Messages in this thread | | | Date | Sun, 19 Oct 2003 08:40:50 -0700 | From | "Martin J. Bligh" <> | Subject | Re: [2.6 patch] add a config option for -Os compilation |
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>> Martin was ironically talking about people who are ignorant of machines >> with _huge_ caches. >> > > Oh. Sorry. Probably I need to work on my English bit more. > >> I the context of this thread he wanted to vote for making -Os >> conditionally and not unconditionally enabled by telling that he knows >> of situations where -O2 produces faster code. > > Absolutely. > High-end toys, after all, optimized to handle this. > > IMHO this should be settled on per-target basis: embedded system - -Os; servers - -O2; desktops - -O3 ;) So instead of CONFIG_EMBEDDED better to have CONFIG_TARGET=[desktop|server|embedded]. > > Inroducing one more variable into builds - is really painful. I was hit by gcc miscompiles and internal errors not once (especially with -O[23]). Tracking down this kind of issues would be made more problematic. > > P.S. I'm really sorry for my rude response.
;-) No problem.
But if someone with a small cache would actually *measure* the damned thing, I'd be more impressed ... I've never seen that, but perhaps I just missed it.
Point is the same either way though ... we shouldn't unconditionally optimise for *anyone's* system. If it's faster on all systems that anyone can be bothered to measure, great. If it's faster on some, and slower on others, a config option seems more appropriate, defaulting to the majority of users.
M.
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