[Bug target/55295] [SH] Add support for fipr instruction

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55295

--- Comment #11 from Oleg Endo <olegendo at gcc dot gnu.org> ---
A note on the side...
As mentioned above, fipr can also be used to do a 3D dot product.  However,
GCC's vector extensions do not allow specifying vectors of length 3.  To
support that I guess the easiest way is to do it with a bunch of combine
patterns which canonicalize/split into the vector version.  Last time I've
tried, register allocation was pretty bad for that as mentioned in comment #10.
 Probably it will require some specific pre-allocation before RA.