[PATCH] D78298: [LV] Invalidate cost model decisions along with interleave groups.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: gilr, rengolin, Ayal, hsaito.
Herald added subscribers: rogfer01, rkruppe, bollu, hiraditya.
Herald added a project: LLVM.

Cost-modeling decisions are tied to the compute interleave groups
(widening decisions, scalar and uniform values). We invalidating the
interleave groups, those decisions also need to be invalidated.

Otherwise there is a mis-match during VPlan construction where no
VPInterleave recipes are created and VPWidenMemoryRecipes are left
around for instructions marked as interleaved. This happens if
a vectorization factor is chosen for which computeMaxVF already computed
the CM decisions.

Alternatively to forcing a complete recompute later on, we could try
to selectively invalidate the decisions connected to the interleave
groups. But we would likely need to run the uniform/scalar value
detection parts again anyways and the extra complexity is probably not
worth it.

Fixes PR45572.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D78298

Files:
  llvm/include/llvm/Analysis/VectorUtils.h
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/test/Transforms/LoopVectorize/Hexagon/invalidate-cm-after-invalidating-interleavegroups.ll

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