From -8616922605240763871 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,206db806b836bf67 X-Google-Attributes: gidf78e5,public From: Pierre Baillargeon Subject: Re: Pointers to incomplete type Date: 1998/01/26 Message-ID: <34CCAEC5.2AD2519E@jazzmail.com>#1/1 X-Deja-AN: 319529768 References: <69osom$jf3@examiner.concentric.net> <6a0a4g$rf1@shell.magma.ca> <6a0t54$k83@examiner.concentric.net> <6a3be4$6qu$1@uuneo.neosoft.com> <6a7fli$gtj@examiner.concentric.net> X-Original-Date: Mon, 26 Jan 1998 10:41:58 -0500 Organization: Bell Network Solutions X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBVAwUBNM05Tky4NqrwXLNJAQEbnQH8C1txTixsLHTl0A/75vreAlLMHrvjLGzX boHfLrQXkvVYJQ6Mqj+hEwHcN+h8CXJ4/7VxucZnfvjIrOD+uXQYZg== =Oh5a Newsgroups: comp.std.c++ Originator: austern@isolde.mti.sgi.com Bradd W. Szonye wrote:[...] > This leads me to ask another question: I've heard that the traditional > cfront vptr-in-object memory model is not the only possible choice for C++, > but what are some alternatives with comparable performance? I have read report on super-optimizing experimental compilers, and they do use other techniques. It was called Vortex. It uses global-program class analysis to determine the number of implementations for a particular vtable or virtual function. It then either generate: a non-virtual function (one impl.), in-code switch statement (few impl.), a cache of more probable vtable results (many impl., with test-run feedback). The gain of putting in-code tests is to avoid loading a different page in memory where the vtable is located and it allows optimizations to be done accross calls (if only for the look-ahead instruction of many RISC jump). --- [ comp.std.c++ is moderated. To submit articles: Try just posting with your newsreader. If that fails, use mailto:std-c++@ncar.ucar.edu comp.std.c++ FAQ: http://reality.sgi.com/austern/std-c++/faq.html Moderation policy: http://reality.sgi.com/austern/std-c++/policy.html Comments? mailto:std-c++-request@ncar.ucar.edu ]