[llvm] [SandboxVec][DAG] Implement UnscheduledSuccs (PR #112255)

[Sriraman Tallam via llvm-commits]

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@@ -215,6 +211,51 @@ void DependencyGraph::scanAndAddDeps(MemDGNode &DstN,
   }
 }
 
+void DependencyGraph::setDefUseUnscheduledSuccs(
+    const Interval<Instruction> &NewInterval) {
+  // Set the intra-interval counters in NewInterval.
+  for (Instruction &I : NewInterval) {
+    for (Value *Op : I.operands()) {
+      auto *OpI = dyn_cast<Instruction>(Op);
+      if (OpI == nullptr)
+        continue;
+      // TODO: Check if OpI is in NewInterval to save compile time?
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tmsri wrote:

This TODO seems important and as the code below is inefficient otherwise?

https://github.com/llvm/llvm-project/pull/112255