[all-commits] [llvm/llvm-project] 0130d0: [SCEV] Compute symbolic exit count for 'and' condi...

[Max Kazantsev via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0130d0ed35e8788be502f14cdb8b5569a6db527a
      https://github.com/llvm/llvm-project/commit/0130d0ed35e8788be502f14cdb8b5569a6db527a
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2022-12-08 (Thu, 08 Dec 2022)

  Changed paths:
    M llvm/lib/Analysis/ScalarEvolution.cpp
    M llvm/test/Analysis/ScalarEvolution/symbolic_max_exit_count.ll

  Log Message:
  -----------
  [SCEV] Compute symbolic exit count for 'and' conditions

If loop exits by condition like `A < B && X < Y`, and at least one of symbolic max
exit counts for these conditions is known, it can be used as estimate of symbolic
max exit count for whole branch. If both are known, then we can use their umin
as the estimate.

Differential Revision: https://reviews.llvm.org/D139403
Reviewed By: nikic