diff --git a/widget/cocoa/nsLookAndFeel.mm b/widget/cocoa/nsLookAndFeel.mm
index fd60089bf5..dd7de4c905 100644
--- a/widget/cocoa/nsLookAndFeel.mm
+++ b/widget/cocoa/nsLookAndFeel.mm
@@ -347,7 +347,7 @@ static nscolor GetColorFromNSColor(NSColor* aColor)
       aResult = 4;
       break;
     case eIntID_ScrollArrowStyle:
-#if(0)
+#ifdef __LP64__
       if (nsCocoaFeatures::OnLionOrLater()) {
         // OS X Lion's scrollbars have no arrows
         aResult = eScrollArrow_None;
@@ -374,18 +374,24 @@ static nscolor GetColorFromNSColor(NSColor* aColor)
       aResult = eScrollThumbStyle_Proportional;
       break;
     case eIntID_UseOverlayScrollbars:
+      aResult = 0;
+#ifdef __LP64__
       if (!mUseOverlayScrollbarsCached) {
         mUseOverlayScrollbars = SystemWantsOverlayScrollbars() ? 1 : 0;
         mUseOverlayScrollbarsCached = true;
       }
       aResult = mUseOverlayScrollbars;
+#endif
       break;
     case eIntID_AllowOverlayScrollbarsOverlap:
+      aResult = 0;
+#ifdef __LP64__
       if (!mAllowOverlayScrollbarsOverlapCached) {
         mAllowOverlayScrollbarsOverlap = AllowOverlayScrollbarsOverlap() ? 1 : 0;
         mAllowOverlayScrollbarsOverlapCached = true;
       }
       aResult = mAllowOverlayScrollbarsOverlap;
+#endif
       break;
     case eIntID_ScrollbarDisplayOnMouseMove:
       aResult = 0;
@@ -474,10 +480,12 @@ static nscolor GetColorFromNSColor(NSColor* aColor)
       break;
     case eIntID_SwipeAnimationEnabled:
       aResult = 0;
+#ifdef __LP64__
       if ([NSEvent respondsToSelector:@selector(
             isSwipeTrackingFromScrollEventsEnabled)]) {
         aResult = [NSEvent isSwipeTrackingFromScrollEventsEnabled] ? 1 : 0;
       }
+#endif
       break;
     case eIntID_ColorPickerAvailable:
       aResult = 1;
diff --git a/widget/nsXPLookAndFeel.cpp b/widget/nsXPLookAndFeel.cpp
index 7144e8e052..51d2485e11 100644
--- a/widget/nsXPLookAndFeel.cpp
+++ b/widget/nsXPLookAndFeel.cpp
@@ -821,7 +821,7 @@ nsXPLookAndFeel::GetColorImpl(ColorID aID, bool aUseStandinsForNativeColors,
 nsresult
 nsXPLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
 {
-  if (!sInitialized)
+  if (MOZ_UNLIKELY(!sInitialized))
     Init();
 
   // Set the default values for these prefs. but allow different platforms
@@ -845,7 +845,7 @@ nsXPLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
   }
 
   for (unsigned int i = 0; i < ArrayLength(sIntPrefs); ++i) {
-    if (sIntPrefs[i].isSet && (sIntPrefs[i].id == aID)) {
+    if (MOZ_UNLIKELY(sIntPrefs[i].isSet && (sIntPrefs[i].id == aID))) {
       aResult = sIntPrefs[i].intVar;
       return NS_OK;
     }
@@ -857,11 +857,11 @@ nsXPLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
 nsresult
 nsXPLookAndFeel::GetFloatImpl(FloatID aID, float &aResult)
 {
-  if (!sInitialized)
+  if (MOZ_UNLIKELY(!sInitialized))
     Init();
 
   for (unsigned int i = 0; i < ArrayLength(sFloatPrefs); ++i) {
-    if (sFloatPrefs[i].isSet && sFloatPrefs[i].id == aID) {
+    if (MOZ_UNLIKELY(sFloatPrefs[i].isSet && sFloatPrefs[i].id == aID)) {
       aResult = sFloatPrefs[i].floatVar;
       return NS_OK;
     }