Migrate instance of deprecated maps in HCheckMaps.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 33aca06bc7bbe8e72eb1bbd17a417fa9442d70b9..27d3f1923c2383f20077219f99fd8cb4c61862a3 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -5214,33 +5214,69 @@ void LCodeGen::DoCheckFunction(LCheckFunction* instr) {
 }
 
 
-void LCodeGen::DoCheckMapCommon(Register map_reg,
-                                Handle<Map> map,
-                                LEnvironment* env) {
-  Label success;
-  __ CompareMap(map_reg, map, &success);
-  DeoptimizeIf(ne, env);
-  __ bind(&success);
+void LCodeGen::DoDeferredInstanceMigration(LCheckMaps* instr, Register object) {
+  {
+    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
+    __ push(object);
+    CallRuntimeFromDeferred(Runtime::kMigrateInstance, 1, instr);
+    __ StoreToSafepointRegisterSlot(scratch0(), r0);
+  }
+  __ tst(scratch0(), Operand(kSmiTagMask));
+  DeoptimizeIf(eq, instr->environment());
 }
 
 
 void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
+  class DeferredInstanceMigration: public LDeferredCode {
+   public:
+    DeferredInstanceMigration(LCodeGen* codegen,
+                              LCheckMaps* instr,
+                              Register object)
+        : LDeferredCode(codegen), instr_(instr), object_(object) {
+      SetExit(check_maps());
+    }
+    virtual void Generate() {
+      codegen()->DoDeferredInstanceMigration(instr_, object_);
+    }
+    Label* check_maps() { return &check_maps_; }
+    virtual LInstruction* instr() { return instr_; }
+   private:
+    LCheckMaps* instr_;
+    Label check_maps_;
+    Register object_;
+  };
+
   if (instr->hydrogen()->CanOmitMapChecks()) return;
   Register map_reg = scratch0();
+
   LOperand* input = instr->value();
   ASSERT(input->IsRegister());
   Register reg = ToRegister(input);
 
-  Label success;
   SmallMapList* map_set = instr->hydrogen()->map_set();
   __ ldr(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
+
+  DeferredInstanceMigration* deferred = NULL;
+  if (instr->hydrogen()->has_migration_target()) {
+    deferred = new(zone()) DeferredInstanceMigration(this, instr, reg);
+    __ bind(deferred->check_maps());
+  }
+
+  Label success;
   for (int i = 0; i < map_set->length() - 1; i++) {
     Handle<Map> map = map_set->at(i);
     __ CompareMap(map_reg, map, &success);
     __ b(eq, &success);
   }
+
   Handle<Map> map = map_set->last();
-  DoCheckMapCommon(map_reg, map, instr->environment());
+  __ CompareMap(map_reg, map, &success);
+  if (instr->hydrogen()->has_migration_target()) {
+    __ b(ne, deferred->entry());
+  } else {
+    DeoptimizeIf(ne, instr->environment());
+  }
+
   __ bind(&success);
 }