------- Additional Comments From hubicka at ucw dot cz 2005-08-01 15:14 ------- Subject: Re: [4.1 Regression] Dominator opts slows down bresenham line drawing by roughly 20%
One problem is that DOM manages to convert a += 1; if (....) a += 10; to a1 = a + 1 if (....) a1 = a + 11 a1 = a hence the extra move even on 3-address architectures. There are two such additions done in parallel so we won't get cmove. We either need to go the all way around and produce if-then-else and save one instruction or avoid this transformation as it is dificult to undo. Honza -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23181