https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111114
--- Comment #4 from Lehua Ding <lehua.ding at rivai dot ai> ---
(In reply to Andrew Pinski from comment #3)
> (In reply to Lehua Ding from comment #2)
> > (In reply to Andrew Pinski from comment #1)
> > > There is a match pattern which handles the case where the convert (cast)
> > > will fold both sides of the vec_cond now (since r14-3337-g70c50c87273d94).
> > >
> > > vect__5.14_56 = .MASK_LEN_LOAD (vectp_a.12_54, 8B, mask__24.11_52, _67,
> > > 0);
> > >
> > > Is there a way to simplify that with the convert?
> > >
> > > Or maybe we want to it if one or the other conversion simplifies ....
> > >
> > > Confirmed.
> >
> > Thanks for the comments. Can we relax this match by removing the modifier
> > "!"?
>
> I don't think so as we want to make sure we don't replace one operation
> happening with 2. The check really should be if one side will fold.
>
> We can special case VECTOR_CST here knowing that the convert will fold the
> CST always.
> So something like:
> ```
> (simplify
> (convert (vec_cond:s @0 @1 @2))
> (if (VECTOR_TYPE_P (type)
> && types_match (TREE_TYPE (@0), truth_type_for (type)))
> (if (TREE_CODE (@1) == VECTOR_CST || TREE_CODE (@2) == VECTOR_CST)
> (vec_cond @0 (convert @1) (convert @2)
> (vec_cond @0 (convert! @1) (convert! @2)))))
> ```
> We should do a similar trick to both the unary operator and view_convert too.
Just to double check, are you saying something like the bellow? But I don't
feel like the purpose is quite the same though. The match here was supposed to
remove the CONVERT operation. Whereas I was hoping to reverse the order in
order to combine them.
```
(simplify
(convert (vec_cond:s @0 @1 @2))
(if (VECTOR_TYPE_P (type)
&& types_match (TREE_TYPE (@0), truth_type_for (type))
&& (TREE_CODE (@1) == VECTOR_CST || TREE_CODE (@2) == VECTOR_CST))
(vec_cond @0 (convert @1) (convert @2))))
```
