[PATCH] Fix PR19657 : SLP vectorization doesn't combine scalar load to vector loads

[Karthik Bhat]

Hi Nadav,
Please find the performance result with and without patch. I dont see large regression in compilation time though execution time of one test case improved greatly. The baseline is without patch and current is with patch.

{F60858}

Hi Raul,Arnold
I agree that the current patch will not handle the case mentioned. I was thinking of handling unschedulable loads again after buildTree_rec was completed but as arnold mentioned i'm not sure if this would be worth the ovehead.

For now do you think we can move ahead with this approach as we are able to vectorize loads similar to one's mentioned in the PR without much overhead?

Thanks  for all the comments and review.

Regards
Karthik Bhat

http://reviews.llvm.org/D3800