[Bug target/81504] [7/8 Regression] gcc-7 regression: vec_st in loop misoptimized

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81504

--- Comment #4 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
I don't think this has anything to do with the swaps pass.  I see the same
wrong code generation with -mno-optimize-swaps.  I'll continue to investigate.