Changeset 60323 in webkit for trunk/JavaScriptCore/runtime

Timestamp:

May 27, 2010, 2:45:10 PM (15 years ago)

Author:

[email protected]

Message:

2010-05-27 Nathan Lawrence <​[email protected]>

Reviewed by Geoffrey Garen.

Search for the new allocation one word at a time. Improves
performance on SunSpider by approximately 1%.
​http://bugs.webkit.org/show_bug.cgi?id=39758

• runtime/Collector.cpp: (JSC::Heap::allocate):
• runtime/Collector.h: (JSC::CollectorBitmap::advanceToNextPossibleFreeCell):

Location:

trunk/JavaScriptCore/runtime

Files:

• Collector.cpp (modified) (1 diff)
• Collector.h (modified) (1 diff)

trunk/JavaScriptCore/runtime/Collector.cpp

@@ -395 +395 @@
                 return cell;
             }
-        } while (++m_heap.nextCell != HeapConstants::cellsPerBlock);
+            block->marked.advanceToNextPossibleFreeCell(m_heap.nextCell);
+        } while (m_heap.nextCell != HeapConstants::cellsPerBlock);
         m_heap.nextCell = 0;
     } while (++m_heap.nextBlock != m_heap.usedBlocks);

trunk/JavaScriptCore/runtime/Collector.h

@@ -221 +221 @@
         void clear(size_t n) { bits[n >> 5] &= ~(1 << (n & 0x1F)); } 
         void clearAll() { memset(bits, 0, sizeof(bits)); }
+        ALWAYS_INLINE void advanceToNextPossibleFreeCell(size_t& startCell)
+        {
+            if (!~bits[startCell >> 5])
+                startCell = (startCell & (~0x1F)) + 32;
+            else
+                ++startCell;
+        }
         size_t count(size_t startCell = 0)
         {