[llvm] [CodeGen] Use optimized domtree for MachineFunction (PR #102107)

[Alexis Engelke via llvm-commits]

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@@ -364,13 +364,18 @@ bool MIRProfileLoaderPass::runOnMachineFunction(MachineFunction &MF) {
   LLVM_DEBUG(dbgs() << "MIRProfileLoader pass working on Func: "
                     << MF.getFunction().getName() << "\n");
   MBFI = &getAnalysis<MachineBlockFrequencyInfoWrapperPass>().getMBFI();
+  auto *MDT = &getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree();
+  auto *MPDT =
+      &getAnalysis<MachinePostDominatorTreeWrapperPass>().getPostDomTree();
+
+  MF.RenumberBlocks();
+  MDT->updateBlockNumbers();
+  MPDT->updateBlockNumbers();
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aengelke wrote:

I considered, but wanted to avoid the dependency of MachineFunction -> DomTree. Given that we would default-initialize these parameters to null, I also don't think that it makes mistakes less likely. Use of outdated numbers is guarded by an assertion.

https://github.com/llvm/llvm-project/pull/102107