On Mon, 30 Nov 2015, Jakub Jelinek wrote: > On Mon, Nov 30, 2015 at 02:30:04PM +0000, Richard Sandiford wrote: > > > keep the builtin_reciprocal hook (perhaps renamed to builtin_rsqrt) > > > for the purpose of this condition and nothing else (i.e. return a > > > boolean) and let the rest be determined from the optab, just commit > > > the already posted patch, something else? > > > > ...I suppose the problem with adding extra conditions to the expander > > is that it would break cases where the expander is used for target > > built-ins too. > > > > Maybe optabs shouldn't be used for built-ins if the usage conditions > > aren't the same. But if that's fighting too much against existing usage, > > the hook "hack" could check these conditions too. > > Yeah, I'm aware that the target builtins use those expanders with the > current conditions and so would need to be renamed to something different > if we take the approach of adding the conditions to all rsqrt* expanders. > > So, maybe it is best if I just apply my original patch right away so that > the bug is fixed and we can continue discussions on how we want to handle > it.
Yes, I've seen the IFN idea as a followup improvement and go with your original patch for now. Richard.
