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

[Matt Arsenault via llvm-commits]

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@@ -526,6 +531,19 @@ GCNScheduleDAGMILive::getRealRegPressure(unsigned RegionIdx) const {
   return RPTracker.moveMaxPressure();
 }
 
+static MachineInstr *getLastMIForRegion(MachineBasicBlock::iterator RegionBegin,
+                                        MachineBasicBlock::iterator RegionEnd) {
+  MachineInstr *LastMI;
+  auto *BB = RegionBegin->getParent();
+  if (RegionEnd != BB->end() && !RegionEnd->isDebugInstr())
+    LastMI = &*RegionEnd;
+  else if (RegionEnd == BB->end())
+    LastMI = &*prev_nodbg(RegionEnd, RegionBegin);
+  else
+    LastMI = &*skipDebugInstructionsBackward(RegionEnd, RegionBegin);
+  return LastMI;
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arsenm wrote:

I don't understand this function, this is all just the same thing as skipDebugInstructionsBackward?

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