Replace tagged keys for fast access by smi, and use smi in boundscheck.

src/hydrogen.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 985 matching lines @@
   ASSERT(current_block() != NULL);
   ASSERT(no_side_effects_scope_count_ == 0);
   current_block()->AddSimulate(id, removable);
 }
 
 
 HBoundsCheck* HGraphBuilder::AddBoundsCheck(HValue* index,
                                             HValue* length,
                                             BoundsCheckKeyMode key_mode,
                                             Representation r) {
-  if (!index->type().IsSmi()) {
-    index = new(graph()->zone()) HCheckSmiOrInt32(index);
-    AddInstruction(HCheckSmiOrInt32::cast(index));
-  }
-  if (!length->type().IsSmi()) {
-    length = new(graph()->zone()) HCheckSmiOrInt32(length);
-    AddInstruction(HCheckSmiOrInt32::cast(length));
-  }
   HBoundsCheck* result = new(graph()->zone()) HBoundsCheck(
       index, length, key_mode, r);
   AddInstruction(result);
   return result;
 }
 
 
 HReturn* HGraphBuilder::AddReturn(HValue* value) {
   HValue* context = environment()->LookupContext();
   int num_parameters = graph()->info()->num_parameters();
@@ skipping 307 matching lines @@
   if (is_store && IsFastSmiElementsKind(elements_kind) &&
       !val->type().IsSmi()) {
     AddInstruction(new(zone) HCheckSmi(val));
   }
 
   if (IsGrowStoreMode(store_mode)) {
     NoObservableSideEffectsScope no_effects(this);
 
     elements = BuildCheckForCapacityGrow(object, elements, elements_kind,
                                          length, key, is_js_array);
-    if (!key->type().IsSmi()) {
-      checked_key = AddInstruction(new(zone) HCheckSmiOrInt32(key));
-    } else {
-      checked_key = key;
-    }
+    checked_key = key;
   } else {
     checked_key = AddBoundsCheck(
         key, length, ALLOW_SMI_KEY, checked_index_representation);
 
     if (is_store && (fast_elements || fast_smi_only_elements)) {
       if (store_mode == STORE_NO_TRANSITION_HANDLE_COW) {
         NoObservableSideEffectsScope no_effects(this);
 
         elements = BuildCopyElementsOnWrite(object, elements, elements_kind,
                                             length);
@@ skipping 11122 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal