Revert r11835 'Unify promotion and allocation limit computation' due to V8...

Revert r11835 'Unify promotion and allocation limit computation' due to V8 Splay performance regression on Mac.

R=mstarzinger@chromium.org
BUG=134183

Review URL: https://chromiumcodereview.appspot.com/10664013

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11916 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -118,8 +118,8 @@ Heap::Heap()
       debug_utils_(NULL),
 #endif  // DEBUG
       new_space_high_promotion_mode_active_(false),
-      old_gen_promotion_limit_(kMinPromotionLimit),
-      old_gen_allocation_limit_(kMinAllocationLimit),
+      old_gen_promotion_limit_(kMinimumPromotionLimit),
+      old_gen_allocation_limit_(kMinimumAllocationLimit),
       old_gen_limit_factor_(1),
       size_of_old_gen_at_last_old_space_gc_(0),
       external_allocation_limit_(0),
@@ -829,9 +829,9 @@ bool Heap::PerformGarbageCollection(GarbageCollector collector,
     }
 
     old_gen_promotion_limit_ =
-        OldGenLimit(size_of_old_gen_at_last_old_space_gc_, kMinPromotionLimit);
+        OldGenPromotionLimit(size_of_old_gen_at_last_old_space_gc_);
     old_gen_allocation_limit_ =
-        OldGenLimit(size_of_old_gen_at_last_old_space_gc_, kMinAllocationLimit);
+        OldGenAllocationLimit(size_of_old_gen_at_last_old_space_gc_);
 
     old_gen_exhausted_ = false;
   } else {

src/heap.h

@@ -1359,13 +1359,24 @@ class Heap {
     return max_old_generation_size_ - PromotedTotalSize();
   }
 
-  static const intptr_t kMinPromotionLimit = 5 * Page::kPageSize;
-  static const intptr_t kMinAllocationLimit =
+  static const intptr_t kMinimumPromotionLimit = 5 * Page::kPageSize;
+  static const intptr_t kMinimumAllocationLimit =
       8 * (Page::kPageSize > MB ? Page::kPageSize : MB);
 
-  intptr_t OldGenLimit(intptr_t old_gen_size, intptr_t min_limit) {
+  intptr_t OldGenPromotionLimit(intptr_t old_gen_size) {
+    const int divisor = FLAG_stress_compaction ? 10 : 3;
+    intptr_t limit =
+        Max(old_gen_size + old_gen_size / divisor, kMinimumPromotionLimit);
+    limit += new_space_.Capacity();
+    limit *= old_gen_limit_factor_;
+    intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;
+    return Min(limit, halfway_to_the_max);
+  }
+
+  intptr_t OldGenAllocationLimit(intptr_t old_gen_size) {
     const int divisor = FLAG_stress_compaction ? 8 : 2;
-    intptr_t limit = Max(old_gen_size + old_gen_size / divisor, min_limit);
+    intptr_t limit =
+        Max(old_gen_size + old_gen_size / divisor, kMinimumAllocationLimit);
     limit += new_space_.Capacity();
     limit *= old_gen_limit_factor_;
     intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;