[PATCH] D130994: [DAGCombiner] Hoist funnel shifts from logic operation.

[Filipp Zhinkin via Phabricator via llvm-commits]

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Hoist funnel shift from logic op:
logic_op (FSH x0, x1, s), (FSH y0, y1, s)

  --> FSH (logic_op x0, y0), (logic_opt x1, y1), s

The transformation improves code generated for some cases related to
issue https://github.com/llvm/llvm-project/issues/49541.

Reduced amount of funnel shifts can also improve throughput on x86 CPUs
by utilizing more available ports:
https://quick-bench.com/q/gC7AKkJJsDZzRrs_JWDzm9t_iDM


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D130994

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/X86/funnel-shift-logic-fold.ll
  llvm/test/CodeGen/X86/icmp-shift-opt.ll

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