Re: 2 changes in the CVS

[Karim BELABAS <Karim.Belabas@math.u-psud.fr>]

On Fri, 6 Dec 2002, Igor Schein wrote:
> On Fri, Dec 06, 2002 at 03:12:55PM +0100, Karim BELABAS wrote:
>> On Fri, 6 Dec 2002, Bill Allombert wrote:
>>> I have commited two change to the CVS.
>>
>> While we are at it: I have enabled Karatsuba multiplication for t_REAL (code
>> has been here for at least 2 years, but was unused). It is not properly tuned
>> yet, but at least it seems to give correct (and correctly rounded) results.
>
> My testsuite runs about 10% slower now.  I'll wait 'til it's tuned.
> Or will a slowdown for default precision unavoidable?

I've included KARATSUBA_MULR_LIMIT to the list of defines computed by the
'tune' utility [ make tune && tune ]. It turns out that full product using
Karatsuba mulii() becomes consistently faster than default mulrr() for
arguments having about 300 words (!) on my machine.
[ should really implement Mulders/Hanrot-Zimmermann short products... ]

Back to normalcy ?

    Karim.
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Karim Belabas                    Tel: (+33) (0)1 69 15 57 48
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