Run a simplification pass before code generation.

The code generators assume things that only the instruction
simplier ensures. So it has to be run last in case previous
optimiziations broke those assumptions.

bug:21865464

(cherry picked from commit b2bdfce7f805b00668a2521b1c939a0aafb2be49)

Change-Id: Ibf4384a911e400eb7586bbf6b4edd6351034cbd8

1 files changed, 5 insertions, 0 deletions

diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index 64d6023fba..810b4f8f8f 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -337,6 +337,7 @@ static void RunOptimizations(HGraph* graph,
   BoundsCheckElimination bce(graph);
   ReferenceTypePropagation type_propagation(graph, dex_file, dex_compilation_unit, handles);
   InstructionSimplifier simplify2(graph, stats, "instruction_simplifier_after_types");
+  InstructionSimplifier simplify3(graph, stats, "instruction_simplifier_before_codegen");
 
   IntrinsicsRecognizer intrinsics(graph, dex_compilation_unit.GetDexFile(), driver);
 
@@ -357,6 +358,10 @@ static void RunOptimizations(HGraph* graph,
     &type_propagation,
     &simplify2,
     &dce2,
+    // The codegen has a few assumptions that only the instruction simplifier can
+    // satisfy. For example, the code generator does not expect to see a
+    // HTypeConversion from a type to the same type.
+    &simplify3,
   };
 
   RunOptimizations(optimizations, arraysize(optimizations), pass_info_printer);