[llvm] [AMDGPU] Examine instructions in pending queues during scheduling (PR #147653)

[Matt Arsenault via llvm-commits]

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@@ -355,40 +392,74 @@ void GCNSchedStrategy::pickNodeFromQueue(SchedBoundary &Zone,
       // Initialize resource delta if needed in case future heuristics query it.
       if (TryCand.ResDelta == SchedResourceDelta())
         TryCand.initResourceDelta(Zone.DAG, SchedModel);
+      LLVM_DEBUG(printCandidateDecision(Cand, TryCand));
       Cand.setBest(TryCand);
-      LLVM_DEBUG(traceCandidate(Cand));
     }
+#ifndef NDEBUG
+    else
+      printCandidateDecision(TryCand, Cand);
+#endif
+  }
+
+  if (!shouldCheckPending(Zone, SchedModel))
+    return;
+
+  LLVM_DEBUG(dbgs() << "Pending Q:\n");
+  ReadyQueue &PQ = Zone.Pending;
+  for (SUnit *SU : PQ) {
+
+    SchedCandidate TryCand(ZonePolicy);
+    initCandidate(TryCand, SU, Zone.isTop(), RPTracker, SRI, SGPRPressure,
+                  VGPRPressure, IsBottomUp);
+    // Pass SchedBoundary only when comparing nodes from the same boundary.
+    SchedBoundary *ZoneArg = Cand.AtTop == TryCand.AtTop ? &Zone : nullptr;
+    tryPendingCandidate(Cand, TryCand, ZoneArg);
+    if (TryCand.Reason != NoCand) {
+      // Initialize resource delta if needed in case future heuristics query it.
+      if (TryCand.ResDelta == SchedResourceDelta())
+        TryCand.initResourceDelta(Zone.DAG, SchedModel);
+      LLVM_DEBUG(printCandidateDecision(Cand, TryCand));
+      IsPending = true;
+      Cand.setBest(TryCand);
+    }
+#ifndef NDEBUG
+    else
+      printCandidateDecision(TryCand, Cand);
+#endif
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arsenm wrote:

Don't have a macro conditional  else 

https://github.com/llvm/llvm-project/pull/147653