https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99195
--- Comment #1 from ktkachov at gcc dot gnu.org ---
Using a define_subst like:
(define_subst "add_vec_concat_subst"
[(set (match_operand:VDMOV 0 "" "")
(match_operand:VDMOV 1 "" ""))]
"!BYTES_BIG_ENDIAN"
[(set (match_operand:<VDBL> 0 "register_operand" "=w")
(vec_concat:<VDBL>
(match_dup 1)
(match_operand:VDMOV 2 "aarch64_simd_or_scalar_imm_zero")))]
)
(define_subst_attr "add_vec_concat" "add_vec_concat_subst" "" "_vec_concat")
and adding it to patterns in aarch64-simd.md through <add_vec_concat> seems to
work. It doesn't handle the big-endian case, but maybe we can handle that
separately (or with a second define_subst?)
Does this approach make sense?
