Date: Wed, 15 May 2002 09:55:44 +0200 From: Thomas Pornin <pornin@bolet.org> To: alpha@FreeBSD.org Subject: Re: Alpha CPU Performance vs i386 Message-ID: <20020515095544.A50576@gnah.bolet.org> In-Reply-To: <20020515093259.A50064@gnah.bolet.org>; from pornin@bolet.org on Wed, May 15, 2002 at 09:33:00AM %2B0200 References: <20020514201923.GK37326@Area51.DK> <20020514222344.A2915@freebie.xs4all.nl> <20020515161627.O18023@gsmx07.alcatel.com.au> <20020515093259.A50064@gnah.bolet.org>
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On Wed, May 15, 2002 at 09:33:00AM +0200, Thomas Pornin wrote: > I have used as my main working machine a Miata for three years (under > Linux first, then FreeBSD) and I came to the following conclusions: I forgot one point which seems to me to be of some importance: Alpha are slow at compiling C code. It is not specific to the Alpha architecture, it is just that gcc is slow. I have been told that the register allocator in gcc uses an algorithm which is exponential in the number of available registers. A PC has 6 or 7 generic-purpose registers, an Alpha has 31... The Compaq compiler is slow also, but I think it is general sloppiness that is often seen in big software from big companies. It produces really good code, though (I often observed a 30% improvement in speed over gcc on generic integer code). I have been looking for a decent, fast C compiler on the Alpha, and I found none. Lcc is completely buggy on the Alpha/OSF, and is anyway not up-to-date with regards to C99. TenDRA was not fast, and seemed to be quite peckish about its own interpretation of what is portable. Maybe I overlooked something ? --Thomas Pornin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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