Harmony: optimize Math.clz32.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index fdf4ddfd804026dbdc38dad0ff78ab06f6b9bdc8..3242b19ac7ae046ad03ca408c4701cd1057ce113 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -1098,6 +1098,7 @@ LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
     case kMathExp: return DoMathExp(instr);
     case kMathSqrt: return DoMathSqrt(instr);
     case kMathPowHalf: return DoMathPowHalf(instr);
+    case kMathClz32: return DoMathClz32(instr);
     default:
       UNREACHABLE();
       return NULL;
@@ -1139,6 +1140,13 @@ LInstruction* LChunkBuilder::DoMathLog(HUnaryMathOperation* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoMathClz32(HUnaryMathOperation* instr) {
+  LOperand* input = UseRegisterAtStart(instr->value());
+  LMathClz32* result = new(zone()) LMathClz32(input);
+  return DefineAsRegister(result);
+}
+
+
 LInstruction* LChunkBuilder::DoMathExp(HUnaryMathOperation* instr) {
   ASSERT(instr->representation().IsDouble());
   ASSERT(instr->value()->representation().IsDouble());