[all-commits] [llvm/llvm-project] 0d0190: [TailDup] Allow large number of predecessors/succe...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0d0190815d8f273e9d87c29b4779b81412b31e91
      https://github.com/llvm/llvm-project/commit/0d0190815d8f273e9d87c29b4779b81412b31e91
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2025-01-23 (Thu, 23 Jan 2025)

  Changed paths:
    M llvm/lib/CodeGen/TailDuplicator.cpp
    M llvm/test/CodeGen/X86/tail-dup-pred-succ-size.mir

  Log Message:
  -----------
  [TailDup] Allow large number of predecessors/successors without phis. (#116072)

This adjusts the threshold logic added in #78582 to only trigger for
cases where there are actually phis to duplicate in either TailBB or in
one of the successors.

In cases there are no phis, we only have to pay the cost of extra edges,
but have no explosion in PHI related instructions.

This improves performance of Python on some inputs by 2-3% on Apple
Silicon CPUs.

PR: https://github.com/llvm/llvm-project/pull/116072



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