Safe (but quick) GCC settings on a PC64 with 5.3?

[Marcel Moolenaar]

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 at xcllnt.net