[EGCS] Re: min/max macros

Marc Lehmann pcg@goof.com
Thu Dec 11 17:57:00 GMT 1997


> > #define max(a,b)	(((a) > (b)) ? (a) : (b))
> > #define min(a,b)	(((a) < (b)) ? (a) : (b))
> 
> That is a big no-no: Absolutely no performance benefits with any decent
> compiler but nasty side effects.

so egcs isn't a decent compiler?

for example, the macro-max(2,3) will be evaluated at compile time,
while the function-max(2,3) won't...

this get's even worse on things like:

int mult(int a, int b) { return a*b; };

mult(a,3) will result in an "imul 3" on x86... definitely
slower than a lea, for example.

      -----==-                                              |
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      ---==---(_)__  __ ____  __       Marc Lehmann       +--
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    The choice of a GNU generation                        |
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