[turbofan] Optimize certain chains of Branch into a Switch.

src/compiler/instruction-selector.h

 // Copyright 2014 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_INSTRUCTION_SELECTOR_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_H_
 
 #include <map>
 
 #include "src/compiler/common-operator.h"
@@ skipping 184 matching lines @@
 
   void VisitFinish(Node* node);
   void VisitParameter(Node* node);
   void VisitOsrValue(Node* node);
   void VisitPhi(Node* node);
   void VisitProjection(Node* node);
   void VisitConstant(Node* node);
   void VisitCall(Node* call);
   void VisitGoto(BasicBlock* target);
   void VisitBranch(Node* input, BasicBlock* tbranch, BasicBlock* fbranch);
-  void VisitSwitch(Node* node, BasicBlock** branches, size_t branch_count);
+  void VisitSwitch(Node* node, BasicBlock* default_branch,
+                   BasicBlock** case_branches, int32_t* case_values,
+                   size_t case_count, int32_t min_value, int32_t max_value);
   void VisitReturn(Node* value);
   void VisitThrow(Node* value);
   void VisitDeoptimize(Node* deopt);
 
   // ===========================================================================
 
   Schedule* schedule() const { return schedule_; }
   Linkage* linkage() const { return linkage_; }
   InstructionSequence* sequence() const { return sequence_; }
   Zone* instruction_zone() const { return sequence()->zone(); }
@@ skipping 12 matching lines @@
   BoolVector defined_;
   BoolVector used_;
   IntVector virtual_registers_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_H_