Do not remove loads/store with unresolved accesses.

Due to AOT and compiling classes that are not ready yet
(eg missing a super class), we need to be conservative when
accessing fields and can end up in a situation where the same
field can be resolved and unresolved within the same method
(because of inlining). Therefore, disable removing loads and
stores in a method when there are unresolved accesses.

bug:29433999

(cherry picked from commit b93a16517dce12b83e9d5d3b599446e25fcc157a)

Change-Id: I8fcfb52c584222474a8220eb16c6581350b702e0

1 files changed, 10 insertions, 0 deletions

diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index b4d93add9c..874f3be9b8 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -65,6 +65,16 @@ class ReferenceInfo : public ArenaObject<kArenaAllocMisc> {
         is_singleton_and_not_returned_ = false;
         return;
       }
+      if ((user->IsUnresolvedInstanceFieldGet() && (reference_ == user->InputAt(0))) ||
+          (user->IsUnresolvedInstanceFieldSet() && (reference_ == user->InputAt(0)))) {
+        // The field is accessed in an unresolved way. We mark the object as a singleton to
+        // disable load/store optimizations on it.
+        // Note that we could optimize this case and still perform some optimizations until
+        // we hit the unresolved access, but disabling is the simplest.
+        is_singleton_ = false;
+        is_singleton_and_not_returned_ = false;
+        return;
+      }
       if (user->IsReturn()) {
         is_singleton_and_not_returned_ = false;
       }