[all-commits] [llvm/llvm-project] 8b7c3d: [LV] Set SCEVCheckCond to nullptr whenever it was ...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8b7c3d2179b3c0dadb957ff255d7bdf3283474a8
      https://github.com/llvm/llvm-project/commit/8b7c3d2179b3c0dadb957ff255d7bdf3283474a8
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2022-05-15 (Sun, 15 May 2022)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    A llvm/test/Transforms/LoopVectorize/pr55100-expand-scev-predicate-used.ll

  Log Message:
  -----------
  [LV] Set SCEVCheckCond to nullptr whenever it was used.

Under some circumstances, SCEVExpander will insert new instructions when
expanding a predicate, but the final result of the expansion can be a
false constant.

In those cases, the expanded instructions may later be used by other
expansions, e.g. the trip count. This may trigger an assertion during
SCEVExpander cleanup. To avoid this, always mark the result as used.

Fixes #55100.