Date: Mon, 13 Dec 2004 11:24:01 -0800 From: Marcel Moolenaar <marcel@xcllnt.net> To: Kirk Strauser <kirk@strauser.com> Cc: freebsd-alpha@freebsd.org Subject: Re: Safe (but quick) GCC settings on a PC64 with 5.3? Message-ID: <8B2E39C7-4D3C-11D9-BEF4-000D93C47836@xcllnt.net> In-Reply-To: <200412131300.34382.kirk@strauser.com> References: <200412131130.59807.kirk@strauser.com> <83229A4B-4D2E-11D9-9C15-000D93C47836@xcllnt.net> <200412131300.34382.kirk@strauser.com>
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On Dec 13, 2004, at 11:00 AM, Kirk Strauser wrote: > Out of curiosity, on my Athlon systems I can set "CPUTYPE=athlon-tbird" > in /etc/make.conf and it will automatically add "-march=athlon-tbird" > to my > system and ports builds. On my Alpha, though, it only adds > "-mcpu=ev45" > and not the expected "-march=ev45". Is this general to all Alphas, or > is > it because my ev45 is the bottom of the barrel instruction-wise so > there's > no instruction set optimization to be had? The interpretation of the -m options vary per platform. The meaning of -mcpu on alpha is the same as -march on i386: instruction selection and scheduling. -mtune is used to control instruction scheduling only and on i386 (at least) -mcpu is a deprecated synonym for that. It's a bit odd, but it looks like the GCC folks are trying to normalize things here. See also: http://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Submodel- Options.html#Submodel-Options -- Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net
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