https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78676
janus at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|[5/6/7 Regression] |[5/6/7 Regression] |Optimizer bug exposed by |Optimizer bug with |program with many bit |-ftree-vrp exposed by |operations |program with many bit | |operations --- Comment #6 from janus at gcc dot gnu.org --- (In reply to janus from comment #5) > gfortran 4.7 and 4.8 print at all optimization levels: > > -682598705 58 > 1741342173 32 > > That's also what 4.9 prints at -00 and -01. But then 4.9 (and upwards) print > at -O2 and -O3: > > -682598705 57 > 1741342172 32 > > The error goes away if I remove the loop (even though it occurs already for > i=1). The latter is printed by 4.9 also with "-O1 -ftree-vrp", but not with "-ftree-vrp" alone. In any case, this flag seems to be the culprit here.