https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63445
--- Comment #5 from rguenther at suse dot de <rguenther at suse dot de> --- On Tue, 7 Oct 2014, manu at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63445 > > --- Comment #4 from Manuel López-Ibáñez <manu at gcc dot gnu.org> --- > > i_15 could be negative and thus j_9 - i_15 could well overflow the input > > range at the +INF side. (i_15 is [-INF, j_5(D) + -1]) > > Actually, this is a very good point. There is indeed a potential integer > overflow in the original code. Thus, the warning seems valid. > > Perhaps the warning message could say that the problem is that "j - i" can > overflow if i is negative. Sure - but we warn about the comparison against zero which doesn't behave differently if overflow wraps or is undefined.
