[PATCH] D110613: [Taildup] Don't tail-duplicate loop header with multiple successors as its latches

Tue Sep 28 02:20:16 PDT 2021

junparser added a comment.

F19290850: huge-switch.ll <https://reviews.llvm.org/F19290850>

reduced bc file.

  $time llc-after --filetype=asm -O3   huge-switch.ll  -o huge-switch.s

  real    0m0.454s
  user    0m0.436s
  sys     0m0.012s

  time llc-before -O3 --filetype=asm  huge-switch.ll   -o huge-switch-1.s

  real    0m14.714s
  user    0m14.297s
  sys     0m0.134s

The backend spend lots of time to build cfg&loop chain. also it has worse code.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D110613/new/

https://reviews.llvm.org/D110613