[all-commits] [llvm/llvm-project] a65f27: [VPlan] Expand induction step in VPlan pre-header.

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a65f2730d291e83f4fa39d3cb104b36c86f36e73
      https://github.com/llvm/llvm-project/commit/a65f2730d291e83f4fa39d3cb104b36c86f36e73
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2022-04-19 (Tue, 19 Apr 2022)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
    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/VPlanTransforms.h
    M llvm/test/Transforms/LoopVectorize/first-order-recurrence-sink-replicate-region.ll
    M llvm/test/Transforms/LoopVectorize/icmp-uniforms.ll
    M llvm/test/Transforms/LoopVectorize/vplan-printing.ll
    M llvm/test/Transforms/LoopVectorize/vplan-sink-scalars-and-merge.ll

  Log Message:
  -----------
  [VPlan] Expand induction step in VPlan pre-header.

This patch moves SCEV expansion of steps used by
VPWidenIntOrFpInductionRecipes to the pre-header using
VPExpandSCEVRecipe. This ensures that those steps are expanded while the
CFG is in a valid state. Previously, SCEV expansion may happen during
vector body code-generation, during which the CFG may be invalid,
causing issues with SCEV expansion.

Depends on D122095.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D122096