On Sat, 14 Oct 2000, Martin Husemann wrote:

: > Anyone know where in the source tree to set optimization flags for the
: > c compiler? I would like to try and make the world with -06 if possible.
: 
: You can change /usr/share/mk/sys.mk or set /etc/mk.conf.
: 
: But beware: I used to build the world on i386 with -O6 for some time (just
: to test this) and found at least two gotchas: the bootblocks won't work
: and there were optimization errors in the softdep code, leading to random
: crashes under heavy file system load. Going back to -O2 imediately fixed
: this.

There are some optimization errors at levels above -O2 in the in-tree egcs
1.1.2 that make using above -O2 a risky operation (as is documented in the
gcc docs).  If you want a smidgin faster binaries, use optimization flags
that reflect your target CPU:  -mpentiumpro or -m486 with -O2.

Note that -O[456] is equivalent to -O3 in the egcs 1.1.x that is in-tree.  
I don't know offhand whether gcc 2.95.2, which I'm working to switch to in
-current, has differences between -O[3456].

-- 
-- Todd Vierling <tv@wasabisystems.com>  *  http://www.wasabisystems.com/
-- Speed, stability, security, and support.  Wasabi NetBSD:  Run with it.