Address follow-up comments from aosp/3409718.

Bug: 297147201
Test: art/test/testrunner/testrunner.py --target --64
Test: ART_HEAP_POISONING=1 art/test/testrunner/testrunner.py --target --64
Change-Id: Ib37c7e0e446c80394bf058462b40f9feeaabc33e

1 files changed, 5 insertions, 7 deletions

diff --git a/compiler/optimizing/intrinsics_arm64.cc b/compiler/optimizing/intrinsics_arm64.cc
index 3eaaa6cb94..75607b77e0 100644
--- a/compiler/optimizing/intrinsics_arm64.cc
+++ b/compiler/optimizing/intrinsics_arm64.cc
@@ -6049,21 +6049,19 @@ void IntrinsicCodeGeneratorARM64::VisitMethodHandleInvokeExact(HInvoke* invoke)
     // If method is defined in the receiver's class, execute it as it is.
     __ Ldr(temp, MemOperand(method, ArtMethod::DeclaringClassOffset().Int32Value()));
     __ Ldr(receiver_class, HeapOperand(receiver.W(), mirror::Object::ClassOffset().Int32Value()));
+    codegen_->GetAssembler()->MaybeUnpoisonHeapReference(receiver_class.W());
+    // `receiver_class` is read w/o read barriers: false negatives go through virtual dispatch.
     __ Cmp(temp, receiver_class);
     __ B(eq, &execute_target_method);
 
     // MethodIndex is uint16_t.
     __ Ldrh(temp, MemOperand(method, ArtMethod::MethodIndexOffset().Int32Value()));
 
-    // Re-using method register for receiver class.
-    // /* HeapReference<Class> */ method = receiver->klass
-    __ Ldr(method.W(), HeapOperand(receiver.W(), mirror::Object::ClassOffset()));
-    codegen_->GetAssembler()->MaybeUnpoisonHeapReference(method.W());
-
+    // Re-using receiver class register to store vtable.
     constexpr uint32_t vtable_offset =
         mirror::Class::EmbeddedVTableOffset(art::PointerSize::k64).Int32Value();
-    __ Add(method, method, vtable_offset);
-    __ Ldr(method, MemOperand(method, temp, Extend::UXTW, 3u));
+    __ Add(receiver_class.X(), receiver_class.X(), vtable_offset);
+    __ Ldr(method, MemOperand(receiver_class.X(), temp, Extend::UXTW, 3u));
     __ B(&execute_target_method);
 
     __ Bind(&non_virtual_dispatch);