[llvm] [AMDGPU] Optionally Use GCNRPTrackers during scheduling (PR #93090)

[Valery Pykhtin via llvm-commits]

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@@ -343,17 +407,47 @@ void GCNRPTracker::reset(const MachineInstr &MI,
   MaxPressure = CurPressure = getRegPressure(*MRI, LiveRegs);
 }
 
-////////////////////////////////////////////////////////////////////////////////
-// GCNUpwardRPTracker
-
-void GCNUpwardRPTracker::reset(const MachineRegisterInfo &MRI_,
-                               const LiveRegSet &LiveRegs_) {
+void GCNRPTracker::reset(const MachineRegisterInfo &MRI_,
+                         const LiveRegSet &LiveRegs_) {
   MRI = &MRI_;
   LiveRegs = LiveRegs_;
   LastTrackedMI = nullptr;
   MaxPressure = CurPressure = getRegPressure(MRI_, LiveRegs_);
 }
 
+void GCNRPTracker::bumpDeadDefs(ArrayRef<RegisterMaskPair> DeadDefs) {
+  for (const RegisterMaskPair &P : DeadDefs) {
+    Register Reg = P.RegUnit;
+    if (!Reg.isVirtual())
+      continue;
+    LaneBitmask LiveMask = LiveRegs[Reg];
+    LaneBitmask BumpedMask = LiveMask | P.LaneMask;
+    CurPressure.inc(Reg, LiveMask, BumpedMask, *MRI);
+  }
+  MaxPressure = max(MaxPressure, CurPressure);
+  for (const RegisterMaskPair &P : DeadDefs) {
+    Register Reg = P.RegUnit;
+    if (!Reg.isVirtual())
+      continue;
+    LaneBitmask LiveMask = LiveRegs[Reg];
+    LaneBitmask BumpedMask = LiveMask | P.LaneMask;
+    CurPressure.inc(Reg, BumpedMask, LiveMask, *MRI);
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vpykhtin wrote:

Is this just a way to restore CurPressure to the state is has been before bumpDeadDefs? Why not just copy CurPressure to a temp and update MaxPressure with the temp?

https://github.com/llvm/llvm-project/pull/93090