Re:
I think tree-ssa-loop-ivopts is simply
asking for the wrong thing, and needs to be changed. As I say,
Sandra had some fixes in this area.
This patch:
http://gcc.gnu.org/ml/gcc-patches/2012-06/msg00319.html
Sadly, that patch has fallen off the bottom of my priority list (some
legal wrangling halted all work on the Hexagon port that was the
motivating example for it), and meanwhile it's become bit-rotten due to
Bill Schmidt's work that touched on the ivopts code as well. If someone
else would like to "adopt" this patch, please do!
I agree that it is just plain dumb for ivopts to be trying to precompute
address costs for modes that are not even valid.
-Sandra
