On Jun 11, 2007, at 9:38 AM, Jochen Küpper wrote:
On 11.06.2007, at 11:02, Pierre Queinnec wrote:IIRC Apple recommends -Os, not -O2.Why? Where is that documented?
I've seen it elsewhere, but in this link, the "Fastest, smallest" Xcode setting corresponds to -Os
http://developer.apple.com/documentation/Performance/Conceptual/ CodeFootprint/Articles/CompilerOptions.html
There's also discussion here: http://developer.apple.com/tools/gcc_overview.html Which mentions -"When in doubt, it may be better to optimize for size, since smaller code may execute relatively faster. For example, large functions or loops containing data access patterns that do not exhibit a strong locality of reference may not fit into a processor's cache lines, which can lead to cache misses and subsequent fetches from memory. Smaller functions or loops with local data access stand a better chance of fitting in a given cache line and requiring fewer memory accesses."
-- Daniel J. Luke +========================================================+ | *---------------- [EMAIL PROTECTED] ----------------* | | *-------------- http://www.geeklair.net -------------* | +========================================================+ | Opinions expressed are mine and do not necessarily | | reflect the opinions of my employer. | +========================================================+
PGP.sig
Description: This is a digitally signed message part
_______________________________________________ macports-users mailing list [email protected] http://lists.macosforge.org/mailman/listinfo/macports-users
