[all-commits] [llvm/llvm-project] 8f781b: Revert "[VPlan] Mark recurrence recipes as not hav...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8f781b96e201408d1fb7b49367876a54682594ed
      https://github.com/llvm/llvm-project/commit/8f781b96e201408d1fb7b49367876a54682594ed
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2023-06-06 (Tue, 06 Jun 2023)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
    M llvm/test/Transforms/LoopVectorize/X86/fixed-order-recurrence.ll
    M llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll

  Log Message:
  -----------
  Revert "[VPlan] Mark recurrence recipes as not having side-effects."

This reverts commit 02369b75fdd7b5fc5d9b47f1b60587c225918511.

At the moment, live-outs used *only* for the resume values in the scalar
loop are not modeled in VPlan yet. This means first-order recurrence
recipes could be removed, when a scalar epilogue is required and the
only use of a FOR is outside the loop.

Keep treating recurrence recipes as having side-effects for now, to
avoid them being removed.

Fixes #62954.