[AMDGPU][SIInsertWaitcnts][NFC] SGPRInfo: Move score selection logic closer (#186518)

vporpo · web-flow · commit 368f38b9fcfe · 2026-03-20T16:30:52.000-07:00
Selecting the score in SGPRInfo used to require an index which you would
get by calling a getSgprScoresIdx(), which is defined in a different
class.

This patch moves the score selection logic into the SGPRinfo. This makes
the interface simpler and more intuitive.

Also given that SGPRInfo contains only two scores, this patch also
replaces the score array with individual score variables.

Should be NFC.
diff --git a/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp b/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
@@ -721,11 +721,6 @@ class WaitcntBrackets {
     return T == Context->SmemAccessCounter || T == X_CNT;
   }
 
-  unsigned getSgprScoresIdx(InstCounterType T) const {
-    assert(isSmemCounter(T) && "Invalid SMEM counter");
-    return T == X_CNT ? 1 : 0;
-  }
-
   unsigned getOutstanding(InstCounterType T) const {
     return ScoreUBs[T] - ScoreLBs[T];
   }
@@ -754,7 +749,7 @@ class WaitcntBrackets {
 
   unsigned getSGPRScore(MCRegUnit RU, InstCounterType T) const {
     auto It = SGPRs.find(RU);
-    return It != SGPRs.end() ? It->second.Scores[getSgprScoresIdx(T)] : 0;
+    return It != SGPRs.end() ? It->second.get(T) : 0;
   }
 
   unsigned getVMemScore(VMEMID TID, InstCounterType T) const {
@@ -927,9 +922,8 @@ class WaitcntBrackets {
       for (MCRegUnit RU : regunits(Reg))
         VMem[toVMEMID(RU)].Scores[T] = Val;
     } else if (TRI.isSGPRReg(Context->MRI, Reg)) {
-      auto STy = getSgprScoresIdx(T);
       for (MCRegUnit RU : regunits(Reg))
-        SGPRs[RU].Scores[STy] = Val;
+        SGPRs[RU].get(T) = Val;
     } else {
       llvm_unreachable("Register cannot be tracked/unknown register!");
     }
@@ -974,14 +968,24 @@ class WaitcntBrackets {
     bool empty() const { return all_of(Scores, equal_to(0)) && !VMEMTypes; }
   };
 
-  struct SGPRInfo {
-    // Wait cnt scores for every sgpr, the DS_CNT (corresponding to LGKMcnt
-    // pre-gfx12) or KM_CNT (gfx12+ only), and X_CNT (gfx1250) are relevant.
-    // Row 0 represents the score for either DS_CNT or KM_CNT and row 1 keeps
-    // the X_CNT score.
-    std::array<unsigned, 2> Scores = {0};
+  /// Wait cnt scores for every sgpr, the DS_CNT (corresponding to LGKMcnt
+  /// pre-gfx12) or KM_CNT (gfx12+ only), and X_CNT (gfx1250) are relevant.
+  class SGPRInfo {
+    /// Either DS_CNT or KM_CNT score.
+    unsigned ScoreDsKmCnt = 0;
+    unsigned ScoreXCnt = 0;
+
+  public:
+    unsigned get(InstCounterType T) const {
+      assert((T == DS_CNT || T == KM_CNT || T == X_CNT) && "Invalid counter");
+      return T == X_CNT ? ScoreXCnt : ScoreDsKmCnt;
+    }
+    unsigned &get(InstCounterType T) {
+      assert((T == DS_CNT || T == KM_CNT || T == X_CNT) && "Invalid counter");
+      return T == X_CNT ? ScoreXCnt : ScoreDsKmCnt;
+    }
 
-    bool empty() const { return !Scores[0] && !Scores[1]; }
+    bool empty() const { return !ScoreDsKmCnt && !ScoreXCnt; }
   };
 
   DenseMap<VMEMID, VMEMInfo> VMem; // VGPR + LDS DMA
@@ -1359,7 +1363,7 @@ void WaitcntBrackets::print(raw_ostream &OS) const {
         SmallVector<MCRegUnit> SortedSMEMIDs(SGPRs.keys());
         sort(SortedSMEMIDs);
         for (auto ID : SortedSMEMIDs) {
-          unsigned RegScore = SGPRs.at(ID).Scores[getSgprScoresIdx(T)];
+          unsigned RegScore = SGPRs.at(ID).get(T);
           if (RegScore <= LB)
             continue;
           unsigned RelScore = RegScore - LB - 1;
@@ -3089,12 +3093,10 @@ bool WaitcntBrackets::merge(const WaitcntBrackets &Other) {
       StrictDom |= mergeScore(M, Info.Scores[T], Other.getVMemScore(RegID, T));
 
     if (isSmemCounter(T)) {
-      unsigned Idx = getSgprScoresIdx(T);
       for (auto &[RegID, Info] : SGPRs) {
         auto It = Other.SGPRs.find(RegID);
-        unsigned OtherScore =
-            (It != Other.SGPRs.end()) ? It->second.Scores[Idx] : 0;
-        StrictDom |= mergeScore(M, Info.Scores[Idx], OtherScore);
+        unsigned OtherScore = (It != Other.SGPRs.end()) ? It->second.get(T) : 0;
+        StrictDom |= mergeScore(M, Info.get(T), OtherScore);
       }
     }
   }
