ART: Rediscover loops after deleting blocks in DCE

The way DCE currently updates loop information does not cover all
cases. This patch removes the logic, resets loop information of live
blocks to pre-SSA state and reanalyzes the affected loops.

Change-Id: I0b996a70235b95a8db0de9a23a03f71db57a21b8
(cherry picked from commit a4b8c21dae70ae34aee13628632c39a675c06022)

1 files changed, 4 insertions, 2 deletions

diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index e993d778d4..8bb5d8ebae 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -320,8 +320,10 @@ static void RunOptimizations(HGraph* graph,
                              const DexCompilationUnit& dex_compilation_unit,
                              PassInfoPrinter* pass_info_printer,
                              StackHandleScopeCollection* handles) {
-  HDeadCodeElimination dce1(graph, stats);
-  HDeadCodeElimination dce2(graph, stats, "dead_code_elimination_final");
+  HDeadCodeElimination dce1(graph, stats,
+                            HDeadCodeElimination::kInitialDeadCodeEliminationPassName);
+  HDeadCodeElimination dce2(graph, stats,
+                            HDeadCodeElimination::kFinalDeadCodeEliminationPassName);
   HConstantFolding fold1(graph);
   InstructionSimplifier simplify1(graph, stats);
   HBooleanSimplifier boolean_simplify(graph);