Reduce the memory used by frame elements from two words to one by...

src/virtual-frame.h

Index: src/virtual-frame.h
===================================================================
--- src/virtual-frame.h	(revision 1947)
+++ src/virtual-frame.h	(working copy)
@@ -29,205 +29,8 @@
 #define V8_VIRTUAL_FRAME_H_
 
 #include "macro-assembler.h"
+#include "frame-element.h"

[Kevin Millikin (Chromium), 2009/05/14 11:29:02]

Again.

[Mads Ager (chromium), 2009/05/14 11:42:40]

Done.

 
-namespace v8 { namespace internal {
-
-// -------------------------------------------------------------------------
-// Virtual frame elements
-//
-// The internal elements of the virtual frames.  There are several kinds of
-// elements:
-//   * Invalid: elements that are uninitialized or not actually part
-//     of the virtual frame.  They should not be read.
-//   * Memory: an element that resides in the actual frame.  Its address is
-//     given by its position in the virtual frame.
-//   * Register: an element that resides in a register.
-//   * Constant: an element whose value is known at compile time.
-
-class FrameElement BASE_EMBEDDED {
- public:
-  enum SyncFlag {
-    NOT_SYNCED,
-    SYNCED
-  };
-
-  // The default constructor creates an invalid frame element.
-  FrameElement()
-      : static_type_(), type_(INVALID), copied_(false), synced_(false) {
-    data_.reg_ = no_reg;
-  }
-
-  // Factory function to construct an invalid frame element.
-  static FrameElement InvalidElement() {
-    FrameElement result;
-    return result;
-  }
-
-  // Factory function to construct an in-memory frame element.
-  static FrameElement MemoryElement() {
-    FrameElement result(MEMORY, no_reg, SYNCED);
-    return result;
-  }
-
-  // Factory function to construct an in-register frame element.
-  static FrameElement RegisterElement(Register reg,
-                                      SyncFlag is_synced,
-                                      StaticType static_type = StaticType()) {
-    return FrameElement(REGISTER, reg, is_synced, static_type);
-  }
-
-  // Factory function to construct a frame element whose value is known at
-  // compile time.
-  static FrameElement ConstantElement(Handle<Object> value,
-                                      SyncFlag is_synced) {
-    FrameElement result(value, is_synced);
-    return result;
-  }
-
-  bool is_synced() const { return synced_; }
-
-  void set_sync() {
-    ASSERT(type() != MEMORY);
-    synced_ = true;
-  }
-
-  void clear_sync() {
-    ASSERT(type() != MEMORY);
-    synced_ = false;
-  }
-
-  bool is_valid() const { return type() != INVALID; }
-  bool is_memory() const { return type() == MEMORY; }
-  bool is_register() const { return type() == REGISTER; }
-  bool is_constant() const { return type() == CONSTANT; }
-  bool is_copy() const { return type() == COPY; }
-
-  bool is_copied() const { return copied_; }
-  void set_copied() { copied_ = true; }
-  void clear_copied() { copied_ = false; }
-
-  Register reg() const {
-    ASSERT(is_register());
-    return data_.reg_;
-  }
-
-  Handle<Object> handle() const {
-    ASSERT(is_constant());
-    return Handle<Object>(data_.handle_);
-  }
-
-  int index() const {
-    ASSERT(is_copy());
-    return data_.index_;
-  }
-
-  StaticType static_type() { return static_type_; }
-
-  void set_static_type(StaticType static_type) {
-    // TODO(lrn): If it's s copy, it would be better to update the real one,
-    // but we can't from here. The caller must handle this.
-    static_type_ = static_type;
-  }
-
-  // True if the frame elements are identical (all data members).
-  bool Equals(FrameElement other);
-
-  // Given a pair of non-null frame element pointers, return one of them
-  // as an entry frame candidate or null if they are incompatible.
-  FrameElement* Combine(FrameElement* other) {
-    // If either is invalid, the result is.
-    if (!is_valid()) return this;
-    if (!other->is_valid()) return other;
-
-    // If they do not have the exact same location we reallocate.
-    bool not_same_location =
-        (type_ != other->type_) ||
-        (is_register() && !reg().is(other->reg())) ||
-        (is_constant() && !handle().is_identical_to(other->handle())) ||
-        (is_copy() && index() != other->index());
-    if (not_same_location) return NULL;
-
-    // If either is unsynced, the result is.  The result static type is
-    // the merge of the static types.  It's safe to set it on one of the
-    // frame elements, and harmless too (because we are only going to
-    // merge the reaching frames and will ensure that the types are
-    // coherent, and changing the static type does not emit code).
-    FrameElement* result = is_synced() ? other : this;
-    result->set_static_type(static_type().merge(other->static_type()));
-    return result;
-  }
-
- private:
-  enum Type {
-    INVALID,
-    MEMORY,
-    REGISTER,
-    CONSTANT,
-    COPY
-  };
-
-  Type type() const { return static_cast<Type>(type_); }
-
-  StaticType static_type_;
-
-  // The element's type.
-  byte type_;
-
-  bool copied_;
-
-  // The element's dirty-bit. The dirty bit can be cleared
-  // for non-memory elements to indicate that the element agrees with
-  // the value in memory in the actual frame.
-  bool synced_;
-
-  union {
-    Register reg_;
-    Object** handle_;
-    int index_;
-  } data_;
-
-  // Used to construct memory and register elements.
-  FrameElement(Type type, Register reg, SyncFlag is_synced)
-      : static_type_(),
-        type_(type),
-        copied_(false),
-        synced_(is_synced  != NOT_SYNCED) {
-    data_.reg_ = reg;
-  }
-
-  FrameElement(Type type, Register reg, SyncFlag is_synced, StaticType stype)
-      : static_type_(stype),
-        type_(type),
-        copied_(false),
-        synced_(is_synced != NOT_SYNCED) {
-    data_.reg_ = reg;
-  }
-
-  // Used to construct constant elements.
-  FrameElement(Handle<Object> value, SyncFlag is_synced)
-      : static_type_(StaticType::TypeOf(*value)),
-        type_(CONSTANT),
-        copied_(false),
-        synced_(is_synced != NOT_SYNCED) {
-    data_.handle_ = value.location();
-  }
-
-  void set_index(int new_index) {
-    ASSERT(is_copy());
-    data_.index_ = new_index;
-  }
-
-  void set_reg(Register new_reg) {
-    ASSERT(is_register());
-    data_.reg_ = new_reg;
-  }
-
-  friend class VirtualFrame;
-};
-
-
-} }  // namespace v8::internal
-
 #if V8_TARGET_ARCH_IA32
 #include "ia32/virtual-frame-ia32.h"
 #elif V8_TARGET_ARCH_X64