------- Comment #12 from manu at gcc dot gnu dot org 2008-08-19 02:33 ------- The key difference is -ftree-vrp (which is enabled at -O2). With INIT=2, it is missing the obvious optimization that it detects with INIT=1. I wonder if this is expected (after all, it is value-RANGE-propagation) or there is a PR open about this.
Notice that any two consecutive integers trigger the optimization 0,1 but also 1,2 and thus remove the bogus uninitialized warning. -- manu at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|bogus uninitialized warning |bogus uninitialized warning |(loop representation) |(loop representation, VRP | |missed-optimization) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36296