Implement fast calls of functions in the presence of eval (if the eval...

src/x64/codegen-x64.cc

 // Copyright 2010 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 2848 matching lines @@
     Result result = frame_->CallCallIC(RelocInfo::CODE_TARGET_CONTEXT,
                                        arg_count,
                                        loop_nesting());
     frame_->RestoreContextRegister();
     // Replace the function on the stack with the result.
     frame_->Push(&result);
 
   } else if (var != NULL && var->slot() != NULL &&
              var->slot()->type() == Slot::LOOKUP) {
     // ----------------------------------
-    // JavaScript example: 'with (obj) foo(1, 2, 3)'  // foo is in obj
+    // JavaScript examples:
+    //
+    //  with (obj) foo(1, 2, 3)  // foo is in obj
+    //
+    //  function f() {};
+    //  function g() {
+    //    eval(...);
+    //    f();  // f could be in extension object
+    //  }
     // ----------------------------------
 
+    JumpTarget slow;
+    JumpTarget done;
+
+    // Generate fast-case code for variables that might be shadowed by
+    // eval-introduced variables.  Eval is used a lot without
+    // introducing variables.  In those cases, we do not want to
+    // perform a runtime call for all variables in the scope
+    // containing the eval.
+    Result function;
+    if (var->mode() == Variable::DYNAMIC_GLOBAL) {
+      function = LoadFromGlobalSlotCheckExtensions(var->slot(),
+                                                   NOT_INSIDE_TYPEOF,
+                                                   &slow);
+      frame_->Push(&function);
+      LoadGlobalReceiver();
+      done.Jump();
+
+    } else if (var->mode() == Variable::DYNAMIC_LOCAL) {
+      Slot* potential_slot = var->local_if_not_shadowed()->slot();
+      // Only generate the fast case for locals that rewrite to slots.
+      // This rules out argument loads because eval forces arguments
+      // access to be through the arguments object.
+      if (potential_slot != NULL) {
+        // Allocate a fresh register to use as a temp in
+        // ContextSlotOperandCheckExtensions and to hold the result
+        // value.
+        function = allocator()->Allocate();
+        ASSERT(function.is_valid());
+        __ movq(function.reg(),
+                ContextSlotOperandCheckExtensions(potential_slot,
+                                                  function,
+                                                  &slow));
+        JumpTarget push_function_and_receiver;
+        if (potential_slot->var()->mode() == Variable::CONST) {
+          __ CompareRoot(function.reg(), Heap::kTheHoleValueRootIndex);
+          push_function_and_receiver.Branch(not_equal, &function);
+          __ LoadRoot(function.reg(), Heap::kUndefinedValueRootIndex);
+        }
+        push_function_and_receiver.Bind(&function);
+        frame_->Push(&function);
+        LoadGlobalReceiver();
+        done.Jump();
+      }
+    }
+
+    slow.Bind();
     // Load the function from the context.  Sync the frame so we can
     // push the arguments directly into place.
     frame_->SyncRange(0, frame_->element_count() - 1);
     frame_->EmitPush(rsi);
     frame_->EmitPush(var->name());
     frame_->CallRuntime(Runtime::kLoadContextSlot, 2);
     // The runtime call returns a pair of values in rax and rdx.  The
     // looked-up function is in rax and the receiver is in rdx.  These
     // register references are not ref counted here.  We spill them
     // eagerly since they are arguments to an inevitable call (and are
     // not sharable by the arguments).
     ASSERT(!allocator()->is_used(rax));
     frame_->EmitPush(rax);
 
     // Load the receiver.
     ASSERT(!allocator()->is_used(rdx));
     frame_->EmitPush(rdx);
 
+    done.Bind();
     // Call the function.
     CallWithArguments(args, NO_CALL_FUNCTION_FLAGS, node->position());
 
   } else if (property != NULL) {
     // Check if the key is a literal string.
     Literal* literal = property->key()->AsLiteral();
 
     if (literal != NULL && literal->handle()->IsSymbol()) {
       // ------------------------------------------------------------------
       // JavaScript example: 'object.foo(1, 2, 3)' or 'map["key"](1, 2, 3)'
@@ skipping 2271 matching lines @@
       if (!slow.is_linked()) {
         frame_->Push(&value);
         return;
       }
 
       done.Jump(&value);
 
     } else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
       Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
       // Only generate the fast case for locals that rewrite to slots.
-      // This rules out argument loads.
+      // This rules out argument loads because eval forces arguments
+      // access to be through the arguments object.
       if (potential_slot != NULL) {
         // Allocate a fresh register to use as a temp in
         // ContextSlotOperandCheckExtensions and to hold the result
         // value.
         value = allocator_->Allocate();
         ASSERT(value.is_valid());
         __ movq(value.reg(),
                ContextSlotOperandCheckExtensions(potential_slot,
                                                  value,
                                                  &slow));
@@ skipping 6265 matching lines @@
   // Call the function from C++.
   return FUNCTION_CAST<ModuloFunction>(buffer);
 }
 
 #endif
 
 
 #undef __
 
 } }  // namespace v8::internal