[all-commits] [llvm/llvm-project] ede6d6: [VectorCombine] switch on opcode to compile faster

[Sanjay Patel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ede6d608f4a92ef508b91f0a37f5b9dc1de45f47
      https://github.com/llvm/llvm-project/commit/ede6d608f4a92ef508b91f0a37f5b9dc1de45f47
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-11-22 (Tue, 22 Nov 2022)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/VectorCombine.cpp

  Log Message:
  -----------
  [VectorCombine] switch on opcode to compile faster

This follows 87debdadaf18 to further eliminate wasting time
calling helper functions only to early return to the main
run loop.

Once again, this results in significant savings based on
experimental data:
https://llvm-compile-time-tracker.com/compare.php?from=01023bfcd33f922ed8c934ce563e54abe8bfe246&to=3dce4f70b73e48ccb045decb634c185e6b4c67d5&stat=instructions:u

This is NFCI other than making the pass faster. The total
cost of VectorCombine runs in an -O3 build appears to be
well under 0.1% of compile-time now, so there's not much
left to do AFAICT.

There's a TODO about making the code cleaner, but it
probably doesn't change timing much. I didn't include those
changes here because it requires updating much more code.