Deja News Toolbar Search over 20,000 high-tech jobs Click here for over 20,000 high-tech jobs message/thread Message 276 of 6 for search * help Re: What's Diabolo? (and who's Po Ching?) Author: John/Lori Date: 1999/02/23 Forum: comp.sys.cbm sponsored by: eBay more headers author posting history post reply _________________________________________________________________ > Yep, that's what the instruction collapse portion of the code does. :-) > Almost exactly, even. > Do you do any other optimizations? I think the next one that's usually given is substituting an increment for addition of an (immediate) one > Interesting. How does that help multiplication? By reducing it to bit shifts, > or what, exactly? Basically, yes with the example I gave, OO1111100 as the multiplier, you would substitute one addition and one subtraction for five additions take the multipier to be 000011111 (just to make it a little more obvious) in decimal 31=32-1 so rather than (the multiplicand is y) 16*y+8*y+4*y+2*y+1*y you have 32*y-1*y There's also a variation that propogates a carry across single 0's (I think that's Johnson's algorithm but I don't really remember) _________________________________________________________________ view for bookmarking text only mail this message to a friend post reply << prev · next >> subscribe to comp.sys.cbm SPONSORED LINKS Yellow Pages · Bid on Bargains · Shopping · Free Stuff · 5¢ long distance AutoConnect · Trade with Datek · Auctions & Classifieds · GET IT NOW @ NECX Home · Communities · My Deja News · Power Search · Post About Deja News · Ad Info · Our Advertisers ____________________________________________________ Copyright © 1995-99 Deja News, Inc. All rights reserved. Conditions of use · Site privacy statement reviewed by TRUSTe