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

[Valery Pykhtin via llvm-commits]

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@@ -213,8 +242,15 @@ void GCNSchedStrategy::pickNodeFromQueue(SchedBoundary &Zone,
   unsigned SGPRPressure = 0;
   unsigned VGPRPressure = 0;
   if (DAG->isTrackingPressure()) {
-    SGPRPressure = Pressure[AMDGPU::RegisterPressureSets::SReg_32];
-    VGPRPressure = Pressure[AMDGPU::RegisterPressureSets::VGPR_32];
+    SGPRPressure =
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vpykhtin wrote:

This is hard to read. Can you do something like:

```
 if (!GCNTrackers) {
    // old code
 }  else {
    GCNRPTracker *T  = isTop? &DownwardTracker : &UpwardTracker;
    ... = T->getPressure().getVGPRNum(false);
    ... = T->getPressure().getSGPRNum();
 }
```

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