Don't compile OSR methods that have phi equivalents at loop entry.
We currently don't handle this in the stack map, where we only encode
one stack slot for a dex register.
Bug: 136698025
Test: 721-osr
Change-Id: Ib395ed1165387ad5446a463c307cc0a45e365885
diff --git a/compiler/optimizing/ssa_builder.cc b/compiler/optimizing/ssa_builder.cc
index 0d0e1ec..a5e8ff6 100644
--- a/compiler/optimizing/ssa_builder.cc
+++ b/compiler/optimizing/ssa_builder.cc
@@ -496,6 +496,22 @@
}
}
+static bool HasPhiEquivalentAtLoopEntry(HGraph* graph) {
+ // Phi equivalents for a dex register do not work with OSR, as the phis will
+ // receive two different stack slots but only one is recorded in the stack
+ // map.
+ for (HBasicBlock* block : graph->GetReversePostOrder()) {
+ if (block->IsLoopHeader()) {
+ for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
+ if (it.Current()->AsPhi()->HasEquivalentPhi()) {
+ return true;
+ }
+ }
+ }
+ }
+ return false;
+}
+
GraphAnalysisResult SsaBuilder::BuildSsa() {
DCHECK(!graph_->IsInSsaForm());
@@ -574,6 +590,10 @@
// other optimizations.
RemoveRedundantUninitializedStrings();
+ if (graph_->IsCompilingOsr() && HasPhiEquivalentAtLoopEntry(graph_)) {
+ return kAnalysisFailPhiEquivalentInOsr;
+ }
+
graph_->SetInSsaForm();
return kAnalysisSuccess;
}