[all-commits] [llvm/llvm-project] 7a1e73: Recommit "[VPlan] Add recipe for first-order rec p...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 7a1e73f0b9fcfec0e90aff735f0ac4cfb6b9ec41
      https://github.com/llvm/llvm-project/commit/7a1e73f0b9fcfec0e90aff735f0ac4cfb6b9ec41
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2021-07-26 (Mon, 26 Jul 2021)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/lib/Transforms/Vectorize/VPlan.cpp
    M llvm/lib/Transforms/Vectorize/VPlan.h
    M llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
    M llvm/lib/Transforms/Vectorize/VPlanValue.h
    M llvm/test/Transforms/LoopVectorize/first-order-recurrence-complex.ll
    M llvm/test/Transforms/LoopVectorize/first-order-recurrence-sink-replicate-region.ll
    M llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll
    M llvm/test/Transforms/LoopVectorize/induction.ll
    M llvm/test/Transforms/LoopVectorize/interleaved-accesses.ll
    M llvm/test/Transforms/LoopVectorize/scalable-first-order-recurrence.ll
    M llvm/test/Transforms/LoopVectorize/vplan-sink-scalars-and-merge.ll

  Log Message:
  -----------
  Recommit "[VPlan] Add recipe for first-order rec phis, make splicing explicit."

This reverts the revert commit b1777b04dc4b1a9fee0e7effa7e177892ab32ef0.

The patch originally got reverted due to a crash:
https://bugs.chromium.org/p/chromium/issues/detail?id=1232798#c2

The underlying issue was that we were not using the stored values from
the modified memory recipes, but the out-of-date values directly from
the IR (accessed via the VPlan). This should be fixed in d995d6376. A
reduced version of the reproducer has been added in 93664503be6b.