https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64442
Colin Pitrat <colin.pitrat+gcc at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #4 from Colin Pitrat <colin.pitrat+gcc at gmail dot com> --- OK thank you, sorry for the bothering ! In the mean time I also discovered -Og that appeared in gcc 4.8, that provides optimization compatible with debugging and that have the same behavior. This allows me to have the same result with the release and the debug build, which is what was the issue for me. I'm still surprised by the fact that -Og or -O1 seems to be more than just the list of -f flags it activates, as providing only them doesn't trigger this same behaviour. I couldn't find another responsible flag in the difference I found in the output of --help=warnings,target,params,c or common Closing this bug as invalid. Regards, Colin