Save/restore only live registers in the generator suspend/resume.

src/interpreter/bytecode-generator.h

 // Copyright 2015 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_INTERPRETER_BYTECODE_GENERATOR_H_
 #define V8_INTERPRETER_BYTECODE_GENERATOR_H_
 
 #include "src/ast/ast.h"
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-label.h"
@@ skipping 118 matching lines @@
   void BuildIndexedJump(Register value, size_t start_index, size_t size,
                         ZoneVector<BytecodeLabel>& targets);
 
   void BuildNewLocalActivationContext();
   void BuildLocalActivationContextInitialization();
   void BuildNewLocalBlockContext(Scope* scope);
   void BuildNewLocalCatchContext(Scope* scope);
   void BuildNewLocalWithContext(Scope* scope);
 
   void BuildGeneratorPrologue();
-  void BuildGeneratorSuspend(Suspend* expr, Register generator);
-  void BuildGeneratorResume(Suspend* expr, Register generator);
+  void BuildGeneratorSuspend(Suspend* expr, Register generator,
+                             RegisterList registers_to_save);
+  void BuildGeneratorResume(Suspend* expr, Register generator,
+                            RegisterList registers_to_restore);
 
   void VisitArgumentsObject(Variable* variable);
   void VisitRestArgumentsArray(Variable* rest);
   void VisitCallSuper(Call* call);
   void VisitClassLiteralProperties(ClassLiteral* expr, Register constructor,
                                    Register prototype);
   void BuildClassLiteralNameProperty(ClassLiteral* expr, Register constructor);
   void BuildClassLiteral(ClassLiteral* expr);
   void VisitThisFunctionVariable(Variable* variable);
   void VisitNewTargetVariable(Variable* variable);
@@ skipping 98 matching lines @@
   ZoneVector<std::pair<NativeFunctionLiteral*, size_t>>
       native_function_literals_;
   ZoneVector<std::pair<ObjectLiteral*, size_t>> object_literals_;
   ZoneVector<std::pair<ArrayLiteral*, size_t>> array_literals_;
 
   ControlScope* execution_control_;
   ContextScope* execution_context_;
   ExpressionResultScope* execution_result_;
 
   BytecodeJumpTable* generator_jump_table_;
+  Register generator_object_;
   Register generator_state_;
   int loop_depth_;
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_GENERATOR_H_