Message 73624 - Python tracker

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In-reply-to
Author	pernici
Recipients	pernici
Date	2008年09月23日.10:25:57
SpamBayes Score	0.0009886356
Marked as misclassified	No
Message-id	<1222165559.78.0.447355238601.issue3944@psf.upfronthosting.co.za>

Content
In this patch x_mul(a, b) uses fewer bit operations for a != b, asymptotically half of them. On the three computers I tried the speed-up is around 5% for size=4 and it increases up to 45-60% just below the Karatsuba cutoff, then it decreases a bit after this cutoff (on one computer the speed-up is only 16% after KARATSUBA_CUTOFF=70, but raising the cutoff to 140, for which with the current code the multiplication is also faster, the speed-up is 45%).

Content

In this patch x_mul(a, b) uses fewer bit operations for a != b,
asymptotically half of them.
On the three computers I tried the speed-up is around 5% for size=4
and it increases up to 45-60% just below the Karatsuba cutoff,
then it decreases a bit after this cutoff (on one computer the speed-up
is only 16% after KARATSUBA_CUTOFF=70, but raising the cutoff to 140,
for which with the current code the multiplication is also faster,
the speed-up is 45%).

History
Date	User	Action	Args
2008年09月23日 10:25:59	pernici	set	recipients: + pernici
2008年09月23日 10:25:59	pernici	set	messageid: <1222165559.78.0.447355238601.issue3944@psf.upfronthosting.co.za>
2008年09月23日 10:25:58	pernici	link	issue3944 messages
2008年09月23日 10:25:57	pernici	create

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