Messages in this thread | | | Date | Thu, 31 Oct 2002 10:24:05 -0700 | From | Tom Rini <> | Subject | Re: CONFIG_TINY |
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On Thu, Oct 31, 2002 at 12:12:40PM -0500, Mark Mielke wrote:
> On Thu, Oct 31, 2002 at 10:04:20AM -0700, Tom Rini wrote: > > On Thu, Oct 31, 2002 at 11:51:13AM -0500, Mark Mielke wrote: > > > Or specified more clearly: If the compiler optimization flag is > > > configurable, choosing CONFIG_TINY should default the optimization flag > > > to -Os before it defaults the optimization flag to -O2. > > You're still missing the point of flexibility remark. Changing the > > optimization level has nothing to do with CONFIG_TINY, and is a > > generally useful option, and should be done seperate from CONFIG_TINY. > > In fact people seem to be getting the wrong idea about CONFIG_TINY. We > > ... > > Please read it again... even if the optimization flag was > configurable, choosing CONFIG_TINY should *default* the optimization > flag to -Os before it defaults the optimization flag to -O2.
Yes, and I'm saying that CONFIG_TINY shouldn't exist. It should be CONFIG_FINE_TUNE (or so), to allow anyone to fine tune the optimization level. Changing optimization levels is a speed / size tradeoff (if it wasn't, there wouldn't be -O2 / -Os, they would do the same thing) which you cannot pick a sane default for.
> In the case where CONFIG_TINY is an option on its own, it means using -Os > instead of -O2. In the case where CONFIG_TINY is a template *not an option*, > the configurable "optimization flag" gets initialized to -Os. You could > still override -Os to be -O2 if you wanted to, or if CONFIG_TINY was not > specified, you could still override -O2 to be -Os... the default is -Os for > CONFIG_TINY.
You're still falling into the 'embedded must mean small!' trap. The template should default to the well tested -O2, not the less tested -Os.
-- Tom Rini (TR1265) http://gate.crashing.org/~trini/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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