Ensure the graph is correctly typed.
We used to be forgiving because of HIntConstant(0) also being
used for null. We now create a special HNullConstant for such uses.
Also, we need to run the dead phi elimination twice during ssa
building to ensure the correctness.
Change-Id: If479efa3680d3358800aebb1cca692fa2d94f6e5
diff --git a/compiler/optimizing/reference_type_propagation.cc b/compiler/optimizing/reference_type_propagation.cc
index 24e6837..4f17b6f 100644
--- a/compiler/optimizing/reference_type_propagation.cc
+++ b/compiler/optimizing/reference_type_propagation.cc
@@ -18,10 +18,6 @@
namespace art {
-// TODO: Only do the analysis on reference types. We currently have to handle
-// the `null` constant, that is represented as a `HIntConstant` and therefore
-// has the Primitive::kPrimInt type.
-
void ReferenceTypePropagation::Run() {
// Compute null status for instructions.
@@ -54,8 +50,10 @@
// Set the initial type for the phi. Use the non back edge input for reaching
// a fixed point faster.
HPhi* phi = it.Current()->AsPhi();
- AddToWorklist(phi);
- phi->SetCanBeNull(phi->InputAt(0)->CanBeNull());
+ if (phi->GetType() == Primitive::kPrimNot) {
+ AddToWorklist(phi);
+ phi->SetCanBeNull(phi->InputAt(0)->CanBeNull());
+ }
}
} else {
for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
@@ -64,7 +62,10 @@
// doing a reverse post-order visit, therefore either the phi users are
// non-loop phi and will be visited later in the visit, or are loop-phis,
// and they are already in the work list.
- UpdateNullability(it.Current()->AsPhi());
+ HPhi* phi = it.Current()->AsPhi();
+ if (phi->GetType() == Primitive::kPrimNot) {
+ UpdateNullability(phi);
+ }
}
}
}
@@ -79,6 +80,7 @@
}
void ReferenceTypePropagation::AddToWorklist(HPhi* instruction) {
+ DCHECK_EQ(instruction->GetType(), Primitive::kPrimNot);
worklist_.Add(instruction);
}