[all-commits] [llvm/llvm-project] 40ec79: [RegAllocFast] Refactor dominates algorithm for la...

[HaohaiWen via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 40ec791b15b0110785a91b057e95535e8b0989b6
      https://github.com/llvm/llvm-project/commit/40ec791b15b0110785a91b057e95535e8b0989b6
  Author: HaohaiWen <haohai.wen at intel.com>
  Date:   2023-12-22 (Fri, 22 Dec 2023)

  Changed paths:
    M llvm/lib/CodeGen/RegAllocFast.cpp

  Log Message:
  -----------
  [RegAllocFast] Refactor dominates algorithm for large basic block (#72250)

The original brute force dominates algorithm is O(n) complexity so it is
very slow for very large machine basic block which is very common with
O0. This patch added InstrPosIndexes to assign index for each
instruction and use it to determine dominance. The complexity is now
O(1).