Harmony: optimize Math.clz32.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3850 matching lines @@
 
 void LCodeGen::DoMathLog(LMathLog* instr) {
   __ PrepareCallCFunction(0, 1, scratch0());
   __ MovToFloatParameter(ToDoubleRegister(instr->value()));
   __ CallCFunction(ExternalReference::math_log_double_function(isolate()),
                    0, 1);
   __ MovFromFloatResult(ToDoubleRegister(instr->result()));
 }
 
 
+void LCodeGen::DoMathClz32(LMathClz32* instr) {
+  Register input = ToRegister(instr->value());
+  Register result = ToRegister(instr->result());
+  __ clz(result, input);
+}
+
+
 void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
   ASSERT(ToRegister(instr->context()).is(cp));
   ASSERT(ToRegister(instr->function()).is(r1));
   ASSERT(instr->HasPointerMap());
 
   Handle<JSFunction> known_function = instr->hydrogen()->known_function();
   if (known_function.is_null()) {
     LPointerMap* pointers = instr->pointer_map();
     SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
     ParameterCount count(instr->arity());
@@ skipping 1854 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal