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Re: Performance on an alpha 21164 using egcs 1.0.3 ???
- To: peter dot biechele at physik dot uni-freiburg dot de
- Subject: Re: Performance on an alpha 21164 using egcs 1.0.3 ???
- From: Alan Lehotsky <lehotsky at sunspot dot tiac dot net>
- Date: Wed, 30 Dec 1998 14:59:55 -0500 (EST)
- CC: egcs at egcs dot cygnus dot com
I would bet that SQRT on the Alpha is NOT done in the FPU, but via
a software implementation. The x86 architecture has a FSQRT
instruction that is probably inlined.
>
> We just bought DEC Alpha Computers and installed Linux Red-Hat 5.2 on them. The
> Compiler coming with it are EGCS -1.0.3 !
>
> I have written a small program which consist of just two nested loops and a
> square root calculation. I compiled this program under:
>
> DEC Alpha 21164 600 / Linux / egcs 1.0.3: 35 seconds
> Intel PII 450 / Linux (Debian) / egcs 1.0.3: 6 seconds
> Intel PII 450 / Linux (Debian) / gcc 2.7.2 : 12 seconds
>
> How is this possible !!???????????
>
> The DEC Alpha should be at least the same performance !!!
>