http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58143
--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Because the bug is in lim, so hacking around it in other parts of the compiler and removing desirable optimizations just to mitigate the bug is not the right way to fix it. Either lim shouldn't move the expressions if they are conditional in the loop body and might trigger undefined behavior in the place where it has been moved to while it might not trigger undefined behavior originally, or lim should transform them into expressions that won't trigger undefined behavior while moving them if it can't prove this will not happen (in this case that would mean performing the arithmetics in a type that doesn't have undefined behavior on overflow).
