Use xorps xmm1, xmm1 to creat a 0.0 cconstant. Add to utils a bitwise double test.

runtime/vm/intermediate_language_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 272 matching lines @@
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_out(0, Location::RequiresFpuRegister());
   locs->set_temp(0, Location::RequiresRegister());
   return locs;
 }
 
 
 void UnboxedConstantInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   // The register allocator drops constant definitions that have no uses.
   if (!locs()->out(0).IsInvalid()) {
-    DRegister dst = EvenDRegisterOf(locs()->out(0).fpu_reg());
-    Register temp = locs()->temp(0).reg();
-    __ LoadDImmediate(dst, Double::Cast(value()).value(), temp);
+    if (Utils::DoublesBitEqual(Double::Cast(value()).value(), 0.0)) {
+      QRegister dst = locs()->out(0).fpu_reg();
+      __ veorq(dst, dst, dst);
+    } else {
+      DRegister dst = EvenDRegisterOf(locs()->out(0).fpu_reg());
+      Register temp = locs()->temp(0).reg();
+      __ LoadDImmediate(dst, Double::Cast(value()).value(), temp);
+    }
   }
 }
 
 
 LocationSummary* AssertAssignableInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 3;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   summary->set_in(0, Location::RegisterLocation(R0));  // Value.
@@ skipping 5777 matching lines @@
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM