Better support for 'polymorphic' JS and external arrays

src/arm/macro-assembler-arm.cc

 // Copyright 2011 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 1663 matching lines @@
   if (smi_check_type == DO_SMI_CHECK) {
     JumpIfSmi(obj, fail);
   }
   ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
   LoadRoot(ip, index);
   cmp(scratch, ip);
   b(ne, fail);
 }
 
 
+void MacroAssembler::DispatchMap(Register obj,
+                                 Register scratch,
+                                 Handle<Map> map,
+                                 Handle<Code> success,
+                                 SmiCheckType smi_check_type) {
+  Label fail;
+  if (smi_check_type == DO_SMI_CHECK) {
+    JumpIfSmi(obj, &fail);
+  }
+  ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
+  mov(ip, Operand(map));
+  cmp(scratch, ip);
+  Jump(success, RelocInfo::CODE_TARGET, eq);
+  bind(&fail);
+}
+
+
 void MacroAssembler::TryGetFunctionPrototype(Register function,
                                              Register result,
                                              Register scratch,
                                              Label* miss) {
   // Check that the receiver isn't a smi.
   JumpIfSmi(function, miss);
 
   // Check that the function really is a function.  Load map into result reg.
   CompareObjectType(function, result, scratch, JS_FUNCTION_TYPE);
   b(ne, miss);
@@ skipping 1407 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM