Improve performance of allocating closures for nested...

bleeding_edge/src/ia32/stub-cache-ia32.cc

 // Copyright 2006-2009 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 1136 matching lines @@
   }
 
   // Check that the maps haven't changed.
   CheckPrototypes(object, edx, holder, ebx, ecx, name, &miss);
 
   // Get the value from the cell.
   __ mov(edi, Immediate(Handle<JSGlobalPropertyCell>(cell)));
   __ mov(edi, FieldOperand(edi, JSGlobalPropertyCell::kValueOffset));
 
   // Check that the cell contains the same function.
-  __ cmp(Operand(edi), Immediate(Handle<JSFunction>(function)));
-  __ j(not_equal, &miss, not_taken);
+  if (Heap::InNewSpace(function)) {
+    // We can't embed a pointer to a function in new space so we have
+    // to verify that the shared function info is unchanged. This has
+    // the nice side effect that multiple closures based on the same
+    // function can all use this call IC. Before we load through the
+    // function, we have to verify that it still is a function.
+    __ test(edi, Immediate(kSmiTagMask));
+    __ j(zero, &miss, not_taken);
+    __ CmpObjectType(edi, JS_FUNCTION_TYPE, ebx);
+    __ j(not_equal, &miss, not_taken);
+
+    // Check the shared function info. Make sure it hasn't changed.
+    __ cmp(FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset),
+           Immediate(Handle<SharedFunctionInfo>(function->shared())));
+    __ j(not_equal, &miss, not_taken);
+  } else {
+    __ cmp(Operand(edi), Immediate(Handle<JSFunction>(function)));
+    __ j(not_equal, &miss, not_taken);
+  }
 
   // Patch the receiver on the stack with the global proxy.
   if (object->IsGlobalObject()) {
     __ mov(edx, FieldOperand(edx, GlobalObject::kGlobalReceiverOffset));
     __ mov(Operand(esp, (argc + 1) * kPointerSize), edx);
   }
 
   // Setup the context (function already in edi).
   __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
 
@@ skipping 729 matching lines @@
   __ jmp(generic_construct_stub, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal