[turbofan] Some javascript operators are globally shared singletons.

src/compiler/js-context-specialization.cc

 // Copyright 2014 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/common-operator.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/graph-inl.h"
 #include "src/compiler/js-context-specialization.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node-aux-data-inl.h"
@@ skipping 49 matching lines @@
 
 Reduction JSContextSpecializer::ReduceJSLoadContext(Node* node) {
   DCHECK_EQ(IrOpcode::kJSLoadContext, node->opcode());
 
   HeapObjectMatcher<Context> m(NodeProperties::GetValueInput(node, 0));
   // If the context is not constant, no reduction can occur.
   if (!m.HasValue()) {
     return Reducer::NoChange();
   }
 
-  ContextAccess access = OpParameter<ContextAccess>(node);
+  const ContextAccess& access = ContextAccessOf(node->op());
 
   // Find the right parent context.
   Context* context = *m.Value().handle();
-  for (int i = access.depth(); i > 0; --i) {
+  for (size_t i = access.depth(); i > 0; --i) {
     context = context->previous();
   }
 
   // If the access itself is mutable, only fold-in the parent.
   if (!access.immutable()) {
     // The access does not have to look up a parent, nothing to fold.
     if (access.depth() == 0) {
       return Reducer::NoChange();
     }
     const Operator* op = jsgraph_->javascript()->LoadContext(
         0, access.index(), access.immutable());
     node->set_op(op);
     Handle<Object> context_handle = Handle<Object>(context, info_->isolate());
     node->ReplaceInput(0, jsgraph_->Constant(context_handle));
     return Reducer::Changed(node);
   }
-  Handle<Object> value =
-      Handle<Object>(context->get(access.index()), info_->isolate());
+  Handle<Object> value = Handle<Object>(
+      context->get(static_cast<int>(access.index())), info_->isolate());
 
   // Even though the context slot is immutable, the context might have escaped
   // before the function to which it belongs has initialized the slot.
   // We must be conservative and check if the value in the slot is currently the
   // hole or undefined. If it is neither of these, then it must be initialized.
   if (value->IsUndefined() || value->IsTheHole()) {
     return Reducer::NoChange();
   }
 
   // Success. The context load can be replaced with the constant.
   // TODO(titzer): record the specialization for sharing code across multiple
   // contexts that have the same value in the corresponding context slot.
   return Reducer::Replace(jsgraph_->Constant(value));
 }
 
 
 Reduction JSContextSpecializer::ReduceJSStoreContext(Node* node) {
   DCHECK_EQ(IrOpcode::kJSStoreContext, node->opcode());
 
   HeapObjectMatcher<Context> m(NodeProperties::GetValueInput(node, 0));
   // If the context is not constant, no reduction can occur.
   if (!m.HasValue()) {
     return Reducer::NoChange();
   }
 
-  ContextAccess access = OpParameter<ContextAccess>(node);
+  const ContextAccess& access = ContextAccessOf(node->op());
 
   // The access does not have to look up a parent, nothing to fold.
   if (access.depth() == 0) {
     return Reducer::NoChange();
   }
 
   // Find the right parent context.
   Context* context = *m.Value().handle();
-  for (int i = access.depth(); i > 0; --i) {
+  for (size_t i = access.depth(); i > 0; --i) {
     context = context->previous();
   }
 
   const Operator* op = jsgraph_->javascript()->StoreContext(0, access.index());
   node->set_op(op);
   Handle<Object> new_context_handle = Handle<Object>(context, info_->isolate());
   node->ReplaceInput(0, jsgraph_->Constant(new_context_handle));
 
   return Reducer::Changed(node);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8