Previous studies have shown that object-oriented programs have differentexecution characteristics than procedural programs, and that specialobject-oriented hardware can improve performance. The results of these studiesmay no longer hold because compiler optimizations can remove a large fractionof the differences. Our measurements show that SELF programs are more similarto C programs than are C++ programs, even though SELF is much more radicallyobject-oriented than C++ and thus should differ much more from C.Furthermore, the benefit of tagged arithmetic instructions in the SPARCarchitecture (originally motivated by Smalltalk and Lisp implementations)appears to be small. Also, special hardware could hardly reduce messagedispatch overhead since dispatch sequences are already very short. Two generichardware features, instruction cache size and data cache write policy, have amuch greater impact on performance.