[llvm-branch-commits] [llvm] [CodeGen][NewPM] Port RegAllocPriorityAdvisor analysis to NPM (PR #118462)

[Matt Arsenault via llvm-branch-commits]

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@@ -68,20 +70,72 @@ class DummyPriorityAdvisor : public RegAllocPriorityAdvisor {
   unsigned getPriority(const LiveInterval &LI) const override;
 };
 
-class RegAllocPriorityAdvisorAnalysis : public ImmutablePass {
+/// Common provider for getting the priority advisor and logging rewards.
+/// Legacy analysis forwards all calls to this provider.
+/// New analysis serves the provider as the analysis result.
+/// Expensive setup is done in the constructor, so that the advisor can be
+/// created quickly for every machine function.
+/// TODO: Remove once legacy PM support is dropped.
+class RegAllocPriorityAdvisorProvider {
 public:
   enum class AdvisorMode : int { Default, Release, Development, Dummy };
 
-  RegAllocPriorityAdvisorAnalysis(AdvisorMode Mode)
-      : ImmutablePass(ID), Mode(Mode){};
+  RegAllocPriorityAdvisorProvider(AdvisorMode Mode) : Mode(Mode) {}
+
+  virtual ~RegAllocPriorityAdvisorProvider() = default;
+
+  virtual void logRewardIfNeeded(const MachineFunction &MF,
+                                 function_ref<float()> GetReward) {};
+
+  virtual std::unique_ptr<RegAllocPriorityAdvisor>
+  getAdvisor(const MachineFunction &MF, const RAGreedy &RA,
+             SlotIndexes *SI) = 0;
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arsenm wrote:

Make SI a reference, it is required 

https://github.com/llvm/llvm-project/pull/118462