Add custom typed ICs for pixel array loads.

src/ic.cc

 // Copyright 2006-2009 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 1179 matching lines @@
   if (use_ic) {
     Code* stub = generic_stub();
     if (object->IsString() && key->IsNumber()) {
       stub = string_stub();
     } else if (object->IsJSObject()) {
       Handle<JSObject> receiver = Handle<JSObject>::cast(object);
       if (receiver->HasExternalArrayElements()) {
         MaybeObject* probe =
             StubCache::ComputeKeyedLoadOrStoreExternalArray(*receiver, false);
         stub =
-            probe->IsFailure() ? NULL : Code::cast(probe->ToObjectUnchecked());
+          probe->IsFailure() ? NULL : Code::cast(probe->ToObjectUnchecked());
+      } else if (receiver->HasPixelElements()) {
+        stub = pixel_array_stub();

[Mads Ager (chromium), 2011/01/25 14:49:17]

Let's remove the pixel array code in the generic stub now that we have a special
IC stub?

[danno, 2011/01/25 20:56:29]

This occurred to me too, but I actually think we still need it... Otherwise how
do we handle pixel arrays in the case of a call site that goes megamorphic?
On 2011/01/25 14:49:17, Mads Ager wrote:

[Mads Ager (chromium), 2011/01/26 08:10:21]

True, we don't deal with it in that case and I guess it will not harm much to
leave it in the generic stub. 

However, can we share some of the code generation code in that case? Create a
static helper method GenerateLoadFromPixelArray that generates the code for
everything but the receiver check?

On 2011/01/25 20:56:29, danno wrote:

       } else if (receiver->HasIndexedInterceptor()) {
         stub = indexed_interceptor_stub();
       } else if (state == UNINITIALIZED &&
                  key->IsSmi() &&
                  receiver->map()->has_fast_elements()) {
         MaybeObject* probe = StubCache::ComputeKeyedLoadSpecialized(*receiver);
         stub =
             probe->IsFailure() ? NULL : Code::cast(probe->ToObjectUnchecked());
       }
     }
@@ skipping 1019 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal