On Mit, 2012-02-01 at 21:04 +0000, Boehm, Hans wrote: [...] > The C11 memory model potentially adds overhead in only two cases: > > 1. When current code involves touching a field that wouldn't otherwise > be touched. There are odd cases in which this measurably slows down > code, but I think all agree that we need it. In addition to > bitfields, it can affect speculatively promoting a value to a register > in a loop, which at least older versions of gcc also do.
Just adding an -f option for this and/or activating it only for -O5 (or whatever the highest level is) and - in case that feature is activated - emit warnings if bitfields (and/or any other data types that might be affected)? Kind regards, Bernd -- Bernd Petrovitsch Email : be...@petrovitsch.priv.at LUGA : http://www.luga.at