[interpreter] Inline Star on dispatch for some bytecodes

src/interpreter/interpreter-assembler.h

Index: src/interpreter/interpreter-assembler.h
diff --git a/src/interpreter/interpreter-assembler.h b/src/interpreter/interpreter-assembler.h
index 183d4ddaefff1e11306170eea5be41dee460e64a..06b1f999bf74d3610d96b723feee3811ea4a4ff3 100644
--- a/src/interpreter/interpreter-assembler.h
+++ b/src/interpreter/interpreter-assembler.h
@@ -218,14 +218,34 @@ class InterpreterAssembler : public CodeStubAssembler {
   // JumpIfWordNotEqual.
   void JumpConditional(compiler::Node* condition, compiler::Node* jump_offset);
 
-  // Returns BytecodeOffset() advanced by delta bytecodes. Note: this does not
-  // update BytecodeOffset() itself.
+  // Updates and returns BytecodeOffset() advanced by the current bytecode's
+  // size. Traces the exit of the current bytecode.
+  compiler::Node* Advance();
+
+  // Updates and returns BytecodeOffset() advanced by delta bytecodes.
+  // Traces the exit of the current bytecode.
   compiler::Node* Advance(int delta);
   compiler::Node* Advance(compiler::Node* delta);
 
+  // Load the bytecode at |bytecode_offset|.
+  compiler::Node* LoadBytecode(compiler::Node* bytecode_offset);
+
+  // Look ahead for Star and inline it, will bind the next bytecode to dispatch
+  // to, to |target_bytecode| and its offset to |target_offset|.

[rmcilroy, 2016/07/20 10:34:12]

Update comment, remove duplicate "to" and also mention that the new
target_bytecode is returned

[klaasb, 2016/07/20 11:22:55]

Done.

+  compiler::Node* StarDispatchLookahead(compiler::Node* target_bytecode);
+
+  // Build code for Star at |target_offset| and bind |target_offset| to the
+  // next offset after Star

[rmcilroy, 2016/07/20 10:34:12]

Update comment

[klaasb, 2016/07/20 11:22:55]

Done.

+  void InlineStar();
+
   // Starts next instruction dispatch at |new_bytecode_offset|.
   compiler::Node* DispatchTo(compiler::Node* new_bytecode_offset);
 
+  // Dispatch to |target_bytecode| at |new_bytecode_offset|.
+  // |target_bytecode| should be equivalent to loading from the offset.
+  compiler::Node* DispatchToBytecode(compiler::Node* target_bytecode,
+                                     compiler::Node* new_bytecode_offset);
+
   // Dispatch to the bytecode handler with code offset |handler|.
   compiler::Node* DispatchToBytecodeHandler(compiler::Node* handler,
                                             compiler::Node* bytecode_offset);
@@ -238,6 +258,7 @@ class InterpreterAssembler : public CodeStubAssembler {
 
   Bytecode bytecode_;
   OperandScale operand_scale_;
+  CodeStubAssembler::Variable bytecode_offset_;
   CodeStubAssembler::Variable interpreted_frame_pointer_;
   CodeStubAssembler::Variable accumulator_;
   AccumulatorUse accumulator_use_;