[Interpreter] Implement ForIn in bytecode graph builder.

src/interpreter/interpreter.cc

 // 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.
 
 #include "src/interpreter/interpreter.h"
 
 #include "src/code-factory.h"
 #include "src/compiler.h"
 #include "src/compiler/interpreter-assembler.h"
 #include "src/factory.h"
@@ skipping 1079 matching lines @@
 //
 // Cast the object referenced by the accumulator to a number.
 void Interpreter::DoToNumber(compiler::InterpreterAssembler* assembler) {
   Node* accumulator = __ GetAccumulator();
   Node* result = __ CallRuntime(Runtime::kToNumber, accumulator);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 
-// ToObject
-//
-// Cast the object referenced by the accumulator to a JSObject.
-void Interpreter::DoToObject(compiler::InterpreterAssembler* assembler) {
-  Node* accumulator = __ GetAccumulator();
-  Node* result = __ CallRuntime(Runtime::kToObject, accumulator);
-  __ SetAccumulator(result);
-  __ Dispatch();
-}
-
-
 // Jump <imm8>
 //
 // Jump by number of bytes represented by the immediate operand |imm8|.
 void Interpreter::DoJump(compiler::InterpreterAssembler* assembler) {
   Node* relative_jump = __ BytecodeOperandImm(0);
   __ Jump(relative_jump);
 }
 
 
 // JumpConstant <idx>
@@ skipping 323 matching lines @@
 
 
 // Return
 //
 // Return the value in the accumulator.
 void Interpreter::DoReturn(compiler::InterpreterAssembler* assembler) {
   __ Return();
 }
 
 
-// ForInPrepare <receiver>
+// ForInPrepare <receiver> <cache_type> <cache_array> <cache_length>
 //
-// Returns state for for..in loop execution based on the |receiver| and
-// the property names in the accumulator.
+// Returns state for for..in loop execution based on the object in the
+// accumulator.
+// The |receiver|, |cache_type|, |cache_array|, and |cache_length| are all
+// output
+// parameters.
 void Interpreter::DoForInPrepare(compiler::InterpreterAssembler* assembler) {
-  Node* receiver_reg = __ BytecodeOperandReg(0);
-  Node* receiver = __ LoadRegister(receiver_reg);
-  Node* property_names = __ GetAccumulator();
-  Node* result = __ CallRuntime(Runtime::kInterpreterForInPrepare, receiver,
-                                property_names);
+  // Call runtime to set-up ForInPrepareState
+  Node* object = __ GetAccumulator();
+  Node* result = __ CallRuntime(Runtime::kInterpreterForInPrepare, object);
+
+  for (int i = 0; i < 4; i++) {
+    // 0 == receiver, 1 == cache_type, 2 == cache_array, 3 == cache_length
+    Node* cache_info = __ LoadFixedArrayElement(result, i);
+    Node* cache_info_reg = __ BytecodeOperandReg(i);
+    __ StoreRegister(cache_info, cache_info_reg);
+  }
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 
-// ForInNext <for_in_state> <index>
+// ForInNext <receiver> <cache_type> <cache_array> <index>
 //
-// Returns the next key in a for..in loop. The state associated with the
-// iteration is contained in |for_in_state| and |index| is the current
-// zero-based iteration count.
+// Returns the next key in a for..in loop.
 void Interpreter::DoForInNext(compiler::InterpreterAssembler* assembler) {
-  Node* for_in_state_reg = __ BytecodeOperandReg(0);
-  Node* for_in_state = __ LoadRegister(for_in_state_reg);
-  Node* receiver = __ LoadFixedArrayElement(for_in_state, 0);
-  Node* cache_array = __ LoadFixedArrayElement(for_in_state, 1);
-  Node* cache_type = __ LoadFixedArrayElement(for_in_state, 2);
-  Node* index_reg = __ BytecodeOperandReg(1);
+  Node* receiver_reg = __ BytecodeOperandReg(0);
+  Node* receiver = __ LoadRegister(receiver_reg);
+  Node* cache_type_reg = __ BytecodeOperandReg(1);
+  Node* cache_type = __ LoadRegister(cache_type_reg);
+  Node* cache_array_reg = __ BytecodeOperandReg(2);
+  Node* cache_array = __ LoadRegister(cache_array_reg);
+  Node* index_reg = __ BytecodeOperandReg(3);
   Node* index = __ LoadRegister(index_reg);
   Node* result = __ CallRuntime(Runtime::kForInNext, receiver, cache_array,
                                 cache_type, index);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 
-// ForInDone <for_in_state>
+// ForInDone <index> <cache_length>
 //
-// Returns the next key in a for..in loop. The accumulator contains the current
-// zero-based iteration count and |for_in_state| is the state returned by an
-// earlier invocation of ForInPrepare.
+// Returns the next key in a for..in loop.
 void Interpreter::DoForInDone(compiler::InterpreterAssembler* assembler) {
-  Node* index = __ GetAccumulator();
-  Node* for_in_state_reg = __ BytecodeOperandReg(0);
-  Node* for_in_state = __ LoadRegister(for_in_state_reg);
-  Node* cache_length = __ LoadFixedArrayElement(for_in_state, 3);
+  // TODO(oth): Implement in interpreter assembler.

[rmcilroy, 2015/12/17 15:43:26]

Not sure what this TODO means? What do you want to implement in the interpreter
assembler, what you have here looks fine (or do you mean "Implement inline in
bytecode handler instead of calling out to runtime" ?

[oth, 2015/12/17 19:28:23]

There are among the easiest bytecodes to write in interpreter assembler, smi
inc, and test two smi's for equality. However, I'd like to have lightweight
bytecode instrumentation before we do this so we can see the cycles saved for
the work.

+  Node* index_reg = __ BytecodeOperandReg(0);
+  Node* index = __ LoadRegister(index_reg);
+  Node* cache_length_reg = __ BytecodeOperandReg(1);
+  Node* cache_length = __ LoadRegister(cache_length_reg);
   Node* result = __ CallRuntime(Runtime::kForInDone, index, cache_length);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 
+// ForInStep <index>
+//
+// Increments the loop counter |index|.
+void Interpreter::DoForInStep(compiler::InterpreterAssembler* assembler) {
+  // TODO(oth): Implement in interpreter assembler.

[rmcilroy, 2015/12/17 15:43:27]

ditto

[oth, 2015/12/17 19:28:23]

ditto.

+  Node* index_reg = __ BytecodeOperandReg(0);
+  Node* index = __ LoadRegister(index_reg);
+  Node* result = __ CallRuntime(Runtime::kForInStep, index);
+  __ StoreRegister(result, index_reg);
+  __ Dispatch();
+}
+
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8