| 1 |
On Mon, 14 Jul 2003 02:14:32 -0400 |
| 2 |
Mike Frysinger <vapier@g.o> wrote: |
| 3 |
|
| 4 |
> the bug can be found at http://bugs.gentoo.org/show_bug.cgi?id=24379 |
| 5 |
> i just want to know if anyone out there has had *success* with this flag |
| 6 |
> ... |
| 7 |
|
| 8 |
I've had much success with this flag, after long trying times with learning |
| 9 |
what flags you can get away with in regards to the different packages. I |
| 10 |
first started with- |
| 11 |
-O3 -march=k6-2 -pipe -funroll-loops -fomit-frame-pointer (continuing list |
| 12 |
of -f functions) |
| 13 |
and whittled down to- |
| 14 |
-O2 -march=k6-2 -pipe -fomit-frame-pointer with these observations- |
| 15 |
|
| 16 |
-O3 and -funroll-loops work together if not appended with -fPIC or any other |
| 17 |
-*PIC option by the source. |
| 18 |
-O3 and -funroll-loops will build compression packages (bzip2,jpeg,etc) but |
| 19 |
will not allow them to execute correctly. |
| 20 |
Bottom line is that since gcc 3.x, the difference between -O3 and -O2 on |
| 21 |
k6's speedwise is imperceptible to the end user, and I advise really staying |
| 22 |
away from -O3 and excessive -f* functions, especially in the loop dept.:) |
| 23 |
-- |
| 24 |
Chuck Brewer |
| 25 |
Registered Linux User #284015 |
| 26 |
Get my gpg public key at pgp.mit.edu!! Encrypted e-mail preferred. |
Archives