[all-commits] [llvm/llvm-project] b5db65: Reland [GlobalOpt] Preserve CFG analyses

[aeubanks via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b5db65e0da1748d58b0657b4ffb3a41d7fd58449
      https://github.com/llvm/llvm-project/commit/b5db65e0da1748d58b0657b4ffb3a41d7fd58449
  Author: Arthur Eubanks <aeubanks at google.com>
  Date:   2022-06-21 (Tue, 21 Jun 2022)

  Changed paths:
    M llvm/lib/Transforms/IPO/GlobalOpt.cpp
    A llvm/test/Transforms/GlobalOpt/analysis-invalidation.ll

  Log Message:
  -----------
  Reland [GlobalOpt] Preserve CFG analyses

The only place we modify the CFG is when calling
removeUnreachableBlocks(), so insert a callback there which invalidates
analyses for that function (or recomputes DT in the legacy PM).

We may delete functions, make sure to clear analyses for those
functions. (this was missed in the original revision)

Small compile time wins across the board:
https://llvm-compile-time-tracker.com/compare.php?from=f444ea8ce0aaaa5ec1a4129809389da15cc41396&to=698f41f4fc26cbf1006ed5d88e9d658edfc5b749&stat=instructions

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D128145