Optimized megamorphic stubs

runtime/vm/flow_graph_compiler_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/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1325 matching lines @@
     __ cmp(R0, Operand(0));
 
     __ b(&done, NE);  // Return if already computed.
     __ mov(R0, Operand(R9));  // Restore receiver in R0.
 
     __ Bind(&megamorphic_call);
     __ Comment("Slow case: megamorphic call");
   }
   __ LoadObject(R9, cache);
   if (FLAG_use_megamorphic_stub) {
-    __ BranchLink(*StubCode::MegamorphicLookup_entry());
+    __ ldr(LR, Address(THR, Thread::megamorphic_lookup_entry_point_offset()));
+    __ blx(LR);
   } else {
     StubCode::EmitMegamorphicLookup(assembler());
   }
   __ blx(R1);
 
   __ Bind(&done);
   RecordSafepoint(locs, slow_path_argument_count);
   const intptr_t deopt_id_after = Thread::ToDeoptAfter(deopt_id);
   if (FLAG_precompiled_mode) {
     // Megamorphic calls may occur in slow path stubs.
@@ skipping 641 matching lines @@
   DRegister dreg = EvenDRegisterOf(reg);
   __ vldrd(dreg, Address(SP, kDoubleSize, Address::PostIndex));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM