Check that the String class is not movable in String.equals intrinsics.
Test: art/test.py
Bug: 68181300
Bug: 67628039
Change-Id: I66afa3ea010f758125f8aec79509f0255cb5ea03
diff --git a/compiler/optimizing/intrinsics_mips.cc b/compiler/optimizing/intrinsics_mips.cc
index 6f7f5e4..2ca12b6 100644
--- a/compiler/optimizing/intrinsics_mips.cc
+++ b/compiler/optimizing/intrinsics_mips.cc
@@ -1575,8 +1575,16 @@
// All string objects must have the same type since String cannot be subclassed.
// Receiver must be a string object, so its class field is equal to all strings' class fields.
// If the argument is a string object, its class field must be equal to receiver's class field.
+ //
+ // As the String class is expected to be non-movable, we can read the class
+ // field from String.equals' arguments without read barriers.
+ AssertNonMovableStringClass();
+ // /* HeapReference<Class> */ temp1 = str->klass_
__ Lw(temp1, str, class_offset);
+ // /* HeapReference<Class> */ temp2 = arg->klass_
__ Lw(temp2, arg, class_offset);
+ // Also, because we use the previously loaded class references only in the
+ // following comparison, we don't need to unpoison them.
__ Bne(temp1, temp2, &return_false);
}