Bug 89754 - Vectorizer cost model check should look at evolution of niter in outer loop(s)
Summary: Vectorizer cost model check should look at evolution of niter in outer loop(s)
Status: NEW
Alias: None
Product: gcc
Classification: Unclassified
Component: tree-optimization (show other bugs)
Version: 9.0
: P3 enhancement
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks: vectorizer 87561
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Reported: 2019-03-18 10:01 UTC by Richard Biener
Modified: 2019-03-18 13:34 UTC (History)
1 user (show)

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Last reconfirmed: 2019-03-18 00:00:00

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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.