[Bug tree-optimization/100794] suboptimal code due to missing pre2 when vectorization fails

[linkw at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100794

--- Comment #6 from Kewen Lin <linkw at gcc dot gnu.org> ---
Created attachment 50894
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50894&action=edit
Method 1, implicitly enable pcom without unrolling once loop vectorization is
enabled but pcom isn't set explicitly.