[heap] Remove separate constant for newspace page allocatable size

src/heap/spaces.h

 // Copyright 2011 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_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include "src/allocation.h"
 #include "src/atomic-utils.h"
 #include "src/base/atomicops.h"
@@ skipping 399 matching lines @@
   // The start offset of the object area in a page. Aligned to both maps and
   // code alignment to be suitable for both.  Also aligned to 32 words because
   // the marking bitmap is arranged in 32 bit chunks.
   static const int kObjectStartAlignment = 32 * kPointerSize;
   static const int kObjectStartOffset =
       kBodyOffset - 1 +
       (kObjectStartAlignment - (kBodyOffset - 1) % kObjectStartAlignment);
 
   static const int kFlagsOffset = kPointerSize;
 
+  // Page size in bytes.  This must be a multiple of the OS page size.
+  static const int kPageSize = 1 << kPageSizeBits;
+  static const intptr_t kPageAlignmentMask = (1 << kPageSizeBits) - 1;
+
+  static const int kAllocatableMemory = kPageSize - kObjectStartOffset;
+
   static inline void IncrementLiveBytesFromMutator(HeapObject* object, int by);
   static inline void IncrementLiveBytesFromGC(HeapObject* object, int by);
 
   // Only works if the pointer is in the first kPageSize of the MemoryChunk.
   static MemoryChunk* FromAddress(Address a) {
     return reinterpret_cast<MemoryChunk*>(OffsetFrom(a) & ~kAlignmentMask);
   }
 
   static inline MemoryChunk* FromAnyPointerAddress(Heap* heap, Address addr);
 
@@ skipping 341 matching lines @@
   }
 
   // Returns the address for a given offset to the this page.
   Address OffsetToAddress(int offset) {
     DCHECK_PAGE_OFFSET(offset);
     return address() + offset;
   }
 
   // ---------------------------------------------------------------------
 
-  // Page size in bytes.  This must be a multiple of the OS page size.
-  static const int kPageSize = 1 << kPageSizeBits;
-
   // Maximum object size that gets allocated into regular pages. Objects larger
   // than that size are allocated in large object space and are never moved in
   // memory. This also applies to new space allocation, since objects are never
   // migrated from new space to large object space. Takes double alignment into
   // account.
   // TODO(hpayer): This limit should be way smaller but we currently have
   // short living objects >256K.
   static const int kMaxRegularHeapObjectSize = 600 * KB;
 
-  static const int kAllocatableMemory = kPageSize - kObjectStartOffset;
-
-  // Page size mask.
-  static const intptr_t kPageAlignmentMask = (1 << kPageSizeBits) - 1;
-
   inline void ClearGCFields();
 
   static inline Page* Initialize(Heap* heap, MemoryChunk* chunk,
                                  Executability executable, PagedSpace* owner);
 
   void InitializeAsAnchor(PagedSpace* owner);
 
   // WaitUntilSweepingCompleted only works when concurrent sweeping is in
   // progress. In particular, when we know that right before this call a
   // sweeper thread was sweeping this page.
@@ skipping 1383 matching lines @@
  private:
   const char* name_;
 };
 
 
 enum SemiSpaceId { kFromSpace = 0, kToSpace = 1 };
 
 
 class NewSpacePage : public MemoryChunk {
  public:
-  // GC related flags copied from from-space to to-space when
-  // flipping semispaces.
-  static const intptr_t kCopyOnFlipFlagsMask =
-      (1 << MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING) |
-      (1 << MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
-
-  static const int kAreaSize = Page::kAllocatableMemory;

[Michael Lippautz, 2016/03/17 10:13:43]

Now available on MemoryChunk since the allocatable area is the same.

-
-  inline NewSpacePage* next_page() {
-    return static_cast<NewSpacePage*>(next_chunk());
-  }
-
-  inline void set_next_page(NewSpacePage* page) { set_next_chunk(page); }
-
-  inline NewSpacePage* prev_page() {
-    return static_cast<NewSpacePage*>(prev_chunk());
-  }
-
-  inline void set_prev_page(NewSpacePage* page) { set_prev_chunk(page); }
-
-  SemiSpace* semi_space() { return reinterpret_cast<SemiSpace*>(owner()); }
-
-  bool is_anchor() { return !this->InNewSpace(); }
-
   static bool IsAtStart(Address addr) {
     return (reinterpret_cast<intptr_t>(addr) & Page::kPageAlignmentMask) ==
            kObjectStartOffset;
   }
 
   static bool IsAtEnd(Address addr) {
     return (reinterpret_cast<intptr_t>(addr) & Page::kPageAlignmentMask) == 0;
   }
 
-  Address address() { return reinterpret_cast<Address>(this); }

[Michael Lippautz, 2016/03/17 10:13:43]

dead code

-
   // Finds the NewSpacePage containing the given address.
   static inline NewSpacePage* FromAddress(Address address_in_page) {
     Address page_start =
         reinterpret_cast<Address>(reinterpret_cast<uintptr_t>(address_in_page) &
                                   ~Page::kPageAlignmentMask);
     NewSpacePage* page = reinterpret_cast<NewSpacePage*>(page_start);
     return page;
   }
 
   // Find the page for a limit address. A limit address is either an address
   // inside a page, or the address right after the last byte of a page.
   static inline NewSpacePage* FromLimit(Address address_limit) {
     return NewSpacePage::FromAddress(address_limit - 1);
   }
 
   // Checks if address1 and address2 are on the same new space page.
   static inline bool OnSamePage(Address address1, Address address2) {
     return NewSpacePage::FromAddress(address1) ==
            NewSpacePage::FromAddress(address2);
   }
 
+  inline NewSpacePage* next_page() {
+    return static_cast<NewSpacePage*>(next_chunk());
+  }
+
+  inline void set_next_page(NewSpacePage* page) { set_next_chunk(page); }
+
+  inline NewSpacePage* prev_page() {
+    return static_cast<NewSpacePage*>(prev_chunk());
+  }
+
+  inline void set_prev_page(NewSpacePage* page) { set_prev_chunk(page); }
+
+  SemiSpace* semi_space() { return reinterpret_cast<SemiSpace*>(owner()); }
+
+  bool is_anchor() { return !this->InNewSpace(); }
+
  private:
+  // GC related flags copied from from-space to to-space when
+  // flipping semispaces.
+  static const intptr_t kCopyOnFlipFlagsMask =
+      (1 << MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING) |
+      (1 << MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
+
   // Create a NewSpacePage object that is only used as anchor
   // for the doubly-linked list of real pages.
   explicit NewSpacePage(SemiSpace* owner) { InitializeAsAnchor(owner); }
 
   static NewSpacePage* Initialize(Heap* heap, Address start,
                                   SemiSpace* semi_space);
 
   // Intialize a fake NewSpacePage used as sentinel at the ends
   // of a doubly-linked list of real NewSpacePages.
   // Only uses the prev/next links, and sets flags to not be in new-space.
@@ skipping 256 matching lines @@
 
   // Grow the capacity of the semispaces.  Assumes that they are not at
   // their maximum capacity.
   void Grow();
 
   // Shrink the capacity of the semispaces.
   void Shrink();
 
   // Return the allocated bytes in the active semispace.
   intptr_t Size() override {
-    return pages_used_ * NewSpacePage::kAreaSize +
+    return pages_used_ * NewSpacePage::kAllocatableMemory +
            static_cast<int>(top() - to_space_.page_low());
   }
 
   // The same, but returning an int.  We have to have the one that returns
   // intptr_t because it is inherited, but if we know we are dealing with the
   // new space, which can't get as big as the other spaces then this is useful:
   int SizeAsInt() { return static_cast<int>(Size()); }
 
   // Return the allocatable capacity of a semispace.
   intptr_t Capacity() {
     SLOW_DCHECK(to_space_.current_capacity() == from_space_.current_capacity());
     return (to_space_.current_capacity() / Page::kPageSize) *
-           NewSpacePage::kAreaSize;
+           NewSpacePage::kAllocatableMemory;
   }
 
   // Return the current size of a semispace, allocatable and non-allocatable
   // memory.
   intptr_t TotalCapacity() {
     DCHECK(to_space_.current_capacity() == from_space_.current_capacity());
     return to_space_.current_capacity();
   }
 
   // Committed memory for NewSpace is the committed memory of both semi-spaces
@@ skipping 469 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_