Formal annotating Code for Optimizations?

[JAnderson]

Manfred_Nowak wrote:
> Example:
> If two actions `a1',`a2' are based on a binary decision `b' then on a 
> pure logical level one can code:
> 
>   if( b)
>     a1.do; // actions have `do'- and `undo'-methods
>   else
>     a2.do; 
> 
> But if one knows, that the probability of `b' to be `true' is much 
> greater than .5, then in order to use the precomputing capabilities 
> of the CPU one would probably like to code:
> 
>   a1.do;
>   if( !b){
>     a1.undo;
>     a2.do;
>   }    
>     
> The other case requires similar code.
> 
> In this latter code the abstraction of a simple binary decision seems 
> to be less obvious, which seems to be bad for maintenance.
> 
> Of course one can annotate with comments. But since comments can be 
> hints for defencies in the language, the question rises whether one 
> should formalize this:
> 
>   if( b)note( p(b)>.8)
>     a1.do;
>     undo a1.undo;
>   else
>     a2;
>     undo a2.undo;
> 
> -manfred

MSVC++ 2005 has this profile that you can run on the code and then it 
will use that to optimize the code to use the most common paths.  I'm 
not sure if it also optimizes IF statements.  I know it optimizes 
functions layout to be more cache friendly.

-Joel