Author: Severi Salminen
Date: 14:16:51 11/26/00
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>The original reason was that I did this long before __int64 became available. > >But still, even though VC++ now supports __int64, it doesn't do it extremely >well. Many of the operations are subroutine calls, while my BitBoard class >inlines all its functions. Can you say in what situations it calls a subroutine? I'm using __int64 integers and I'd like to know if there are some bottlenecks around. I'm, however, using inline assembler in crucial points (finding the index of a bit and population counting). >Also, you can often shortcut an operation if you can decide the outcome after 32 >bits. When you AND two bitmaps to see if they overlap, and the first halves >does, you don't have to test the second half. I believe that makeing one AND and testing the result could be even slower or at least equally fast than making two ANDs without any testing. But this is just generalization and every case is individual. In your example testing after the first AND is faster if the first AND is succesful. Have you tried how VC6++ would deal your example with __int64? I'd guess it would not test the second part if the first test is succesful. Severi
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