[Bug target/104912] [12 Regression] 416.gamess regression after r12-7612-g69619acd8d9b58

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104912

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #2)
> PR87561 has a testcase and for it we pessimized strided loads & stores "a
> bit more" in r9-6581-g7d7d1ce83889ee and r9-6580-g0538ed1d3602ec

We're entering this CTOR cost pessimization with a cost of 4 now (down from 8),
aka one sse_op, and multiply that by 3.  I think it would be better to add
TYPE_VECTOR_SUBPARTS times ->lea cost, though that would not help here
obviously.

This cost pessimization is a (bad) workaround for the inability to handle
PR89754 and PR89755

Since we halved the CTOR cost we'd now need to apply that factor of two
ontop of the pessimization for strided loads/stores to recover.  Since
we only halved the CTOR case but not vec_to_scalar we get away with
just doing that for load_vec_info_type.