32 bit left rotates where n > 1: a hack

Dan Ingalls DanI at wdi.disney.com
Mon Jan 26 17:34:19 UTC 1998


"Christopher Oliver" <oliver at fritz.co.traverse.com> wrote...

>At this time, I'm seeking the cheapest non-VM hack for addition
>of from two to four 32 bit Integers.  Even with my shift hack,
>hash code seems painfully slow.  I'd like to get a RIPEMD-160
>compress to around 16ms per block on a 133MHz Pentium.

You might be surprized how well you can do using Floats.  David Smith rewrote the Random number generator to work this way and it ran about 5 times faster than when it was tickling the LargeInt code.  Check it out.  ]I have often thought of implementing bit-logic methods for Floats so as to be able to discard all the LargeInteger code in very small Squeaks].

	- Dan





More information about the Squeak-dev mailing list