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Unified Diff: src/virtual-frame.h

Issue 115347: Reduce the memory used by frame elements from two words to one by... (Closed) Base URL: http://v8.googlecode.com/svn/branches/bleeding_edge/
Patch Set: Created 11 years, 7 months ago
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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
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