[PATCH] D63972: [CodeGen] Do the Simple Early Return in block-placement pass to optimize the blocks

[Zhang Kang via Phabricator via llvm-commits]

ZhangKang added a comment.

In D63972#1612791 <https://reviews.llvm.org/D63972#1612791>, @efriedma wrote:

> Can you remove the dead `MachineDominatorTree *MDT;` declaration?
>
> > the function MachineBlockPlacement::runOnMachineFunction will do some clean work and will never use the MachinePostDominatorTree info, and this pass don't preserve the MachinePostDominatorTree
>
> Please add this explanation as an explicit comment in the code.


This pass don't definite and use the `MachineDominatorTree`, it only defines and uses the  `MachinePostDominatorTree`. I will add the comment about the change of `MachinePostDominatorTree`.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D63972/new/

https://reviews.llvm.org/D63972