Bug 89754

Summary: Vectorizer cost model check should look at evolution of niter in outer loop(s)
Product: gcc Reporter: Richard Biener <rguenth>
Component: tree-optimizationAssignee: Not yet assigned to anyone <unassigned>
Status: NEW ---    
Severity: enhancement CC: rsandifo
Priority: P3    
Version: 9.0   
Target Milestone: ---   
Host: Target:
Build: Known to work:
Known to fail: Last reconfirmed: 2019-03-18 00:00:00
Bug Depends on:    
Bug Blocks: 53947, 87561    

Description Richard Biener 2019-03-18 10:01:47 UTC
For the testcase in PR87561 which has a loop nest iterating over a triangle
the vectorizer should take the evolution of the inner loop niter in the outer
loop into account for cost modeling and compute a cost model check for the
outer loop also applying cost model versioning to the outer loop instead of
the inner loop.
Comment 1 Richard Biener 2019-03-18 10:02:23 UTC
If implemented the awkward x86 cost model adjustments might not be neccessary.