5 files changed, 20 insertions, 33 deletions
diff --git a/compiler/optimizing/dead_code_elimination.cc b/compiler/optimizing/dead_code_elimination.cc
index 8e6b6db236..5a7b83603f 100644
--- a/compiler/optimizing/dead_code_elimination.cc
+++ b/compiler/optimizing/dead_code_elimination.cc
@@ -312,9 +312,7 @@ bool HDeadCodeElimination::SimplifyAlwaysThrows() {
 
   // We need to re-analyze the graph in order to run DCE afterwards.
   if (rerun_dominance_and_loop_analysis) {
-    graph_->ClearLoopInformation();
-    graph_->ClearDominanceInformation();
-    graph_->BuildDominatorTree();
+    graph_->RecomputeDominatorTree();
     return true;
   }
   return false;
@@ -438,9 +436,7 @@ bool HDeadCodeElimination::SimplifyIfs() {
   // We need to re-analyze the graph in order to run DCE afterwards.
   if (simplified_one_or_more_ifs) {
     if (rerun_dominance_and_loop_analysis) {
-      graph_->ClearLoopInformation();
-      graph_->ClearDominanceInformation();
-      graph_->BuildDominatorTree();
+      graph_->RecomputeDominatorTree();
     } else {
       graph_->ClearDominanceInformation();
       // We have introduced critical edges, remove them.
@@ -808,9 +804,7 @@ bool HDeadCodeElimination::RemoveDeadBlocks(bool force_recomputation,
   // dominator tree and try block membership.
   if (removed_one_or_more_blocks || force_recomputation) {
     if (rerun_dominance_and_loop_analysis || force_loop_recomputation) {
-      graph_->ClearLoopInformation();
-      graph_->ClearDominanceInformation();
-      graph_->BuildDominatorTree();
+      graph_->RecomputeDominatorTree();
     } else {
       graph_->ClearDominanceInformation();
       graph_->ComputeDominanceInformation();
diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index 58fdd1cd05..36c3770c42 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -1364,7 +1364,9 @@ class LSEVisitor final : private HGraphDelegateVisitor {
   }
 
   bool ShouldPerformPartialLSE() const {
-    return perform_partial_lse_ && !GetGraph()->IsCompilingOsr();
+    return perform_partial_lse_ &&
+           !GetGraph()->IsCompilingOsr() &&
+           !GetGraph()->HasIrreducibleLoops();
   }
 
   bool perform_partial_lse_;
@@ -3072,10 +3074,8 @@ class PartialLoadStoreEliminationHelper {
                                        Handle<mirror::DexCache>(),
                                        /* is_first_run= */ false);
     rtp_fixup.Visit(ArrayRef<HInstruction* const>(new_ref_phis_));
-    GetGraph()->ClearLoopInformation();
-    GetGraph()->ClearDominanceInformation();
     GetGraph()->ClearReachabilityInformation();
-    GetGraph()->BuildDominatorTree();
+    GetGraph()->RecomputeDominatorTree();
     GetGraph()->ComputeReachabilityInformation();
   }
 
diff --git a/compiler/optimizing/load_store_elimination_test.cc b/compiler/optimizing/load_store_elimination_test.cc
index d3cf8bfa2a..eb0711343d 100644
--- a/compiler/optimizing/load_store_elimination_test.cc
+++ b/compiler/optimizing/load_store_elimination_test.cc
@@ -8111,21 +8111,10 @@ TEST_F(LoadStoreEliminationTest, PartialIrreducibleLoop) {
   EXPECT_TRUE(loop_header->IsLoopHeader());
   EXPECT_TRUE(loop_header->GetLoopInformation()->IsIrreducible());
 
+  // Partial LSE cannot run with irreducible loops.
   EXPECT_INS_RETAINED(left_set);
-  EXPECT_INS_REMOVED(write_start);
-  EXPECT_INS_REMOVED(read_end);
-
-  HPredicatedInstanceFieldGet* pred_get =
-      FindSingleInstruction<HPredicatedInstanceFieldGet>(graph_, breturn);
-  ASSERT_NE(pred_get, nullptr);
-  ASSERT_TRUE(pred_get->GetDefaultValue()->IsPhi()) << pred_get->DumpWithArgs();
-  EXPECT_INS_EQ(pred_get->GetDefaultValue()->InputAt(0), c11);
-  EXPECT_INS_EQ(pred_get->GetDefaultValue()->InputAt(1), graph_->GetIntConstant(0));
-  ASSERT_TRUE(pred_get->GetTarget()->IsPhi()) << pred_get->DumpWithArgs();
-  EXPECT_INS_EQ(pred_get->GetTarget()->InputAt(0), graph_->GetNullConstant());
-  HNewInstance* mat = FindSingleInstruction<HNewInstance>(graph_, right->GetSinglePredecessor());
-  ASSERT_NE(mat, nullptr);
-  EXPECT_INS_EQ(pred_get->GetTarget()->InputAt(1), mat);
+  EXPECT_INS_RETAINED(write_start);
+  EXPECT_INS_RETAINED(read_end);
 }
 
 enum class UsesOrder { kDefaultOrder, kReverseOrder };
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 5795ea7ca9..53ed49a307 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -255,6 +255,14 @@ GraphAnalysisResult HGraph::BuildDominatorTree() {
   return kAnalysisSuccess;
 }
 
+GraphAnalysisResult HGraph::RecomputeDominatorTree() {
+  DCHECK(!HasIrreducibleLoops()) << "Recomputing loop information in graphs with irreducible loops "
+                                 << "is unsupported, as it could lead to loop header changes";
+  ClearLoopInformation();
+  ClearDominanceInformation();
+  return BuildDominatorTree();
+}
+
 void HGraph::ClearDominanceInformation() {
   for (HBasicBlock* block : GetActiveBlocks()) {
     block->ClearDominanceInformation();
@@ -3001,12 +3009,7 @@ HInstruction* HGraph::InlineInto(HGraph* outer_graph, HInvoke* invoke) {
       }
     }
     if (rerun_loop_analysis) {
-      DCHECK(!outer_graph->HasIrreducibleLoops())
-          << "Recomputing loop information in graphs with irreducible loops "
-          << "is unsupported, as it could lead to loop header changes";
-      outer_graph->ClearLoopInformation();
-      outer_graph->ClearDominanceInformation();
-      outer_graph->BuildDominatorTree();
+      outer_graph->RecomputeDominatorTree();
     } else if (rerun_dominance) {
       outer_graph->ClearDominanceInformation();
       outer_graph->ComputeDominanceInformation();
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 9cf52183b8..3613b9519b 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -467,6 +467,7 @@ class HGraph : public ArenaObject<kArenaAllocGraph> {
   void ClearLoopInformation();
   void FindBackEdges(ArenaBitVector* visited);
   GraphAnalysisResult BuildDominatorTree();
+  GraphAnalysisResult RecomputeDominatorTree();
   void SimplifyCFG();
   void SimplifyCatchBlocks();