Messages in this thread | | | Date | Thu, 31 Oct 2002 10:08:55 -0700 | From | Matt Porter <> | Subject | Re: CONFIG_TINY |
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On Thu, Oct 31, 2002 at 07:33:01AM -0700, Tom Rini wrote: > On Thu, Oct 31, 2002 at 12:33:10AM -0500, Mark Mielke wrote: > > On Wed, Oct 30, 2002 at 06:10:02PM -0700, Tom Rini wrote: > > > On Thu, Oct 31, 2002 at 01:53:14AM +0100, Adrian Bunk wrote: > > > > could you try to use "-Os" instead of "-O2" as gcc optimization option > > > > when CONFIG_TINY is enabled? Something like the following (completely > > > > untested) patch: > > > -Os can produce larger binaries, keep in mind. If we're going to go > > > this route, how about something generally useful, and allow for general > > > optimization level / additional CFLAGS to be added. > > > > Sure CFLAGS should be configurable, but CONFIG_TINY should always prefer > > -Os over -O2. From 'man gcc': > > > > -Os Optimize for size. -Os enables all -O2 optimizations that do not > > typically increase code size. It also performs further optimiza- > > tions designed to reduce code size. > > > > If gcc regularly generates larger code with -Os the answer is to talk to > > the gcc people, not to avoid using -Os... > > It's not that it does regularly, it's that it can, and if it does, it's > not really a gcc bug from what I recall. So I don't think CONFIG_TINY > should prefer -Os over -O2 but instead we should just ask the user what > level of optimization they want. Remember, one of the real important > parts of embedded systems is flexibility.
Thank you. This is exactly why in the last CONFIG_TINY thread I made it clear that a one-size-fits-all option is not all that helpful for serious embedded systems designers.
Collecting these parameters in a single tweaks.h file and perhaps using things like CONFIG_TINY, CONFIG_DESKTOP, CONFIG_FOO as profile selectors into tweaks.h would be a lot more effective. His collection of (hopefully) size-optimizing tweaks can all be selected via CONFIG_TINY, but have them collected at a single point like tweaks.h such that they can be individually modified by an end system integrator.
Regards, -- Matt Porter porter@cox.net This is Linux Country. On a quiet night, you can hear Windows reboot. - 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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