[Bug tree-optimization/63185] Improve DSE with branches

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63185

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Btw, what was the original testcase?

It's all a little bit complicated and not really fit for the current simple
handling of PHIs.  Because with a conditional store we have to continue
looking for uses on the other path (for regular stores we'd have expected
code sinking to sink the store).

That is, without making the walk very much more expensive there isn't anything
we can do about this.