Re: non trivial constant folding

On 5 Jan 2001, Mickaël Pointier wrote:


> My problem is that I do not manage to find a clean solution
> to optimise this:
>
> eval(1+var+1)
>
> [I've seen compilers that do that. With associative operators like +
> they combine all of the operands of a set of cascaded operators into
> a list or array, then sort that array to get the constants together.
> -John]


You will find several methods to convert expressions to a canonical form,
which includes your example as a special case, in Chapter 6
"Converting to a Canonical Form" in
Automatic Algorithm Recognition and Replacement:
A New Approach to Program Optimization,
R. Metzger and Z. Wen, MIT Press, 2000.


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