[all-commits] [llvm/llvm-project] ee8726: [VPlan] Expand VPExpandSCEVRecipes to VPInstructio...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ee872666e2881119b66b137c590a59eeace22996
      https://github.com/llvm/llvm-project/commit/ee872666e2881119b66b137c590a59eeace22996
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2026-05-29 (Fri, 29 May 2026)

  Changed paths:
    M llvm/include/llvm/Analysis/ScalarEvolution.h
    M llvm/include/llvm/Transforms/Utils/ScalarEvolutionExpander.h
    M llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
    M llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/lib/Transforms/Vectorize/VPlanConstruction.cpp
    M llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
    M llvm/lib/Transforms/Vectorize/VPlanTransforms.h
    M llvm/lib/Transforms/Vectorize/VPlanUtils.cpp
    M llvm/lib/Transforms/Vectorize/VPlanUtils.h
    M llvm/test/Transforms/LoopVectorize/AArch64/sve-vscale-based-trip-counts.ll
    M llvm/test/Transforms/LoopVectorize/AArch64/vector-loop-backedge-elimination-epilogue.ll
    M llvm/test/Transforms/LoopVectorize/VPlan/vplan-printing.ll
    M llvm/test/Transforms/LoopVectorize/float-induction.ll
    M llvm/test/Transforms/LoopVectorize/if-reduction.ll
    M llvm/test/Transforms/LoopVectorize/induction-step.ll
    M llvm/test/Transforms/LoopVectorize/pointer-induction.ll
    M llvm/test/Transforms/LoopVectorize/pr31190.ll

  Log Message:
  -----------
  [VPlan] Expand VPExpandSCEVRecipes to VPInstructions before CSE. (#197643)

Add expandSCEVExpressions transform that converts VPExpandSCEVRecipes
to VPInstructions where possible, running before CSE so duplicates with
other SCEV expansions (e.g., from addMinimumIterationCheck) are
eliminated. This also reuses existing loop-invariant IR values via
ScalarEvolution::getSCEVValues to avoid redundant computation.

Currently limited to SCEVMulExpr (along with constants, unknowns, and
vscale). Support for SCEVAddExpr and SCEVUDivExpr will follow in
subsequent patches.

Depends on https://github.com/llvm/llvm-project/pull/189455

PR: https://github.com/llvm/llvm-project/pull/197643



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications