[heap] Use template specialization for MarkBit accessors

BUG=chromium:694255
R=hpayer@chromium.org

Change-Id: Ie8d23ec88e9b8f97ac094630f4e46e9b31f93cc5
Reviewed-on: https://chromium-review.googlesource.com/452817Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43829}

src/heap/marking.h

@@ -39,47 +39,13 @@ class MarkBit {
   }
 
   template <AccessMode mode = NON_ATOMIC>
-  inline bool Set() {
-    if (mode == ATOMIC) {
-      base::Atomic32 old_value;
-      base::Atomic32 new_value;
-      do {
-        old_value = base::NoBarrier_Load(cell_);
-        if (old_value & mask_) return false;
-        new_value = old_value | mask_;
-      } while (base::Release_CompareAndSwap(cell_, old_value, new_value) !=
-               old_value);
-    } else {
-      *cell_ |= mask_;
-    }
-    return true;
-  }
+  inline bool Set();
 
   template <AccessMode mode = NON_ATOMIC>
-  inline bool Get() {
-    if (mode == ATOMIC) {
-      return (base::Acquire_Load(cell_) & mask_) != 0;
-    } else {
-      return (base::NoBarrier_Load(cell_) & mask_) != 0;
-    }
-  }
+  inline bool Get();
 
   template <AccessMode mode = NON_ATOMIC>
-  inline bool Clear() {
-    if (mode == ATOMIC) {
-      base::Atomic32 old_value;
-      base::Atomic32 new_value;
-      do {
-        old_value = base::NoBarrier_Load(cell_);
-        if (!(old_value & mask_)) return false;
-        new_value = old_value & ~mask_;
-      } while (base::Release_CompareAndSwap(cell_, old_value, new_value) !=
-               old_value);
-    } else {
-      *cell_ &= ~mask_;
-    }
-    return true;
-  }
+  inline bool Clear();
 
   base::Atomic32* cell_;
   base::Atomic32 mask_;
@@ -89,6 +55,54 @@ class MarkBit {
   friend class Marking;
 };
 
+template <>
+inline bool MarkBit::Set<MarkBit::NON_ATOMIC>() {
+  *cell_ |= mask_;
+  return true;
+}
+
+template <>
+inline bool MarkBit::Set<MarkBit::ATOMIC>() {
+  base::Atomic32 old_value;
+  base::Atomic32 new_value;
+  do {
+    old_value = base::NoBarrier_Load(cell_);
+    if (old_value & mask_) return false;
+    new_value = old_value | mask_;
+  } while (base::Release_CompareAndSwap(cell_, old_value, new_value) !=
+           old_value);
+  return true;
+}
+
+template <>
+inline bool MarkBit::Get<MarkBit::NON_ATOMIC>() {
+  return (base::NoBarrier_Load(cell_) & mask_) != 0;
+}
+
+template <>
+inline bool MarkBit::Get<MarkBit::ATOMIC>() {
+  return (base::Acquire_Load(cell_) & mask_) != 0;
+}
+
+template <>
+inline bool MarkBit::Clear<MarkBit::NON_ATOMIC>() {
+  *cell_ &= ~mask_;
+  return true;
+}
+
+template <>
+inline bool MarkBit::Clear<MarkBit::ATOMIC>() {
+  base::Atomic32 old_value;
+  base::Atomic32 new_value;
+  do {
+    old_value = base::NoBarrier_Load(cell_);
+    if (!(old_value & mask_)) return false;
+    new_value = old_value & ~mask_;
+  } while (base::Release_CompareAndSwap(cell_, old_value, new_value) !=
+           old_value);
+  return true;
+}
+
 // Bitmap is a sequence of cells each containing fixed number of bits.
 class Bitmap {
  public: