On Tue, Jul 30, 2024 at 03:00:49PM +0200, Richard Biener wrote: > As Jakub said the padding is already dealt with in the caller > though I only added that there for convenience since padding is > problematic in general. > > If you think XFmode is safe to transfer 10 bytes we could enable it, > I guess I'll amend the docs to be clear: > > "Define this to return false if the mode @var{mode} cannot be used > for memory copying. The default is to assume modes with the same > precision as size are fine to be used." > > this might suggest transfering GET_MODE_PRECISION bits is intended > but it might want to say GET_MODE_SIZE units explicitly so the > default makes sense.
You could just gcc_unreachable (); for XFmode in the link with a short comment that the mode has padding. Jakub