[all-commits] [llvm/llvm-project] a59f99: [SLP] Recompute copyable operand deps for duplicat...

[Alexey Bataev via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a59f9951f3e197127fb13d729ad4c52168f29432
      https://github.com/llvm/llvm-project/commit/a59f9951f3e197127fb13d729ad4c52168f29432
  Author: Alexey Bataev <a.bataev at outlook.com>
  Date:   2026-05-30 (Sat, 30 May 2026)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
    A llvm/test/Transforms/SLPVectorizer/AArch64/recalc-copyable-node.ll

  Log Message:
  -----------
  [SLP] Recompute copyable operand deps for duplicate copyable nodes

A bundle may duplicate a previously built node that has copyable elements
(same schedulable instructions, different copyable lane) while the parent
node also has copyable elements. An operand modeled as a copyable element
in the previous node is then used directly by the new node, which is not
registered in the tree yet. Recomputing that operand's direct
dependencies at this point misses the direct use, so the scheduler
decrements the operand more times than its dependency count and trips the
unscheduled-deps assertion.
Defer recomputation of such operand dependencies via
RecalcCopyableOperandDeps and redo it at the next bundle scheduling, when
the duplicate node is part of the tree. Also clear and recompute the
direct dependencies of bundles whose user is a gather node referenced
through EdgeIdx == UINT_MAX in scheduleBlock, so combined gather
sub-entries get correct dependencies against the full tree.

Reviewers: 

Pull Request: https://github.com/llvm/llvm-project/pull/200564



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