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Re: Multiplications on Pentium 4

> Frank Klemm <pfk@fuchs.offl.uni-jena.de> writes:
> 
>   The Pentim 4 is so different from all other CPUs so I must write a special
>   Code Choice Generator. Some Examples:
> 
> I don't know what a Code Choice Generator is, but I know that
> multiply-by-constant code generation is controlled by the *COSTS
> macros.  If you set these up properly for Pentium 4, you should get
> code sequences that use fewer shifts and more adds.
Frank wrote3 his own code to generate various sequences and compare them.
His code produces better results in some cases, as it is aware of some details
gcc generator isn't.

Honza
> 
> (It isn't going to become perfect since this code understands nothing
> about scheduling.)
> 
> -- 
> Torbjörn
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