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SubjectRe: [patch] string-486.h modified
Jamie Lokier wrote:
>
> Alan Cox wrote:
> > > Alan, can you send me again the list of CPUs you think
> > > is worth using 486 string routines.
> > > Sorry, i lost your previous mail.
> >
> > I suspect it is
> >
> > 486
> > K5
> > IDT Winchip
> > Rise
> > NexGen
>
> Take a look at
> http://now.cs.berkeley.edu/Td/bcopy.html


Nice page, thank you.


> Speed increases by 50% for unrolled string copies on their P5s. Sure
> they're old, but so are 486s :-)
>
> Of course you do _not_ want to inline a long string copy routine.
> There should probably be a arch/i386/lib/string-486.c.


These routines are often used and one of the goals was reducing code
size. That's why for generic case i used as few instructions as
possible,
while for optimized one i made some speedups with the cost of few
instructions more.

I don't see the point of string-486.c - string-486.h is a replacement
of string.h for i[45]86 machines so let stay in include directory.



best,
Petkan
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