shift bit & performance?

Mike Eggleston mikee at mikee.ath.cx
Tue Oct 21 16:32:07 EDT 2003


On Tue, 21 Oct 2003, Eduardo Cesar Cabrera Flores wrote:

> 
> 
> Hi, 
> 
> sometime ago, somebody sent an info about performance working with "<<" & 
> ">>" doing shift bits instead of using "*" or "/"
>  Could anybody help me about it?

The operations << and >> are closer to assembler operations
for integer values than * and /. If using * or / there are
many assembler instructions to compute the new values. When
using power of 2s for * or / then << and >> are much faster.

Mike
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