Messages in this thread | | | Date | Thu, 20 Dec 2001 01:10:09 +0100 | From | Erik Mouw <> | Subject | Re: gcc 3.0.2/kernel details (-O issue) |
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On Wed, Dec 19, 2001 at 03:03:30PM -0500, Robert Love wrote: > On Wed, 2001-12-19 at 14:39, Martin Devera wrote: > > It is interesting that 2.2 can be done with -O. Also I'd expect > > errors during compilation and not silent crash... > > Well, you certainly won't get errors, because compiler optimizations > shouldn't change expected syntax.
It doesn't change syntax, but anything lower than -O1 simply doesn't inline functions with an "inline" attribute. The result is that the inline functions in header files won't get inlined and the compiler will complain about missing functions at link time (or module insert time).
I'm actually surprised that 2.2 can be compiled with -O, AFAIK linux-2.2 also has a lot of inline functions in headers. I know from experience that -Os works for 2.4 kernels on ARM, I haven't tested it with 2.2 or x86.
Erik
-- J.A.K. (Erik) Mouw, Information and Communication Theory Group, Faculty of Information Technology and Systems, Delft University of Technology, PO BOX 5031, 2600 GA Delft, The Netherlands Phone: +31-15-2783635 Fax: +31-15-2781843 Email: J.A.K.Mouw@its.tudelft.nl WWW: http://www-ict.its.tudelft.nl/~erik/ - 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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