[all-commits] [llvm/llvm-project] 56bbf8: [BOLT] CDSplit main logic part 1/2 (#73895)

[ShatianWang via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 56bbf8135eb8b7d133d5d5fc7604d66f5011c57b
      https://github.com/llvm/llvm-project/commit/56bbf8135eb8b7d133d5d5fc7604d66f5011c57b
  Author: ShatianWang <38512325+ShatianWang at users.noreply.github.com>
  Date:   2023-11-30 (Thu, 30 Nov 2023)

  Changed paths:
    M bolt/lib/Core/FunctionLayout.cpp
    M bolt/lib/Passes/SplitFunctions.cpp

  Log Message:
  -----------
  [BOLT] CDSplit main logic part 1/2 (#73895)

This diff defines and initializes auxiliary variables used by CDSplit
and implements two important helper functions. The first helper function
approximates the block level size increase if a function is hot-warm
split at a given split index (X86 specific). The second helper function
finds all calls in the form of X->Y or Y->X for each BF given function
order [... X ... BF ... Y ...]. These calls are referred to as "cover
calls". Their distance will decrease if BF's hot fragment size is
further reduced by hot-warm splitting. NFC.