Merge V8 5.3.332.45. DO NOT MERGE
Test: Manual
FPIIM-449
Change-Id: Id3254828b068abdea3cb10442e0172a8c9a98e03
(cherry picked from commit 13e2dadd00298019ed862f2b2fc5068bba730bcf)
diff --git a/src/interpreter/bytecode-label.h b/src/interpreter/bytecode-label.h
new file mode 100644
index 0000000..2f89c48
--- /dev/null
+++ b/src/interpreter/bytecode-label.h
@@ -0,0 +1,56 @@
+// 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_LABEL_H_
+#define V8_INTERPRETER_BYTECODE_LABEL_H_
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+// A label representing a branch target in a bytecode array. When a
+// label is bound, it represents a known position in the bytecode
+// array. For labels that are forward references there can be at most
+// one reference whilst it is unbound.
+class BytecodeLabel final {
+ public:
+ BytecodeLabel() : bound_(false), offset_(kInvalidOffset) {}
+
+ bool is_bound() const { return bound_; }
+ size_t offset() const { return offset_; }
+
+ private:
+ static const size_t kInvalidOffset = static_cast<size_t>(-1);
+
+ void bind_to(size_t offset) {
+ DCHECK(!bound_ && offset != kInvalidOffset);
+ offset_ = offset;
+ bound_ = true;
+ }
+
+ void set_referrer(size_t offset) {
+ DCHECK(!bound_ && offset != kInvalidOffset && offset_ == kInvalidOffset);
+ offset_ = offset;
+ }
+
+ bool is_forward_target() const {
+ return offset() != kInvalidOffset && !is_bound();
+ }
+
+ // There are three states for a label:
+ // bound_ offset_
+ // UNSET false kInvalidOffset
+ // FORWARD_TARGET false Offset of referring jump
+ // BACKWARD_TARGET true Offset of label in bytecode array when bound
+ bool bound_;
+ size_t offset_;
+
+ friend class BytecodeArrayWriter;
+};
+
+} // namespace interpreter
+} // namespace internal
+} // namespace v8
+
+#endif // V8_INTERPRETER_BYTECODE_LABEL_H_