Update V8 to r7427: Initial merge by git
As required by WebKit r82507
Change-Id: I7ae83ef3f689356043b4929255b7c1dd31d8c5df
diff --git a/src/small-pointer-list.h b/src/small-pointer-list.h
new file mode 100644
index 0000000..6291d9e
--- /dev/null
+++ b/src/small-pointer-list.h
@@ -0,0 +1,163 @@
+// Copyright 2011 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_SMALL_POINTER_LIST_H_
+#define V8_SMALL_POINTER_LIST_H_
+
+#include "checks.h"
+#include "v8globals.h"
+#include "zone.h"
+
+namespace v8 {
+namespace internal {
+
+// SmallPointerList is a list optimized for storing no or just a
+// single value. When more values are given it falls back to ZoneList.
+//
+// The interface tries to be as close to List from list.h as possible.
+template <typename T>
+class SmallPointerList {
+ public:
+ SmallPointerList() : data_(kEmptyTag) {}
+
+ bool is_empty() const { return length() == 0; }
+
+ int length() const {
+ if ((data_ & kTagMask) == kEmptyTag) return 0;
+ if ((data_ & kTagMask) == kSingletonTag) return 1;
+ return list()->length();
+ }
+
+ void Add(T* pointer) {
+ ASSERT(IsAligned(reinterpret_cast<intptr_t>(pointer), kPointerAlignment));
+ if ((data_ & kTagMask) == kEmptyTag) {
+ data_ = reinterpret_cast<intptr_t>(pointer) | kSingletonTag;
+ return;
+ }
+ if ((data_ & kTagMask) == kSingletonTag) {
+ PointerList* list = new PointerList(2);
+ list->Add(single_value());
+ list->Add(pointer);
+ ASSERT(IsAligned(reinterpret_cast<intptr_t>(list), kPointerAlignment));
+ data_ = reinterpret_cast<intptr_t>(list) | kListTag;
+ return;
+ }
+ list()->Add(pointer);
+ }
+
+ // Note: returns T* and not T*& (unlike List from list.h).
+ // This makes the implementation simpler and more const correct.
+ T* at(int i) const {
+ ASSERT((data_ & kTagMask) != kEmptyTag);
+ if ((data_ & kTagMask) == kSingletonTag) {
+ ASSERT(i == 0);
+ return single_value();
+ }
+ return list()->at(i);
+ }
+
+ // See the note above.
+ T* operator[](int i) const { return at(i); }
+
+ // Remove the given element from the list (if present).
+ void RemoveElement(T* pointer) {
+ if ((data_ & kTagMask) == kEmptyTag) return;
+ if ((data_ & kTagMask) == kSingletonTag) {
+ if (pointer == single_value()) {
+ data_ = kEmptyTag;
+ }
+ return;
+ }
+ list()->RemoveElement(pointer);
+ }
+
+ T* RemoveLast() {
+ ASSERT((data_ & kTagMask) != kEmptyTag);
+ if ((data_ & kTagMask) == kSingletonTag) {
+ T* result = single_value();
+ data_ = kEmptyTag;
+ return result;
+ }
+ return list()->RemoveLast();
+ }
+
+ void Rewind(int pos) {
+ if ((data_ & kTagMask) == kEmptyTag) {
+ ASSERT(pos == 0);
+ return;
+ }
+ if ((data_ & kTagMask) == kSingletonTag) {
+ ASSERT(pos == 0 || pos == 1);
+ if (pos == 0) {
+ data_ = kEmptyTag;
+ }
+ return;
+ }
+ list()->Rewind(pos);
+ }
+
+ int CountOccurrences(T* pointer, int start, int end) const {
+ if ((data_ & kTagMask) == kEmptyTag) return 0;
+ if ((data_ & kTagMask) == kSingletonTag) {
+ if (start == 0 && end >= 0) {
+ return (single_value() == pointer) ? 1 : 0;
+ }
+ return 0;
+ }
+ return list()->CountOccurrences(pointer, start, end);
+ }
+
+ private:
+ typedef ZoneList<T*> PointerList;
+
+ static const intptr_t kEmptyTag = 1;
+ static const intptr_t kSingletonTag = 0;
+ static const intptr_t kListTag = 2;
+ static const intptr_t kTagMask = 3;
+ static const intptr_t kValueMask = ~kTagMask;
+
+ STATIC_ASSERT(kTagMask + 1 <= kPointerAlignment);
+
+ T* single_value() const {
+ ASSERT((data_ & kTagMask) == kSingletonTag);
+ STATIC_ASSERT(kSingletonTag == 0);
+ return reinterpret_cast<T*>(data_);
+ }
+
+ PointerList* list() const {
+ ASSERT((data_ & kTagMask) == kListTag);
+ return reinterpret_cast<PointerList*>(data_ & kValueMask);
+ }
+
+ intptr_t data_;
+
+ DISALLOW_COPY_AND_ASSIGN(SmallPointerList);
+};
+
+} } // namespace v8::internal
+
+#endif // V8_SMALL_POINTER_LIST_H_