Opt compiler: Instruction simplification for HAdd, HNeg, HNot, HSub.

Under assumptions for the 'cost' of each IR (eg. neither HAdd nor HSub
are faster than the other), transformations are only applied if they
(locally) cannot degrade the quality of the graph. The code could be
extended to look at uses of the IRs and detect more opportunities for
optimisations.  The optimisations in this patch do not look at other
uses for their inputs.

Change-Id: Ib60dab007af30f43421ef5bb55db2ec32fb8fc0c

1 files changed, 2 insertions, 0 deletions

diff --git a/compiler/optimizing/optimizing_compiler_stats.h b/compiler/optimizing/optimizing_compiler_stats.h
index b97a66719d..4d5b8d0639 100644
--- a/compiler/optimizing/optimizing_compiler_stats.h
+++ b/compiler/optimizing/optimizing_compiler_stats.h
@@ -47,6 +47,7 @@ enum MethodCompilationStat {
   kNotCompiledUnhandledInstruction,
   kRemovedCheckedCast,
   kRemovedNullCheck,
+  kInstructionSimplifications,
   kLastStat
 };
 
@@ -110,6 +111,7 @@ class OptimizingCompilerStats {
       case kNotCompiledUnhandledInstruction : return "kNotCompiledUnhandledInstruction";
       case kRemovedCheckedCast: return "kRemovedCheckedCast";
       case kRemovedNullCheck: return "kRemovedNullCheck";
+      case kInstructionSimplifications: return "kInstructionSimplifications";
       default: LOG(FATAL) << "invalid stat";
     }
     return "";