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[Dominators][CodeGen] Clean up MachineDominators
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Authored by kuhar on Sep 24 2019, 12:00 PM.

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Summary

This is a cleanup patch for MachineDominatorTree. It would be an NFC, except for replacing custom DomTree verification with the generic one.

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Repository
rL LLVM

Event Timeline

kuhar created this revision.Sep 24 2019, 12:00 PM
Herald added a project: Restricted Project. · View Herald Transcript
kuhar added a reviewer: hliao.Sep 27 2019, 9:04 AM
arsenm accepted this revision.Sep 27 2019, 9:40 AM

LGTM

This revision is now accepted and ready to land.Sep 27 2019, 9:40 AM
This revision was automatically updated to reflect the committed changes.

The changes to verifier caught a MDT bug on AArch64:

test/CodeGen/AArch64/tailmerging_in_mbp.ll -mtriple=aarch64-eabi -verify-machine-dom-info 
DominatorTree is different than a freshly computed one!
	Current:
=============================--------------------------------
Inorder Dominator Tree: DFSNumbers invalid: 25 slow queries.
  [1] %bb.0 {4294967295,4294967295} [0]
    [2] %bb.1 {4294967295,4294967295} [1]
      [3] %bb.2 {4294967295,4294967295} [2]
        [4] %bb.3 {4294967295,4294967295} [3]
          [5] %bb.7 {4294967295,4294967295} [4]
          [5] %bb.4 {4294967295,4294967295} [4]
            [6] %bb.5 {4294967295,4294967295} [5]
              [7] %bb.6 {4294967295,4294967295} [6]
    [2] %bb.8 {4294967295,4294967295} [1]
Roots: %bb.0 

	Freshly computed tree:
=============================--------------------------------
Inorder Dominator Tree: DFSNumbers invalid: 0 slow queries.
  [1] %bb.0 {4294967295,4294967295} [0]
    [2] %bb.1 {4294967295,4294967295} [1]
      [3] %bb.2 {4294967295,4294967295} [2]
        [4] %bb.9 {4294967295,4294967295} [3]
        [4] %bb.3 {4294967295,4294967295} [3]
          [5] %bb.7 {4294967295,4294967295} [4]
          [5] %bb.4 {4294967295,4294967295} [4]
            [6] %bb.10 {4294967295,4294967295} [5]
            [6] %bb.5 {4294967295,4294967295} [5]
              [7] %bb.6 {4294967295,4294967295} [6]
                [8] %bb.11 {4294967295,4294967295} [7]
    [2] %bb.8 {4294967295,4294967295} [1]
Roots: %bb.0 
MachineDominatorTree verification failed

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