------- Comment #19 from rguenth at gcc dot gnu dot org 2006-04-10 11:56 ------- So it is indeed chicken and egg ;) load-PRE does not PRE the loads if the loop is not in do-while form, and we won't hoist the loop header copies until the loads are PREd. As to comment #13, if we are able to "clean" the two innermost loops of a nest that is already a good improvement. Though from all the experiments it looks like it is advisable to write do-while loops with hoisted loop header copies manually rather than for loops.
-- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23855
