[llvm-branch-commits] [llvm] [AMDGPU] Physical register tracking in GCN trackers. (PR #184275)

[Matt Arsenault via llvm-branch-commits]

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@@ -320,12 +320,47 @@ class GCNRPTracker {
 
 protected:
   const LiveIntervals &LIS;
+
+  // Virtual register tracking
   LiveRegSet VirtLiveRegs;
   GCNRegPressure CurVirtPressure, MaxVirtPressure;
+
+  // Physical register tracking: Maintain clean separation between virtual and
+  // physical registers. Tracking physical registers can be turned OFF with an
+  // option. Using llvm::LiveRegSet for consistency with the generic tracker.
+  llvm::LiveRegSet PhysLiveRegs;
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arsenm wrote:

I don't really understand this handling. You're tracking all the regunits, and managing lane masks? The live regunits is a single bit vector 

https://github.com/llvm/llvm-project/pull/184275