X-POP3-Rcpt: mlehmann AT universe DOT sgh-net DOT de 24 Jan 1998 00:27:17 +0100 (CET) From: Ronald Wahl X-Sender: rwa AT goliath DOT csn DOT tu-chemnitz DOT de To: Steve Bergman cc: beastium-list AT Desk DOT nl Subject: Re: Status of AMD K6 Support In-Reply-To: <34C92380.B2C424BC@netplus.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: Marc Lehmann Status: RO Content-Length: 1746 Lines: 39 On Fri, 23 Jan 1998, Steve Bergman wrote: > What is the current status of AMD K6 optimization in egcs/pgcc? > Information on this subject seems virtually nonexistent. What I have > gleaned about it amounts to this recommendation: > > gcc -O6 -mamdk6 -fno-software-pipe -fno-swap-for-agi > -fno-schedule-stack-reg-insns -fno-exceptions The options no-software-pipe, no-swap-for-agi and no-schedule-stack-reg-insns are now included in -mamdk6. > I am running redhat 5.0 (glibc2) and am specifically interested in > optimizing Mesa, which is an OPENGL compatible graphics library. It is > fpu intensive and I notice that there are some recommendations for fpu > intensive programs in the FAQ. I have compiled the library in the past > with "-O6 -mamdk6" and found it to be slightly slower than standard gcc > 2.7.*. Does anyone have any recommendations? Try -funroll-loops or -funroll-all-loops. This may give a speedup or a slowdown. Maybe you should also check the latest snapshots. But note: The code generated by this two options is still broken in some cases. What you also could try is to optimize the assembler routines in Mesa. Try to minimize the fpu instructions (e.g. remove the fxch instructions and adapt the code) and use integer code in parallel with fpu code. Further more recommendations you will find in the optimization guide that is located here: http://www.amd.com/K6/k6docs. .... but the best optimization you will get with a 3D accelerator by 3dfx since these chips are supported by Mesa. ron -- \ Ronald Wahl --- rwa AT informatik DOT tu-chemnitz DOT de \ \ WWW: http://www.tu-chemnitz.de/~row \ \ Talk: rwa AT goliath DOT csn DOT tu-chemnitz DOT de \ \ PGP key available by finger to my email address \