Re: gcc300 benchmarks slower than gcc295.3?

["RenE J.V. Bertin" <rjvbertin at hotmail dot com>]

>
>While 3.0 shouldn't give worse results than 2.95.3, note that stack
>alignment only works as well as your libraries and startup modules are
>aligned.  Most installed libc's aren't, and hence, no matter how well
>3.0 maintains alignment, chances are your code isn't aligned.
>
>To fix this you have to rebuild libc with your preferred alignment

	And find nothing works after reboot? :)

>options (although not with -malign-double!), and AFAIK, 3.0 still
>won't build glibc 2.2.3.  (Anybody have an update on this?)

I am not sure whether this is the reason for the phenomenon I observe. 
Firstly, as far as I have verified, the dhrystone benchmark programmes I 
used (attached) don't do calls to library functions in the test routines 
(strcmp should be inlined). Secondly, why would this give a different 
penalty to gcc300 vs gc295.3?? I'd expect them to be penalised equally - 
unless the default for e.g. -mpreferred-stack-boundary is different!

Another possibility is that gcc3 needs a more recent libc/kernel combination 
(1.2.10/2.2.13-7mdk) than I am using. I'd hope not - I'd hate to have to 
update my OS more than once every 2 years! :)

Attachments:
dry.c : integer dhrystones benchmark
fldry.c: floating point version of dry.c (I compiled with -Dextended=double)

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dry.c

fldry.c