[interpreter] Add basic framework for bytecode handler code generation.

src/compiler/interpreter-assembler.h

Index: src/compiler/interpreter-assembler.h
diff --git a/src/compiler/interpreter-assembler.h b/src/compiler/interpreter-assembler.h
new file mode 100644
index 0000000000000000000000000000000000000000..8852cf3fa258ee5ace750b65ca13620d5ab943ed
--- /dev/null
+++ b/src/compiler/interpreter-assembler.h
@@ -0,0 +1,98 @@
+// 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_COMPILER_INTERPRETER_CODEGEN_H_
+#define V8_COMPILER_INTERPRETER_CODEGEN_H_
+
+#include "src/interpreter/bytecodes.h"

[Michael Starzinger, 2015/07/17 13:20:58]

Can we add the same comment that is in pipeline.h to this file as well?

// Clients of this interface shouldn't depend on lots of compiler internals.
// Do not include anything from src/compiler here!

[rmcilroy, 2015/07/21 11:13:21]

Done. Also added similar comments for src/interpreter/interpreter.h and
src/interpreter/bytecodes.h since they should be the only entrypoints into the
interpreter for now.

+#include "src/smart-pointers.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+class Zone;
+
+namespace compiler {
+
+class CallDescriptor;
+class CommonOperatorBuilder;
+class Graph;
+class MachineOperatorBuilder;
+class Node;
+class Operator;
+class RawMachineAssembler;
+class Schedule;
+
+class InterpreterAssembler {
+ public:
+  InterpreterAssembler(Isolate* isolate, Zone* zone,

[Michael Starzinger, 2015/07/17 13:20:58]

Do you think it makes sense to add unit tests for the InterpreterAssembler? I am
mostly thinking about unit tests for the builder functions (e.g. LoadRegister,
StoreRegister and friends), not the code generation itself.

If you agree that having unit tests has a benefit, then I would be fine with
just having one or two of them for now, so that we at least have the unit test
file ready for the tricky functions that we actually want to test. For TurboFan
unit tests we are not looking for full coverage, just for covering the thing
that are crucial and have potential to cause breakage while refactoring.

[rmcilroy, 2015/07/21 11:13:21]

Yes this probably makes sense, although I'm not exactly sure what I can test for
the LoadRegister/StoreRegister etc. type functions, but I'll have a go and add
this for the next patch set if it works.

+                       interpreter::Bytecode bytecode);
+  virtual ~InterpreterAssembler();
+
+  Handle<Code> GenerateCode();
+
+  // Constants.
+  Node* Int32Constant(int value);
+  Node* NumberConstant(double value);
+
+  // Returns the bytecode argument |index| for the current bytecode.
+  Node* BytecodeArg(int index);
+
+  // Loads from and stores to the interpreter register file.
+  Node* LoadRegister(int index);
+  Node* LoadRegister(Node* index);
+  void StoreRegister(Node* value, int index);
+  void StoreRegister(Node* value, Node* index);
+
+  // Function return.
+  void Return(Node* value);
+
+  // Dispatch to the bytecode.
+  void Dispatch();
+
+  // Specifies the parameter number used to thread fixed register data through
+  // interpreter dispatches.
+  static const int kBytecodePointerParameter = 0;
+  static const int kDispatchTablePointerParameter = 1;
+
+ private:
+  // Returns the pointer to the current bytecode.
+  Node* BytecodePointer();
+  // Returns the pointer to first entry in the interpreter dispatch table.
+  Node* DispatchTablePointer();
+  // Returns the frame pointer for the current function.
+  Node* FramePointer();
+
+  // Returns the offset of register |index|.
+  Node* RegisterFrameOffset(int index);
+  Node* RegisterFrameOffset(Node* index);
+
+  // Returns BytecodePointer() advanced by delta bytecodes. Note: this does not
+  // update BytecodePointer() itself.
+  Node* Advance(int delta);
+
+  // Returns the a call descriptor for interpreter dispatch.
+  const CallDescriptor* GetCallDiscriptorForDispatch();
+
+  // Private helpers which delegate to RawMachineAssembler.
+  Isolate* isolate();
+  Graph* graph();
+  Schedule* schedule();
+  MachineOperatorBuilder* machine();
+  CommonOperatorBuilder* common();
+
+  Zone* zone_;  // Not owned.
+  interpreter::Bytecode bytecode_;
+  SmartPointer<RawMachineAssembler> raw_assembler_;
+  bool code_generated_;
+
+  DISALLOW_COPY_AND_ASSIGN(InterpreterAssembler);
+};
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_INTERPRETER_CODEGEN_H_