[llvm-branch-commits] [llvm] [CodeGen][NewPM] Port MachineCSE pass to new pass manager. (PR #106605)

[Christudasan Devadasan via llvm-branch-commits]

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@@ -932,18 +935,55 @@ bool MachineCSE::isProfitableToHoistInto(MachineBasicBlock *CandidateBB,
          MBFI->getBlockFreq(MBB) + MBFI->getBlockFreq(MBB1);
 }
 
-bool MachineCSE::runOnMachineFunction(MachineFunction &MF) {
-  if (skipFunction(MF.getFunction()))
-    return false;
+void MachineCSEImpl::releaseMemory() {
+  ScopeMap.clear();
+  PREMap.clear();
+  Exps.clear();
+}
 
+bool MachineCSEImpl::run(MachineFunction &MF) {
   TII = MF.getSubtarget().getInstrInfo();
   TRI = MF.getSubtarget().getRegisterInfo();
   MRI = &MF.getRegInfo();
-  DT = &getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree();
-  MBFI = &getAnalysis<MachineBlockFrequencyInfoWrapperPass>().getMBFI();
   LookAheadLimit = TII->getMachineCSELookAheadLimit();
   bool ChangedPRE, ChangedCSE;
   ChangedPRE = PerformSimplePRE(DT);
   ChangedCSE = PerformCSE(DT->getRootNode());
+  releaseMemory();
   return ChangedPRE || ChangedCSE;
 }
+
+PreservedAnalyses MachineCSEPass::run(MachineFunction &MF,
+                                      MachineFunctionAnalysisManager &MFAM) {
+  MFPropsModifier _(*this, MF);
+
+  if (MF.getFunction().hasOptNone())
+    return PreservedAnalyses::all();
+
+  MachineDominatorTree &MDT = MFAM.getResult<MachineDominatorTreeAnalysis>(MF);
+  MachineBlockFrequencyInfo &MBFI =
+      MFAM.getResult<MachineBlockFrequencyAnalysis>(MF);
+  MachineCSEImpl Impl(&MDT, &MBFI);
+  bool Changed = Impl.run(MF);
+  if (!Changed)
+    return PreservedAnalyses::all();
+
+  auto PA = getMachineFunctionPassPreservedAnalyses();
+  PA.preserve<MachineLoopAnalysis>();
+  PA.preserve<MachineDominatorTreeAnalysis>();
----------------
cdevadas wrote:

Not sure about that. I have seen similar instances (DT being preserved along with the preserveSet) in other backend passes ported to NPM.

https://github.com/llvm/llvm-project/pull/106605