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

src/compiler/raw-machine-assembler.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_RAW_MACHINE_ASSEMBLER_H_
 #define V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph-builder.h"
 #include "src/compiler/linkage.h"
@@ skipping 29 matching lines @@
     bool bound_;
     friend class RawMachineAssembler;
     DISALLOW_COPY_AND_ASSIGN(Label);
   };
 
   RawMachineAssembler(Isolate* isolate, Graph* graph,
                       const MachineSignature* machine_sig,
                       MachineType word = kMachPtr,
                       MachineOperatorBuilder::Flags flags =
                           MachineOperatorBuilder::Flag::kNoFlags);
+
+  RawMachineAssembler(Isolate* isolate, Graph* graph,
+                      const MachineSignature* machine_sig, MachineType word,
+                      MachineOperatorBuilder::Flags flags,
+                      CallDescriptor* call_descriptor);

[oth, 2015/07/15 13:22:01]

The two constructors for RawMachineAssembler could be rolled into one, but
adding a default parameter CallDescriptor* call_descriptor = nullptr to the
existing constructor.

[rmcilroy, 2015/07/15 16:55:58]

The existing constructor passes Linkage::GetSimplifiedCDescriptor(graph->zone(),
machine_sig) to call_descriptor, so a nullptr default wouldn't really work the
same way unfortunately (unless I explicitly checked for nullptr in the
constructor, but that seems nasty).

However, I agree it would be nice to avoid the double constructors, so I've
refactored the existing RawMachineAssembler to explicitly pass the correct
CallDescriptor instead. I moved this to a seperate CL at
https://codereview.chromium.org/1235313002, let me know what you think?

+
   ~RawMachineAssembler() override {}
 
   Zone* zone() const { return graph()->zone(); }
   MachineOperatorBuilder* machine() { return &machine_; }
   CommonOperatorBuilder* common() { return &common_; }
   CallDescriptor* call_descriptor() const { return call_descriptor_; }
   size_t parameter_count() const { return machine_sig_->parameter_count(); }
   const MachineSignature* machine_sig() const { return machine_sig_; }
 
   Node* UndefinedConstant() {
@@ skipping 442 matching lines @@
   Node* Phi(MachineType type, Node* n1, Node* n2, Node* n3) {
     return NewNode(common()->Phi(type, 3), n1, n2, n3);
   }
   Node* Phi(MachineType type, Node* n1, Node* n2, Node* n3, Node* n4) {
     return NewNode(common()->Phi(type, 4), n1, n2, n3, n4);
   }
 
   // MachineAssembler is invalid after export.
   Schedule* Export();
 
+  Schedule* schedule() {
+    DCHECK(ScheduleValid());
+    return schedule_;
+  }
+
+  BasicBlock* CurrentBlock();
+
  protected:
   Node* MakeNode(const Operator* op, int input_count, Node** inputs,
                  bool incomplete) final;
 
   bool ScheduleValid() { return schedule_ != NULL; }
 
-  Schedule* schedule() {
-    DCHECK(ScheduleValid());
-    return schedule_;
-  }
-
  private:
   BasicBlock* Use(Label* label);
   BasicBlock* EnsureBlock(Label* label);
-  BasicBlock* CurrentBlock();
 
   Schedule* schedule_;
   MachineOperatorBuilder machine_;
   CommonOperatorBuilder common_;
   const MachineSignature* machine_sig_;
   CallDescriptor* call_descriptor_;
   Node** parameters_;
   BasicBlock* current_block_;
 
   DISALLOW_COPY_AND_ASSIGN(RawMachineAssembler);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_