[Bug tree-optimization/33315] stores not commoned by sinking

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33315

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 48279
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48279&action=edit
patch

Patch forward ported to current trunk.