Reland 21774: Generate KeyedLoadGeneric with Hydrogen

src/hydrogen-instructions.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 2641 matching lines @@
 bool HConstant::EmitAtUses() {
   ASSERT(IsLinked());
   if (block()->graph()->has_osr() &&
       block()->graph()->IsStandardConstant(this)) {
     // TODO(titzer): this seems like a hack that should be fixed by custom OSR.
     return true;
   }
   if (UseCount() == 0) return true;
   if (IsCell()) return false;
   if (representation().IsDouble()) return false;
+  if (representation().IsExternal()) return false;
   return true;
 }
 
 
 HConstant* HConstant::CopyToRepresentation(Representation r, Zone* zone) const {
   if (r.IsSmi() && !has_smi_value_) return NULL;
   if (r.IsInteger32() && !has_int32_value_) return NULL;
   if (r.IsDouble() && !has_double_value_) return NULL;
   if (r.IsExternal() && !has_external_reference_value_) return NULL;
   if (has_int32_value_) {
@@ skipping 451 matching lines @@
     ASSERT(elements_kind() >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND &&
            elements_kind() <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND);
     elements()->PrintNameTo(stream);
     stream->Add(".");
     stream->Add(ElementsKindToString(elements_kind()));
   }
 
   stream->Add("[");
   key()->PrintNameTo(stream);
   if (IsDehoisted()) {
-    stream->Add(" + %d]", index_offset());
+    stream->Add(" + %d]", base_offset());
   } else {
     stream->Add("]");
   }
 
   if (HasDependency()) {
     stream->Add(" ");
     dependency()->PrintNameTo(stream);
   }
 
   if (RequiresHoleCheck()) {
@@ skipping 80 matching lines @@
             HCheckMapValue::New(block()->graph()->zone(),
                                 block()->graph()->GetInvalidContext(),
                                 object(),
                                 names_cache->map());
         HInstruction* index = HLoadKeyed::New(
             block()->graph()->zone(),
             block()->graph()->GetInvalidContext(),
             index_cache,
             key_load->key(),
             key_load->key(),
-            key_load->elements_kind());
+            key_load->elements_kind(),

[Toon Verwaest, 2013/12/04 17:29:26]

Why is this the same elements kind as the array of names? Wouldn't it make more
sense to know that the index cache is eg a FAST_SMI_ELEMENTS array, so that we
can avoid smi-checks? (For the future), even better, why don't we make the cache
external ints or so, so the HLoadFieldByIndex automatically gets the int without
any conversions?

[danno, 2014/06/06 15:43:50]

That's beyond the scope of this change, which itself is no longer necessary
anyway after unrelated changes to HLoadFieldByIndex, the for-in case remains as
it always has been.

+            NEVER_RETURN_HOLE,
+            key_load->base_offset());
         map_check->InsertBefore(this);
         index->InsertBefore(this);
-        HLoadFieldByIndex* load = new(block()->zone()) HLoadFieldByIndex(
-            object(), index);
+        HInstruction* int_index = new(block()->zone()) HChange(
+            index, Representation::Integer32(), false, false);
+        HChange::cast(int_index)->InsertBefore(this);

[Toon Verwaest, 2013/12/04 17:29:26]

So this change is actually (or better, will be) superflous.

[danno, 2014/06/06 15:43:50]

This change is no longer necessary, after unrelated changes to
HLoadFieldByIndex, the for-in case remains as it always has been.

+        HLoadFieldByIndex* load =
+            HLoadFieldByIndex::New(block()->graph()->zone(),
+                                   block()->graph()->GetInvalidContext(),
+                                   object(),
+                                   int_index);
         load->InsertBefore(this);
         return load;
       }
     }
   }
 
   return this;
 }
 
 
@@ skipping 28 matching lines @@
     elements()->PrintNameTo(stream);
     stream->Add(".");
     stream->Add(ElementsKindToString(elements_kind()));
     ASSERT(elements_kind() >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND &&
            elements_kind() <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND);
   }
 
   stream->Add("[");
   key()->PrintNameTo(stream);
   if (IsDehoisted()) {
-    stream->Add(" + %d] = ", index_offset());
+    stream->Add(" + %d] = ", base_offset());
   } else {
     stream->Add("] = ");
   }
 
   value()->PrintNameTo(stream);
 }
 
 
 void HStoreKeyedGeneric::PrintDataTo(StringStream* stream) {
   object()->PrintNameTo(stream);
@@ skipping 1115 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal