Optimizing: Do not re-record standby checks for dynamic BCE.

Adding the checks to the standby vector invalidates the
vector storage used by range-based loop in the
BCEVisitor::Finish() as exposed by valgrind in image_test.

Bug: 27597089
Change-Id: Ib0f0e8cdfdb7211a64a26836e085cb99fb2ce8b8

1 files changed, 6 insertions, 1 deletions

diff --git a/compiler/optimizing/bounds_check_elimination.cc b/compiler/optimizing/bounds_check_elimination.cc
index f2929bcc18..4e0c38c049 100644
--- a/compiler/optimizing/bounds_check_elimination.cc
+++ b/compiler/optimizing/bounds_check_elimination.cc
@@ -535,6 +535,7 @@ class BCEVisitor : public HGraphVisitor {
             graph->GetArena()->Adapter(kArenaAllocBoundsCheckElimination)),
         dynamic_bce_standby_(
             graph->GetArena()->Adapter(kArenaAllocBoundsCheckElimination)),
+        record_dynamic_bce_standby_(true),
         early_exit_loop_(
             std::less<uint32_t>(),
             graph->GetArena()->Adapter(kArenaAllocBoundsCheckElimination)),
@@ -556,6 +557,7 @@ class BCEVisitor : public HGraphVisitor {
 
   void Finish() {
     // Retry dynamic bce candidates on standby that are still in the graph.
+    record_dynamic_bce_standby_ = false;
     for (HBoundsCheck* bounds_check : dynamic_bce_standby_) {
       if (bounds_check->IsInBlock()) {
         TryDynamicBCE(bounds_check);
@@ -1467,7 +1469,9 @@ class BCEVisitor : public HGraphVisitor {
       }
       // If bounds check made it this far, it is worthwhile to check later if
       // the loop was forced finite by another candidate.
-      dynamic_bce_standby_.push_back(check);
+      if (record_dynamic_bce_standby_) {
+        dynamic_bce_standby_.push_back(check);
+      }
       return false;
     }
     return true;
@@ -1691,6 +1695,7 @@ class BCEVisitor : public HGraphVisitor {
 
   // Stand by list for dynamic bce.
   ArenaVector<HBoundsCheck*> dynamic_bce_standby_;
+  bool record_dynamic_bce_standby_;
 
   // Early-exit loop bookkeeping.
   ArenaSafeMap<uint32_t, bool> early_exit_loop_;