MIPS: Support slow-mode prototypes for load and call ICs.

src/mips/stub-cache-mips.cc

 // Copyright 2012 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 2875 matching lines @@
   __ bind(&miss);
   __ IncrementCounter(counters->named_store_global_inline_miss(), 1, a1, a3);
   Handle<Code> ic = masm()->isolate()->builtins()->StoreIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode(Code::NORMAL, name);
 }
 
 
-Handle<Code> LoadStubCompiler::CompileLoadNonexistent(Handle<String> name,
-                                                      Handle<JSObject> object,
-                                                      Handle<JSObject> last) {
+Handle<Code> LoadStubCompiler::CompileLoadNonexistent(
+    Handle<String> name,
+    Handle<JSObject> object,
+    Handle<JSObject> last,
+    Handle<GlobalObject> global) {
   // ----------- S t a t e -------------
   //  -- a0    : receiver
   //  -- ra    : return address
   // -----------------------------------
   Label miss;
 
   // Check that the receiver is not a smi.
   __ JumpIfSmi(a0, &miss);
 
+  Register scratch = a1;
+
   // Check the maps of the full prototype chain.
-  CheckPrototypes(object, a0, last, a3, a1, t0, name, &miss);
+  Register result =
+      CheckPrototypes(object, a0, last, a3, scratch, t0, name, &miss);
 
   // If the last object in the prototype chain is a global object,
   // check that the global property cell is empty.
-  if (last->IsGlobalObject()) {
-    GenerateCheckPropertyCell(
-        masm(), Handle<GlobalObject>::cast(last), name, a1, &miss);
+  if (!global.is_null()) {
+    GenerateCheckPropertyCell(masm(), global, name, scratch, &miss);
+  }
+
+  if (!last->HasFastProperties()) {
+    __ lw(scratch, FieldMemOperand(result, HeapObject::kMapOffset));
+    __ lw(scratch, FieldMemOperand(scratch, Map::kPrototypeOffset));
+    __ Branch(&miss, ne, scratch, Operand(isolate()->factory()->null_value()));
   }
 
   // Return undefined if maps of the full prototype chain is still the same.
   __ LoadRoot(v0, Heap::kUndefinedValueRootIndex);
   __ Ret();
 
   __ bind(&miss);
   GenerateLoadMiss(masm(), Code::LOAD_IC);
 
   // Return the generated code.
@@ skipping 1442 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS