Re: [ACPI] ACPI mentioned on lwn.net/kernel

[Andrey Panin <pazke@orbita1.ru>]

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On Tue, Jan 29, 2002 at 02:14:32PM -0500, Mark Hahn wrote:
> > 	- what stop us from using -mregparm=3 gcc switch ?
> 
> I dimly recall that it can generage bad code, perhaps only
> on old compilers.

Bad code, hmm ... slow code or wrong code ?
IIRC gcc 2.95.3 declared as minimal requirement for kernel compilation,
so may be it's not an issue anymore ?

> 
> > 	- same with -Os -malign-loops=1 -malign-jumps=1 ?
> 
> 2 is probably always the lowest you should go, and indeed,
> I think that's all the compiler permits.
>

gcc (at least 2.95.2) permits 1, but i didn't check generated code.

> > 	- any tool to measure perfomance gain/penalty of above ?
> 
> lmbench.  it has to be a microbenchmark to measure this sort of thing,
> though a sanity check (kernel compile) would also be useful.

Thanks, i'll test these issues this weekend. 

Best regards.

-- 
Andrey Panin            | Embedded systems software engineer
pazke@orbita1.ru        | PGP key: wwwkeys.eu.pgp.net

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