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|    comp.lang.asm.x86    |    Ahh, the lost art of x86 assembly    |    4,675 messages    |
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|    Message 3,798 of 4,675    |
|    James Harris to All    |
|    Fast conversion to a boolean of 0 or 1    |
|    06 Mar 19 19:37:35    |
      From: james.harris.1@nospicedham.gmail.com              A small programming challenge if you are interested, just for fun.              Say we want any value other than 0 in EAX to be reduced to 1 - e.g. so       that if non-zero means true but we want true to be 1.              Is there a faster solution than the naive               cmp eax, 0        je done        mov eax, 1        done:              Naturally, the speed of that will depend on how predictable the input       values are. Taking into account the usual suspect characteristics of x86       CPUs is there a generally faster solution?              I can think of three bit-twiddling ways but I'm not sure they would be       faster than the above. In fact, I think they might be slower. In any       case I'd be interested to see what others think. I suspect some of you       may already have a preferred solution.              So, any suggestions?                     --       James Harris              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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