Understanding Macro Pre-processor

Dave Korn dave.korn@artimi.com
Fri Sep 21 13:48:00 GMT 2007


On 20 September 2007 20:44, Bruno Moreira Guedes wrote:

> Bu I've been made some tests... By example... A macro:
> 
> #define mul(X,Y) (X*Y)
> 
> 
> It makes the processing faster... 

  Your test methodology is broken.

> But... Why executing that a milion of times is faster than using the
> simple a*b itself???

  It isn't.

> It really happens? 

  It doesn't.

> Why?

  Because you did one timing run when your system was under very heavy load of
background tasks and the other when it was under very light load, most likely.


    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....



More information about the Gcc-help mailing list