Start immediate dominator propagation at entry to floating control.

src/compiler/scheduler.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_SCHEDULER_H_
 #define V8_COMPILER_SCHEDULER_H_
 
 #include "src/v8.h"
 
 #include "src/compiler/opcodes.h"
@@ skipping 60 matching lines @@
   inline SchedulerData* GetData(Node* node);
 
   Placement GetPlacement(Node* node);
   void UpdatePlacement(Node* node, Placement placement);
 
   inline bool IsCoupledControlEdge(Node* node, int index);
   void IncrementUnscheduledUseCount(Node* node, int index, Node* from);
   void DecrementUnscheduledUseCount(Node* node, int index, Node* from);
 
   BasicBlock* GetCommonDominator(BasicBlock* b1, BasicBlock* b2);
+  void PropagateImmediateDominators(BasicBlock* block);
 
   // Phase 1: Build control-flow graph.
   friend class CFGBuilder;
   void BuildCFG();
 
   // Phase 2: Compute special RPO and dominator tree.
   friend class SpecialRPONumberer;
   void ComputeSpecialRPONumbering();
   void GenerateImmediateDominatorTree();
 
@@ skipping 14 matching lines @@
 
   void FuseFloatingControl(BasicBlock* block, Node* node);
   void MovePlannedNodes(BasicBlock* from, BasicBlock* to);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SCHEDULER_H_