[interpreter] Introduce bytecode generation pipeline.

src/interpreter/bytecode-pipeline.h

Index: src/interpreter/bytecode-pipeline.h
diff --git a/src/interpreter/bytecode-pipeline.h b/src/interpreter/bytecode-pipeline.h
new file mode 100644
index 0000000000000000000000000000000000000000..ade712c92c323db41759cd17766ca7e5bfb5f361
--- /dev/null
+++ b/src/interpreter/bytecode-pipeline.h
@@ -0,0 +1,138 @@
+// 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_PIPELINE_H_
+#define V8_INTERPRETER_BYTECODE_PIPELINE_H_
+
+#include "src/interpreter/bytecode-register-allocator.h"
+#include "src/interpreter/bytecodes.h"
+#include "src/zone-containers.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+class BytecodeNode;
+class BytecodeSourceInfo;
+
+// Interface for bytecode pipeline stages.
+class BytecodePipelineStage {
+ public:
+  virtual ~BytecodePipelineStage() {}
+
+  // Write bytecode node |node| into pipeline. The node is only valid
+  // for the duration of the call. Callee's should clone it if
+  // deferring Write() to the next stage.
+  virtual void Write(BytecodeNode* node) = 0;
+
+  // Flush state for bytecode array offset calculation. Returns the
+  // current size of bytecode array.
+  virtual size_t FlushForOffset() = 0;
+
+  // Flush state to terminate basic block.
+  virtual void FlushBasicBlock() = 0;
+};
+
+// Source code position information.
+class BytecodeSourceInfo final {
+ public:
+  static const int kUninitializedPosition = -1;
+
+  BytecodeSourceInfo(int position = kUninitializedPosition,
+                     bool is_statement = false)
+      : source_position_(position), is_statement_(is_statement) {}
+
+  // Combine later source info with current.
+  void Update(const BytecodeSourceInfo& entry);
+
+  int source_position() const {
+    DCHECK(is_valid());
+    return source_position_;
+  }
+
+  bool is_statement() const { return is_valid() && is_statement_; }
+
+  bool is_valid() const { return source_position_ != kUninitializedPosition; }
+  void set_invalid() { source_position_ = kUninitializedPosition; }
+
+  bool operator==(const BytecodeSourceInfo& other) const {
+    return source_position_ == other.source_position_ &&
+           is_statement_ == other.is_statement_;
+  }
+  bool operator!=(const BytecodeSourceInfo& other) const {
+    return source_position_ != other.source_position_ ||
+           is_statement_ != other.is_statement_;
+  }
+
+ private:
+  int source_position_;
+  bool is_statement_;
+
+  DISALLOW_COPY_AND_ASSIGN(BytecodeSourceInfo);
+};
+
+// A container for a generated bytecode, it's operands, and source information.
+// These must be allocated by a BytecodeNodeAllocator instance.
+class BytecodeNode final : ZoneObject {
+ public:
+  explicit BytecodeNode(Bytecode bytecode = Bytecode::kIllegal);
+  BytecodeNode(Bytecode bytecode, uint32_t operand0,
+               OperandScale operand_scale);
+  BytecodeNode(Bytecode bytecode, uint32_t operand0, uint32_t operand1,
+               OperandScale operand_scale);
+  BytecodeNode(Bytecode bytecode, uint32_t operand0, uint32_t operand1,
+               uint32_t operand2, OperandScale operand_scale);
+  BytecodeNode(Bytecode bytecode, uint32_t operand0, uint32_t operand1,
+               uint32_t operand2, uint32_t operand3,
+               OperandScale operand_scale);
+
+  void set_bytecode(Bytecode bytecode);
+  void set_bytecode(Bytecode bytecode, uint32_t operand0,
+                    OperandScale operand_scale);
+
+  // Clone |other|.
+  void Clone(const BytecodeNode* const other);
+
+  // Print to stream |os|.
+  void Print(std::ostream& os) const;
+
+  // Return the size when this node is serialized to a bytecode array.
+  size_t Size() const;
+
+  Bytecode bytecode() const { return bytecode_; }
+
+  uint32_t operand(int i) const {
+    DCHECK_LT(i, operand_count());
+    return operands_[i];
+  }
+  uint32_t* operands() { return operands_; }
+  const uint32_t* operands() const { return operands_; }
+
+  int operand_count() const { return Bytecodes::NumberOfOperands(bytecode_); }
+  OperandScale operand_scale() const { return operand_scale_; }
+
+  const BytecodeSourceInfo& source_info() const { return source_info_; }
+  BytecodeSourceInfo& source_info() { return source_info_; }
+
+  bool operator==(const BytecodeNode& other) const;
+  bool operator!=(const BytecodeNode& other) const { return !(*this == other); }
+
+ private:
+  static const int kInvalidPosition = kMinInt;
+  static const size_t kMaxOperands = 4;
+
+  Bytecode bytecode_;
+  uint32_t operands_[kMaxOperands];
+  OperandScale operand_scale_;
+  BytecodeSourceInfo source_info_;
+};
+
+std::ostream& operator<<(std::ostream& os, const BytecodeSourceInfo& info);
+std::ostream& operator<<(std::ostream& os, const BytecodeNode& node);
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTERPRETER_BYTECODE_PIPELINE_H_