Cleanup of class id loading sequences.

runtime/vm/intermediate_language_arm64.cc

 // Copyright (c) 2014, 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_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 889 matching lines @@
   return LocationSummary::Make(isolate,
                                kNumInputs,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void LoadClassIdInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   const Register object = locs()->in(0).reg();
   const Register result = locs()->out(0).reg();
-  __ LoadTaggedClassIdMayBeSmi(result, object);
+  static const intptr_t kSmiCidSource = kSmiCid << RawObject::kClassIdTagPos;
+
+  __ LoadImmediate(TMP, reinterpret_cast<int64_t>(&kSmiCidSource) + 1, PP);
+  __ tsti(object, kSmiTagMask);
+  __ csel(TMP, TMP, object, EQ);
+  __ LoadClassId(result, TMP, PP);
+  __ SmiTag(result);
 }
 
 
 CompileType LoadIndexedInstr::ComputeType() const {
   switch (class_id_) {
     case kArrayCid:
     case kImmutableArrayCid:
       return CompileType::Dynamic();
 
     case kTypedDataFloat32ArrayCid:
@@ skipping 4589 matching lines @@
   compiler->GenerateCall(token_pos(), &label, stub_kind_, locs());
 #if defined(DEBUG)
   __ LoadImmediate(R4, kInvalidObjectPointer, kNoPP);
   __ LoadImmediate(R5, kInvalidObjectPointer, kNoPP);
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64