------- Comment #6 from rakdver at gcc dot gnu dot org 2005-10-09 19:36 ------- With the recent changes to scev analysis that ensure that signed chrecs do not wrap (assuming -fno-wrapv), it is fairly easy to get tree level # of iterations analysis to use this fact, see the attached patch.
This does not directly help doloop opts that work on rtl, though. There are two possible solutions: 1) Rewrite the loop on tree level to a form that is easier to analyse, e.g., for (i = 0; i != n + 1; i++) 2) Somehow pass the information that the loop is not infinite (or even that its control iv does not wrap) to rtl. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18527
