[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 #14 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #13)
> (In reply to Richard Biener from comment #12)
> > Created attachment 48279 [details]
> > patch
> > 
> > Patch forward ported to current trunk.
> 
> Surprisingly small fallout:
> 
> FAIL: gcc.dg/tree-ssa/split-path-7.c scan-tree-dump-times split-paths
> "Duplicating join block" 0
> 
> I've thought the approach is too simplistic but I'll do some statistics
> over bootstrap in stage1 and push it if it looks useful - we certainly
> have more "hackish" optimization pieces.

stage3 gcc/ files show (first column is the number of edges we sink from,
second column the number of stores we sink):

2: 3195
3: 193
4: 130
5: 55
6: 28
7: 4
8: 9
9: 3
10: 3
12: 1
13: 6
16: 2
18: 1
22: 2

so it seems worth it.