[turbofan] Specialize to (optimization time) known TypedArray instances.

src/compiler/effect-control-linearizer.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/effect-control-linearizer.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
@@ skipping 3195 matching lines @@
   ExternalArrayType array_type = ExternalArrayTypeOf(node->op());
   Node* buffer = node->InputAt(0);
   Node* base = node->InputAt(1);
   Node* external = node->InputAt(2);
   Node* index = node->InputAt(3);
 
   // We need to keep the {buffer} alive so that the GC will not release the
   // ArrayBuffer (if there's any) as long as we are still operating on it.
   effect = graph()->NewNode(common()->Retain(), buffer, effect);
 
-  // Compute the effective storage pointer.
-  Node* storage = effect = graph()->NewNode(machine()->UnsafePointerAdd(), base,
-                                            external, effect, control);
+  // Compute the effective storage pointer, handling the case where the
+  // {external} pointer is the effective storage pointer (i.e. the {base}
+  // is Smi zero).
+  Node* storage =
+      NumberMatcher(base).Is(0)
+          ? external
+          : effect = graph()->NewNode(machine()->UnsafePointerAdd(), base,
+                                      external, effect, control);
 
   // Perform the actual typed element access.
   Node* value = effect = graph()->NewNode(
       simplified()->LoadElement(
           AccessBuilder::ForTypedArrayElement(array_type, true)),
       storage, index, effect, control);
 
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerStoreTypedElement(Node* node, Node* effect,
                                                 Node* control) {
   ExternalArrayType array_type = ExternalArrayTypeOf(node->op());
   Node* buffer = node->InputAt(0);
   Node* base = node->InputAt(1);
   Node* external = node->InputAt(2);
   Node* index = node->InputAt(3);
   Node* value = node->InputAt(4);
 
   // We need to keep the {buffer} alive so that the GC will not release the
   // ArrayBuffer (if there's any) as long as we are still operating on it.
   effect = graph()->NewNode(common()->Retain(), buffer, effect);
 
-  // Compute the effective storage pointer.
-  Node* storage = effect = graph()->NewNode(machine()->UnsafePointerAdd(), base,
-                                            external, effect, control);
+  // Compute the effective storage pointer, handling the case where the
+  // {external} pointer is the effective storage pointer (i.e. the {base}
+  // is Smi zero).
+  Node* storage =
+      NumberMatcher(base).Is(0)
+          ? external
+          : effect = graph()->NewNode(machine()->UnsafePointerAdd(), base,
+                                      external, effect, control);
 
   // Perform the actual typed element access.
   effect = graph()->NewNode(
       simplified()->StoreElement(
           AccessBuilder::ForTypedArrayElement(array_type, true)),
       storage, index, value, effect, control);
 
   return ValueEffectControl(nullptr, effect, control);
 }
 
@@ skipping 498 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kEliminatable);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8