[turbofan] Allow tests to enable/disable instruction scheduling.

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 30 matching lines @@
   MachineType type_;
 };
 
 // Instruction selection generates an InstructionSequence for a given Schedule.
 class InstructionSelector final {
  public:
   // Forward declarations.
   class Features;
 
   enum SourcePositionMode { kCallSourcePositions, kAllSourcePositions };
+  enum EnableScheduling { kDisableScheduling, kEnableScheduling };
 
   InstructionSelector(
       Zone* zone, size_t node_count, Linkage* linkage,
       InstructionSequence* sequence, Schedule* schedule,
       SourcePositionTable* source_positions, Frame* frame,
       SourcePositionMode source_position_mode = kCallSourcePositions,
-      Features features = SupportedFeatures());
+      Features features = SupportedFeatures(),
+      EnableScheduling enable_scheduling = FLAG_turbo_instruction_scheduling
+                                               ? kEnableScheduling
+                                               : kDisableScheduling);
 
   // Visit code for the entire graph with the included schedule.
   void SelectInstructions();
 
   void StartBlock(RpoNumber rpo);
   void EndBlock(RpoNumber rpo);
   void AddInstruction(Instruction* instr);
 
   // ===========================================================================
   // ============= Architecture-independent code emission methods. =============
@@ skipping 124 matching lines @@
   int GetEffectLevel(Node* node) const;
 
   int GetVirtualRegister(const Node* node);
   const std::map<NodeId, int> GetVirtualRegistersForTesting() const;
 
   Isolate* isolate() const { return sequence()->isolate(); }
 
  private:
   friend class OperandGenerator;
 
+  bool UseInstructionScheduling() const {
+    return (enable_scheduling_ == kEnableScheduling) &&
+           InstructionScheduler::SchedulerSupported();
+  }
+
   void EmitTableSwitch(const SwitchInfo& sw, InstructionOperand& index_operand);
   void EmitLookupSwitch(const SwitchInfo& sw,
                         InstructionOperand& value_operand);
 
   // Inform the instruction selection that {node} was just defined.
   void MarkAsDefined(Node* node);
 
   // Inform the instruction selection that {node} has at least one use and we
   // will need to generate code for it.
   void MarkAsUsed(Node* node);
@@ skipping 114 matching lines @@
   SourcePositionMode const source_position_mode_;
   Features features_;
   Schedule* const schedule_;
   BasicBlock* current_block_;
   ZoneVector<Instruction*> instructions_;
   BoolVector defined_;
   BoolVector used_;
   IntVector effect_level_;
   IntVector virtual_registers_;
   InstructionScheduler* scheduler_;
+  EnableScheduling enable_scheduling_;
   Frame* frame_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_H_