I'm playing around with optimizing compiled packages to run fine on Ångström, but the question isn't really Ångström-specific.
I've seen on Meanie's blog on building Firefox natively that he used the -O4 option in CFLAGS.
I've looked but not found anything substantive on this flag. One Finnish page on the web states that if -On has n higher than 3, then the flag is automatically interpreted as -O3. Is this so? Or is there a difference between these?