Small changes in ARM and x86-64 SystemArrayCopy intrinsics.

Have these intrinsics share a more uniform style with the
ARM64 SystemArrayCopy intrinsic.

Also make some changes/improvements in:
- art::IntrinsicOptimizations
- art::arm64::GenSystemArrayCopyAddresses

Change-Id: Ieeb224795229580f8e5f7219c586d04786d8c705
diff --git a/compiler/optimizing/intrinsics_arm.cc b/compiler/optimizing/intrinsics_arm.cc
index 4b94c94..86b7bc1 100644
--- a/compiler/optimizing/intrinsics_arm.cc
+++ b/compiler/optimizing/intrinsics_arm.cc
@@ -1394,15 +1394,13 @@
   SlowPathCode* slow_path = new (GetAllocator()) IntrinsicSlowPathARM(invoke);
   codegen_->AddSlowPath(slow_path);
 
-  Label ok;
+  Label conditions_on_positions_validated;
   SystemArrayCopyOptimizations optimizations(invoke);
 
-  if (!optimizations.GetDestinationIsSource()) {
-    if (!src_pos.IsConstant() || !dest_pos.IsConstant()) {
-      __ cmp(src, ShifterOperand(dest));
-    }
+  if (!optimizations.GetDestinationIsSource() &&
+      (!src_pos.IsConstant() || !dest_pos.IsConstant())) {
+    __ cmp(src, ShifterOperand(dest));
   }
-
   // If source and destination are the same, we go to slow path if we need to do
   // forward copying.
   if (src_pos.IsConstant()) {
@@ -1413,14 +1411,14 @@
              || (src_pos_constant >= dest_pos.GetConstant()->AsIntConstant()->GetValue()));
     } else {
       if (!optimizations.GetDestinationIsSource()) {
-        __ b(&ok, NE);
+        __ b(&conditions_on_positions_validated, NE);
       }
       __ cmp(dest_pos.AsRegister<Register>(), ShifterOperand(src_pos_constant));
       __ b(slow_path->GetEntryLabel(), GT);
     }
   } else {
     if (!optimizations.GetDestinationIsSource()) {
-      __ b(&ok, NE);
+      __ b(&conditions_on_positions_validated, NE);
     }
     if (dest_pos.IsConstant()) {
       int32_t dest_pos_constant = dest_pos.GetConstant()->AsIntConstant()->GetValue();
@@ -1431,7 +1429,7 @@
     __ b(slow_path->GetEntryLabel(), LT);
   }
 
-  __ Bind(&ok);
+  __ Bind(&conditions_on_positions_validated);
 
   if (!optimizations.GetSourceIsNotNull()) {
     // Bail out if the source is null.
@@ -1482,7 +1480,7 @@
     bool did_unpoison = false;
     if (!optimizations.GetDestinationIsNonPrimitiveArray() ||
         !optimizations.GetSourceIsNonPrimitiveArray()) {
-      // One or two of the references need to be unpoisoned. Unpoisoned them
+      // One or two of the references need to be unpoisoned. Unpoison them
       // both to make the identity check valid.
       __ MaybeUnpoisonHeapReference(temp1);
       __ MaybeUnpoisonHeapReference(temp2);
@@ -1491,6 +1489,7 @@
 
     if (!optimizations.GetDestinationIsNonPrimitiveArray()) {
       // Bail out if the destination is not a non primitive array.
+      // /* HeapReference<Class> */ temp3 = temp1->component_type_
       __ LoadFromOffset(kLoadWord, temp3, temp1, component_offset);
       __ CompareAndBranchIfZero(temp3, slow_path->GetEntryLabel());
       __ MaybeUnpoisonHeapReference(temp3);
@@ -1501,7 +1500,7 @@
 
     if (!optimizations.GetSourceIsNonPrimitiveArray()) {
       // Bail out if the source is not a non primitive array.
-      // Bail out if the destination is not a non primitive array.
+      // /* HeapReference<Class> */ temp3 = temp2->component_type_
       __ LoadFromOffset(kLoadWord, temp3, temp2, component_offset);
       __ CompareAndBranchIfZero(temp3, slow_path->GetEntryLabel());
       __ MaybeUnpoisonHeapReference(temp3);
@@ -1518,8 +1517,10 @@
       if (!did_unpoison) {
         __ MaybeUnpoisonHeapReference(temp1);
       }
+      // /* HeapReference<Class> */ temp1 = temp1->component_type_
       __ LoadFromOffset(kLoadWord, temp1, temp1, component_offset);
       __ MaybeUnpoisonHeapReference(temp1);
+      // /* HeapReference<Class> */ temp1 = temp1->super_class_
       __ LoadFromOffset(kLoadWord, temp1, temp1, super_offset);
       // No need to unpoison the result, we're comparing against null.
       __ CompareAndBranchIfNonZero(temp1, slow_path->GetEntryLabel());
@@ -1530,8 +1531,10 @@
   } else if (!optimizations.GetSourceIsNonPrimitiveArray()) {
     DCHECK(optimizations.GetDestinationIsNonPrimitiveArray());
     // Bail out if the source is not a non primitive array.
+    // /* HeapReference<Class> */ temp1 = src->klass_
     __ LoadFromOffset(kLoadWord, temp1, src, class_offset);
     __ MaybeUnpoisonHeapReference(temp1);
+    // /* HeapReference<Class> */ temp3 = temp1->component_type_
     __ LoadFromOffset(kLoadWord, temp3, temp1, component_offset);
     __ CompareAndBranchIfZero(temp3, slow_path->GetEntryLabel());
     __ MaybeUnpoisonHeapReference(temp3);
@@ -1585,7 +1588,7 @@
                        temp2,
                        dest,
                        Register(kNoRegister),
-                       /* can_be_null */ false);
+                       /* value_can_be_null */ false);
 
   __ Bind(slow_path->GetExitLabel());
 }