[RFC] GCC port for ARM's Scalable Vector Extension

[Richard Sandiford]

Richard Sandiford <richard.sandiford@arm.com> writes:
> We have various other changes that aren't yet in the branch.  The two
> main ones are:
>
> (a) Support for gather loads and scatter stores.  This includes support
>     for using gathers and scatters for strided loads and stores, or for
>     grouped loads and stores whose group size is too large for a more
>     efficient approach.
>
> (b) Support for vectorising uncounted loops, i.e. those in which the number
>     of iterations isn't known before the loop starts.  This has two modes:
>
>      (i) Use alignment to avoid partial faults in speculative loads,
>          if alignment is reachable for all loads and if there are no other
>          statements with side effects.
>
>     (ii) Use the SVE first-faulting instruction for general speculative
>          loads.  This is the more general case and works regardless of
>          alignment.
>
> We hope to upload these changes to the branch soon.

FWIW, I've now uploaded those other changes to the branch.  The commit
messages use:

   [Branch only patch -- not intended for trunk in its current state]

to mark the patches that we know need tidying up a bit for trunk.
I didn't send them to gcc-patches@ because I thought they would be
noise.

The new patches span the range r243045:r243080 inclusive.

Thanks,
Richard