[llvm] [AMDGPU][SIInsertWaitCnts] Use RegUnits-based tracking (PR #162077)

[Matt Arsenault via llvm-commits]

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@@ -752,15 +781,26 @@ class WaitcntBrackets {
       ScoreLBs[EXP_CNT] = ScoreUBs[EXP_CNT] - Context->getWaitCountMax(EXP_CNT);
   }
 
-  void setRegScore(int GprNo, InstCounterType T, unsigned Val) {
-    setScoreByInterval({GprNo, GprNo + 1}, T, Val);
+  void setRegScore(MCPhysReg Reg, InstCounterType T, unsigned Val) {
+    const SIRegisterInfo *TRI = Context->TRI;
+    if (Reg == AMDGPU::SCC) {
+      SCCScore = Val;
+    } else if (TRI->isVectorRegister(*Context->MRI, Reg)) {
+      for (MCRegUnit RU : regunits(Reg))
+        VMem[toVMEMID(RU)].Scores[T] = Val;
+    } else if (TRI->isSGPRReg(*Context->MRI, Reg)) {
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arsenm wrote:

Can't this be else if (isSGPR()) else { }? There aren't registers that are something else? 

https://github.com/llvm/llvm-project/pull/162077