On Mon, Sep 18, 2023 at 01:26:54PM +0200, Martin Uecker wrote: > > I think that changing the default to =standard without -ffast-math is > > reasonable. > > IIRC the standard allows such default if it's indicated, so it doesn't > > require > > =off anywhere. > > The C standard requires a pragma to turn control it on and off, > which GCC does not support. The default is then implementation > defined.
Perhaps we should add some initial hammer approach for the pragma, like if you ever use the pragma to turn it somewhere off, it is turned off globally, or ditto per function. Might be far easier than trying to make it precise that contraction is allowed in this expression and not in this subexpression of that etc. Of course, making it precise is the ultimate goal. Jakub