https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117173
--- Comment #2 from Robin Dapp ---
In x264, before the optimization we have:
_42 = VEC_PERM_EXPR ;
...
_44 = VEC_PERM_EXPR ;
_45 = VEC_PERM_EXPR ;
The first one (_42) is "monotonic" and can be implemented by a vmerge. This
implies a load and
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117173
--- Comment #1 from Richard Biener ---
So on the GIMPLE side this is mostly canonicalization - the "theory" is that
the backend should be able to implement VEC_PERM_EXPR
using the same two cheap permutes facing this premute request.
I don't se
