Hi, On Fri, 16 Nov 2018, Segher Boessenkool wrote:
> > I.e. like volatile they can arbitrarily change their value. I don't > > know if other peoples mind model is similar, but it certainly is the > > model that is implemented in the GIMPLE pipeline (and if memory serves > > well of the RTL pipeline as well). > > > > Copying outof/into pseudos around asms serves no purpose with that > > model, it rather makes regvars somewhat "safer" to use, without > > actually making them safer (there _is_ nothing safe about them). > > The only supported case is for inputs and outputs to extended asm. > Maybe we should just come up with a syntax so you can specify hard regs > for that directly (without needing a separate regclass for every reg). I would like that, yes. (Of course backward compat would have us support the historic usage for some time, but still ...) Ciao, Michael.
