On Wed, May 4, 2011 at 07:44, Richard Kenner <ken...@vlsi1.ultra.nyu.edu> wrote: >> That's what we should phase out. The eventual aim should be for (a) >> folding on GIMPLE (gimple-fold etc. - working with SSA not combined trees) >> as an optimization and (b) folding done by front ends only when required >> for language semantics (e.g. constant expressions). > > Why? Isn't it always better to optimize as early as you can when it's > easy? Why keep unfolded constants around at all?
There are pros and cons about early optimization, actually. Generating extremely optimized IL very early can actually tie up subsequent passes. For instance, loop unrolling and vectorization. There are others in the literature. Diego.
