Fix a bug in DeadPhiHandling around conflicting phis.
Change-Id: I44ec40f71a7e05eb4295bea55f6045cb86017329
diff --git a/compiler/optimizing/ssa_builder.cc b/compiler/optimizing/ssa_builder.cc
index fb11d76..40c75af 100644
--- a/compiler/optimizing/ssa_builder.cc
+++ b/compiler/optimizing/ssa_builder.cc
@@ -56,6 +56,24 @@
DISALLOW_COPY_AND_ASSIGN(DeadPhiHandling);
};
+static bool HasConflictingEquivalent(HPhi* phi) {
+ if (phi->GetNext() == nullptr) {
+ return false;
+ }
+ HPhi* next = phi->GetNext()->AsPhi();
+ if (next->GetRegNumber() == phi->GetRegNumber()) {
+ if (next->GetType() == Primitive::kPrimVoid) {
+ // We only get a void type for an equivalent phi we processed and found out
+ // it was conflicting.
+ return true;
+ } else {
+ // Go to the next phi, in case it is also an equivalent.
+ return HasConflictingEquivalent(next);
+ }
+ }
+ return false;
+}
+
bool DeadPhiHandling::UpdateType(HPhi* phi) {
if (phi->IsDead()) {
// Phi was rendered dead while waiting in the worklist because it was replaced
@@ -87,21 +105,26 @@
if (new_type == Primitive::kPrimVoid) {
new_type = input_type;
} else if (new_type == Primitive::kPrimNot && input_type == Primitive::kPrimInt) {
+ if (input->IsPhi() && HasConflictingEquivalent(input->AsPhi())) {
+ // If we already asked for an equivalent of the input phi, but that equivalent
+ // ended up conflicting, make this phi conflicting too.
+ conflict = true;
+ break;
+ }
HInstruction* equivalent = SsaBuilder::GetReferenceTypeEquivalent(input);
if (equivalent == nullptr) {
conflict = true;
break;
- } else {
- phi->ReplaceInput(equivalent, i);
- if (equivalent->IsPhi()) {
- DCHECK_EQ(equivalent->GetType(), Primitive::kPrimNot);
- // We created a new phi, but that phi has the same inputs as the old phi. We
- // add it to the worklist to ensure its inputs can also be converted to reference.
- // If not, it will remain dead, and the algorithm will make the current phi dead
- // as well.
- equivalent->AsPhi()->SetLive();
- AddToWorklist(equivalent->AsPhi());
- }
+ }
+ phi->ReplaceInput(equivalent, i);
+ if (equivalent->IsPhi()) {
+ DCHECK_EQ(equivalent->GetType(), Primitive::kPrimNot);
+ // We created a new phi, but that phi has the same inputs as the old phi. We
+ // add it to the worklist to ensure its inputs can also be converted to reference.
+ // If not, it will remain dead, and the algorithm will make the current phi dead
+ // as well.
+ equivalent->AsPhi()->SetLive();
+ AddToWorklist(equivalent->AsPhi());
}
} else if (new_type == Primitive::kPrimInt && input_type == Primitive::kPrimNot) {
new_type = Primitive::kPrimNot;