[llvm] [AMDGPU][NPM] Port SIModeRegister to NPM (PR #129014)

[Matt Arsenault via llvm-commits]

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@@ -422,7 +428,20 @@ void SIModeRegister::processBlockPhase3(MachineBasicBlock &MBB,
   }
 }
 
-bool SIModeRegister::runOnMachineFunction(MachineFunction &MF) {
+bool SIModeRegisterLegacy::runOnMachineFunction(MachineFunction &MF) {
+  return SIModeRegister().run(MF);
+}
+
+PreservedAnalyses SIModeRegisterPass::run(MachineFunction &MF,
+                                          MachineFunctionAnalysisManager &AM) {
+  if (SIModeRegister().run(MF))
+    return PreservedAnalyses::none();
+  auto PA = getMachineFunctionPassPreservedAnalyses();
+  PA.preserveSet<CFGAnalyses>();
+  return PA;
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arsenm wrote:

Should preserve all if it did nothing. Even if it did something, it probably preserves everything (at least CFG)

https://github.com/llvm/llvm-project/pull/129014