[Bug tree-optimization/85999] New: 416.gamess slowed down by BB vectorization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85999

            Bug ID: 85999
           Summary: 416.gamess slowed down by BB vectorization
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

Adding -ftree-slp-vectorize to -O2 -march=haswell [-mprefer-avx128] on
416.gamess
slows down the benchmark significantly.  Adding -fno-tree-slp-vectorize to
-Ofast -march=haswell speeds it up.

Thus somehow BB vectorization slows down 416.gamess.