[llvm] [AMDGPU] NFC: Add BBLiveOutMap & LiveOut Cache (PR #93089)

[Matt Arsenault via llvm-commits]

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@@ -613,7 +627,37 @@ GCNScheduleDAGMILive::getBBLiveInMap() const {
       ++I;
     } while (I != E && I->first->getParent() == BB);
   } while (I != E);
-  return getLiveRegMap(BBStarters, false /*After*/, *LIS);
+  return getLiveRegMap(BBStarters, /*After=*/false, *LIS);
+}
+
+DenseMap<MachineInstr *, GCNRPTracker::LiveRegSet>
+GCNScheduleDAGMILive::getBBLiveOutMap() const {
+  assert(!Regions.empty());
+  std::vector<MachineInstr *> BBEnders;
+  BBEnders.reserve(Regions.size());
+  auto I = Regions.rbegin(), E = Regions.rend();
+  for (; I != E; I++)
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arsenm wrote:

for (auto [FirstName, SecondName] : reverse(Regions)) 

https://github.com/llvm/llvm-project/pull/93089