------- Comment #5 from amylaar at gcc dot gnu dot org 2009-07-16 00:11 ------- (In reply to comment #3) > Hi Steven, > > Maybe I'm missing something, but what do patches talking about > SMALL_REGISTER_CLASSES have to do with this issue? For ARM, the registers > involved are general purpose and ! SMALL_REGISTER_CLASSES. There's about 14 > of > them available, and these PHIs want a virtually unbounded number of > registers. > And we are not optimizing for size (-O3). So I can't see how your patch is > going to help. > > Don't get me wrong, I'm happy to close it again if they will :-) But I don't > think either of the checks in want_to_pre_p will apply.
Look at comment #14. My patch attempts to do a cost-benefit analysis of phi-node (with implied copies) insertion versus the saved arithmetic. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40768
