[all-commits] [llvm/llvm-project] 59365f: [MachineCSE] Add a threshold to avoid spending too...

[pzhengqc via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 59365f33e27b24b6ecc971c53889c8ac3b34b15d
      https://github.com/llvm/llvm-project/commit/59365f33e27b24b6ecc971c53889c8ac3b34b15d
  Author: Pengxuan Zheng <pzheng at quicinc.com>
  Date:   2022-09-16 (Fri, 16 Sep 2022)

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

  Log Message:
  -----------
  [MachineCSE] Add a threshold to avoid spending too much time in isProfitableToCSE

Currently, it can become extremely costly to compute MayIncreasePressure if the
size of CSUses turns out to be very large. In that case, it's no longer cost
effective to keep computing MayIncreasePressure. Therefore, to limit the amount
of time spent in isProfitableToCSE, we simply conservatively assume
MayIncreasePressure if the size of CSUses is too large. This can reduce overall
compile time by 30% for some benchmarks.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D134003