Left out a paragraph that's now gone to the cut and paste gremlin, so i'll paraphrase:
Part of the point about the pix_gain illustration is not that altivec or my scalar code kick ass, but that the original pix_gain code could actually run faster than my changes on a different platform. There should be a fair amount of testing when these things are changed, for compatibility, stability, and performance. It's not possible for each developer to know the ins and outs of tweaking each and every platform and compiler, so some collaboration is necessary on the shape of the code.
Anyway I really just wanted to open up a discussion about making GEM really fly on all platforms. ;)
On a somewhat related note: Is there someone building a Windows version of the CVS? I have a win2k box with pre-CVS GEM and no compiler, and would like to check out how the CVS version runs on it.
best cgc