[llvm] [CodeGen] Port selection dag isel to new pass manager (PR #83567)

[Matt Arsenault via llvm-commits]

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@@ -341,9 +341,34 @@ void TargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
 // SelectionDAGISel code
 //===----------------------------------------------------------------------===//
 
-SelectionDAGISel::SelectionDAGISel(char &ID, TargetMachine &tm,
-                                   CodeGenOptLevel OL)
-    : MachineFunctionPass(ID), TM(tm), FuncInfo(new FunctionLoweringInfo()),
+SelectionDAGISelLegacy::SelectionDAGISelLegacy(
+    char &ID, std::unique_ptr<SelectionDAGISel> S)
+    : MachineFunctionPass(ID), Selector(std::move(S)) {
+  initializeGCModuleInfoPass(*PassRegistry::getPassRegistry());
+  initializeBranchProbabilityInfoWrapperPassPass(
+      *PassRegistry::getPassRegistry());
+  initializeAAResultsWrapperPassPass(*PassRegistry::getPassRegistry());
+  initializeTargetLibraryInfoWrapperPassPass(*PassRegistry::getPassRegistry());
+}
+
+bool SelectionDAGISelLegacy::runOnMachineFunction(MachineFunction &MF) {
+  // If we already selected that function, we do not need to run SDISel.
+  if (MF.getProperties().hasProperty(
+          MachineFunctionProperties::Property::Selected))
+    return false;
+
+  // Do some sanity-checking on the command-line options.
+  assert((!EnableFastISelAbort || Selector->TM.Options.EnableFastISel) &&
+         "-fast-isel-abort > 0 requires -fast-isel");
+
+  Selector->MF = &MF;
+  Selector->prepare(MF);
+  Selector->initialize(*this);
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arsenm wrote:

Having both "prepare" and "initialize" feels redundant 

https://github.com/llvm/llvm-project/pull/83567