Fix an assertion failure in the full code generator.

src/x64/full-codegen-x64.cc

 // Copyright 2011 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 1988 matching lines @@
     if (key != NULL && key->handle()->IsSymbol()) {
       // Call to a named property, use call IC.
       { PreservePositionScope scope(masm()->positions_recorder());
         VisitForStackValue(prop->obj());
       }
       EmitCallWithIC(expr, key->handle(), RelocInfo::CODE_TARGET);
     } else {
       // Call to a keyed property.
       // For a synthetic property use keyed load IC followed by function call,
       // for a regular property use keyed EmitCallIC.
-      { PreservePositionScope scope(masm()->positions_recorder());
-        VisitForStackValue(prop->obj());
-      }
       if (prop->is_synthetic()) {
-        { PreservePositionScope scope(masm()->positions_recorder());
-          VisitForAccumulatorValue(prop->key());
-        }
+        // Do not visit the object and key subexpressions (they are shared
+        // by all occurrences of the same rewritten parameter).
+        ASSERT(prop->obj()->AsVariableProxy() != NULL);
+        ASSERT(prop->obj()->AsVariableProxy()->var()->AsSlot() != NULL);
+        Slot* slot = prop->obj()->AsVariableProxy()->var()->AsSlot();
+        MemOperand operand = EmitSlotSearch(slot, rdx);
+        __ movq(rdx, operand);
+
+        ASSERT(prop->key()->AsLiteral() != NULL);
+        ASSERT(prop->key()->AsLiteral()->handle()->IsSmi());
+        __ Move(rax, prop->key()->AsLiteral()->handle());
+
         // Record source code position for IC call.
         SetSourcePosition(prop->position());
-        __ pop(rdx);  // We do not need to keep the receiver.
 
         Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
         EmitCallIC(ic, RelocInfo::CODE_TARGET);
         // Push result (function).
         __ push(rax);
         // Push Global receiver.
         __ movq(rcx, GlobalObjectOperand());
         __ push(FieldOperand(rcx, GlobalObject::kGlobalReceiverOffset));
         EmitCallWithStub(expr);
       } else {
+        { PreservePositionScope scope(masm()->positions_recorder());
+          VisitForStackValue(prop->obj());
+        }
         EmitKeyedCallWithIC(expr, prop->key(), RelocInfo::CODE_TARGET);
       }
     }
   } else {
     // Call to some other expression.  If the expression is an anonymous
     // function literal not called in a loop, mark it as one that should
     // also use the full code generator.
     FunctionLiteral* lit = fun->AsFunctionLiteral();
     if (lit != NULL &&
         lit->name()->Equals(Heap::empty_string()) &&
@@ skipping 1596 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64