Implement crankshaft support for pixel array stores.

src/hydrogen.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 3308 matching lines @@
     }
 
   } else {
     // Keyed store.
     VISIT_FOR_VALUE(prop->key());
     VISIT_FOR_VALUE(expr->value());
     value = Pop();
     HValue* key = Pop();
     HValue* object = Pop();
 
-    bool is_fast_elements = expr->IsMonomorphic() &&
-        expr->GetMonomorphicReceiverType()->has_fast_elements();
-
-    instr = is_fast_elements
-        ? BuildStoreKeyedFastElement(object, key, value, expr)
-        : BuildStoreKeyedGeneric(object, key, value);
+    if (expr->IsMonomorphic()) {
+      Handle<Map> receiver_type(expr->GetMonomorphicReceiverType());
+      // An object has either fast elements or pixel array elements, but never
+      // both. Pixel array maps that are assigned to pixel array elements are
+      // always created with the fast elements flag cleared.
+      if (receiver_type->has_pixel_array_elements()) {
+        instr = BuildStoreKeyedPixelArrayElement(object, key, value, expr);
+      } else if (receiver_type->has_fast_elements()) {
+        instr = BuildStoreKeyedFastElement(object, key, value, expr);
+      }
+    }
+    if (instr == NULL) {
+      instr = BuildStoreKeyedGeneric(object, key, value);
+    }
   }
 
   Push(value);
   instr->set_position(expr->position());
   AddInstruction(instr);
   if (instr->HasSideEffects()) AddSimulate(expr->AssignmentId());
   ast_context()->ReturnValue(Pop());
 }
 
 
@@ skipping 398 matching lines @@
   if (is_array) {
     length = AddInstruction(new HJSArrayLength(object));
   } else {
     length = AddInstruction(new HFixedArrayLength(elements));
   }
   AddInstruction(new HBoundsCheck(key, length));
   return new HStoreKeyedFastElement(elements, key, val);
 }
 
 
+HInstruction* HGraphBuilder::BuildStoreKeyedPixelArrayElement(HValue* object,
+                                                              HValue* key,
+                                                              HValue* val,
+                                                              Expression* expr) {
+  ASSERT(expr->IsMonomorphic());
+  AddInstruction(new HCheckNonSmi(object));
+  Handle<Map> map = expr->GetMonomorphicReceiverType();
+  ASSERT(!map->has_fast_elements());
+  ASSERT(map->has_pixel_array_elements());
+  AddInstruction(new HCheckMap(object, map));
+  HLoadElements* elements = new HLoadElements(object);
+  AddInstruction(elements);
+  HInstruction* length = AddInstruction(new HPixelArrayLength(elements));

[Kevin Millikin (Chromium), 2011/02/16 08:51:25]

Wow, AddInstruction returns a value and we usually ignore it?  Who knew.

I think I'd rather just make it have a side effect and no retrun value (as a
separate change).  Return values that are normally ignored seems like a bad
smell.

Could you write this statement as two separate ones:

HInstruction* length = new HPixelArrayLength(elements);
AddInstruction(length);

[danno, 2011/02/16 13:54:22]

Done.

+  AddInstruction(new HBoundsCheck(key, length));
+  HLoadPixelArrayExternalPointer* external_elements =
+      new HLoadPixelArrayExternalPointer(elements);
+  AddInstruction(external_elements);
+  return new HStorePixelArrayElement(external_elements, key, val);
+}
+
+
 bool HGraphBuilder::TryArgumentsAccess(Property* expr) {
   VariableProxy* proxy = expr->obj()->AsVariableProxy();
   if (proxy == NULL) return false;
   if (!proxy->var()->IsStackAllocated()) return false;
   if (!environment()->Lookup(proxy->var())->CheckFlag(HValue::kIsArguments)) {
     return false;
   }
 
   HInstruction* result = NULL;
   if (expr->key()->IsPropertyName()) {
@@ skipping 2209 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal