[llvm] [NewPM] Adds a port for AArch64PostCoalescerPass (PR #189520)

[Aiden Grossman via llvm-commits]

================
@@ -100,6 +65,58 @@ bool AArch64PostCoalescer::runOnMachineFunction(MachineFunction &MF) {
   return Changed;
 }
 
+struct AArch64PostCoalescerLegacy : public MachineFunctionPass {
+  static char ID;
+
+  AArch64PostCoalescerLegacy() : MachineFunctionPass(ID) {}
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+  StringRef getPassName() const override {
+    return "AArch64 Post Coalescer pass";
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesCFG();
+    AU.addRequired<LiveIntervalsWrapperPass>();
+    AU.addPreserved<LiveIntervalsWrapperPass>();
+    AU.addPreserved<SlotIndexesWrapperPass>();
+    MachineFunctionPass::getAnalysisUsage(AU);
+  }
+};
+
+char AArch64PostCoalescerLegacy::ID = 0;
+
+} // end anonymous namespace
+
+INITIALIZE_PASS_BEGIN(AArch64PostCoalescerLegacy, "aarch64-post-coalescer",
+                      "AArch64 Post Coalescer Pass", false, false)
+INITIALIZE_PASS_DEPENDENCY(LiveIntervalsWrapperPass)
+INITIALIZE_PASS_END(AArch64PostCoalescerLegacy, "aarch64-post-coalescer",
+                    "AArch64 Post Coalescer Pass", false, false)
+
+bool AArch64PostCoalescerLegacy::runOnMachineFunction(MachineFunction &MF) {
+  if (skipFunction(MF.getFunction()))
+    return false;
+
+  auto &LIS = getAnalysis<LiveIntervalsWrapperPass>().getLIS();
+  return runAArch64PostCoalescer(MF, LIS);
+}
+
+PreservedAnalyses
+AArch64PostCoalescerPass::run(MachineFunction &MF,
+                              MachineFunctionAnalysisManager &MFAM) {
+  auto &LIS = MFAM.getResult<LiveIntervalsAnalysis>(MF);
+  const bool Changed = runAArch64PostCoalescer(MF, LIS);
+  if (!Changed)
+    return PreservedAnalyses::all();
+  PreservedAnalyses PA = getMachineFunctionPassPreservedAnalyses();
+  PA.preserveSet<CFGAnalyses>();
+  PA.preserve<LiveIntervalsAnalysis>();
+  PA.preserve<SlotIndexesAnalysis>();
----------------
boomanaiden154 wrote:

We should probably add a TODO here that eventually `SlotIndexes` should only invalidate itself if `LiveIntervals` is invalidated.

https://github.com/llvm/llvm-project/pull/189520