Merge "Prevent loop optimization in debuggable mode."

2 files changed, 16 insertions, 0 deletions

diff --git a/compiler/optimizing/loop_optimization.cc b/compiler/optimizing/loop_optimization.cc
index d39bc16ed2..32f40024d3 100644
--- a/compiler/optimizing/loop_optimization.cc
+++ b/compiler/optimizing/loop_optimization.cc
@@ -1550,6 +1550,12 @@ uint32_t HLoopOptimization::GetUnrollingFactor(HBasicBlock* block, int64_t trip_
 //
 
 bool HLoopOptimization::TrySetPhiInduction(HPhi* phi, bool restrict_uses) {
+  // Special case Phis that have equivalent in a debuggable setup. Our graph checker isn't
+  // smart enough to follow strongly connected components (and it's probably not worth
+  // it to make it so). See b/33775412.
+  if (graph_->IsDebuggable() && phi->HasEquivalentPhi()) {
+    return false;
+  }
   DCHECK(iset_->empty());
   ArenaSet<HInstruction*>* set = induction_range_.LookupCycle(phi);
   if (set != nullptr) {
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index ffa16dd787..b21c4a5aa7 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -2612,6 +2612,16 @@ class HPhi FINAL : public HVariableInputSizeInstruction {
         && other->AsPhi()->GetRegNumber() == GetRegNumber();
   }
 
+  bool HasEquivalentPhi() const {
+    if (GetPrevious() != nullptr && GetPrevious()->AsPhi()->GetRegNumber() == GetRegNumber()) {
+      return true;
+    }
+    if (GetNext() != nullptr && GetNext()->AsPhi()->GetRegNumber() == GetRegNumber()) {
+      return true;
+    }
+    return false;
+  }
+
   // Returns the next equivalent phi (starting from the current one) or null if there is none.
   // An equivalent phi is a phi having the same dex register and type.
   // It assumes that phis with the same dex register are adjacent.