ASSERT(current_block() != NULL);
-  HBasicBlock* loop_entry = osr_->BuildPossibleOsrLoopEntry(stmt);
+  HBasicBlock* loop_entry = BuildLoopEntry(stmt);
 
   BreakAndContinueInfo break_info(stmt);
   CHECK_BAILOUT(VisitLoopBody(stmt, loop_entry, &break_info));
@@ -3709,7 +3727,7 @@ void HOptimizedGraphBuilder::VisitWhileStatement(WhileStatement* stmt) {
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   ASSERT(current_block() != NULL);
-  HBasicBlock* loop_entry = osr_->BuildPossibleOsrLoopEntry(stmt);
+  HBasicBlock* loop_entry = BuildLoopEntry(stmt);
 
   // If the condition is constant true, do not generate a branch.
   HBasicBlock* loop_successor = NULL;
@@ -3751,7 +3769,7 @@ void HOptimizedGraphBuilder::VisitForStatement(ForStatement* stmt) {
     CHECK_ALIVE(Visit(stmt->init()));
   }
   ASSERT(current_block() != NULL);
-  HBasicBlock* loop_entry = osr_->BuildPossibleOsrLoopEntry(stmt);
+  HBasicBlock* loop_entry = BuildLoopEntry(stmt);
 
   HBasicBlock* loop_successor = NULL;
   if (stmt->cond() != NULL) {
@@ -3834,7 +3852,7 @@ void HOptimizedGraphBuilder::VisitForInStatement(ForInStatement* stmt) {
   HForInCacheArray::cast(array)->set_index_cache(
       HForInCacheArray::cast(index_cache));
 
-  HBasicBlock* loop_entry = osr_->BuildPossibleOsrLoopEntry(stmt);
+  HBasicBlock* loop_entry = BuildLoopEntry(stmt);
 
   HValue* index = environment()->ExpressionStackAt(0);
   HValue* limit = environment()->ExpressionStackAt(1);

src/hydrogen.h

@@ -1781,6 +1781,8 @@ class HOptimizedGraphBuilder V8_FINAL
 
   HValue* context() { return environment()->context(); }
 
+  HOsrBuilder* osr() const { return osr_; }
+
   void Bailout(BailoutReason reason);
 
   HBasicBlock* CreateJoin(HBasicBlock* first,
@@ -1886,6 +1888,12 @@ class HOptimizedGraphBuilder V8_FINAL
                           HBasicBlock* loop_successor,
                           HBasicBlock* break_block);
 
+  // Build a loop entry
+  HBasicBlock* BuildLoopEntry();
+
+  // Builds a loop entry respectful of OSR requirements
+  HBasicBlock* BuildLoopEntry(IterationStatement* statement);
+
   HBasicBlock* JoinContinue(IterationStatement* statement,
                             HBasicBlock* exit_block,
                             HBasicBlock* continue_block);