Refactor UpdatePredRedefs and StepForward to avoid duplication. NFC

[oota-llvm.git] / include / llvm / CodeGen / MachineDominators.h

diff --git a/include/llvm/CodeGen/MachineDominators.h b/include/llvm/CodeGen/MachineDominators.h
index 879ae86151092ec8b13e0bfe7cc2cd1ecfd046d2..4428fa618fb01e6f08e79d0af1a69edfbefa1384 100644 (file)
--- a/include/llvm/CodeGen/MachineDominators.h
+++ b/include/llvm/CodeGen/MachineDominators.h
@@ -45,9 +45,6 @@ class MachineDominatorTree : public MachineFunctionPass {
     MachineBasicBlock *FromBB;
     MachineBasicBlock *ToBB;
     MachineBasicBlock *NewBB;
-    CriticalEdge(MachineBasicBlock *FromBB, MachineBasicBlock *ToBB,
-                 MachineBasicBlock *NewBB)
-        : FromBB(FromBB), ToBB(ToBB), NewBB(NewBB) {}
   };
 
   /// \brief Pile up all the critical edges to be split.
@@ -67,74 +64,7 @@ class MachineDominatorTree : public MachineFunctionPass {
   /// the fast query path of DT as much as possible.
   ///
   /// \post CriticalEdgesToSplit.empty().
-  void applySplitCriticalEdges() const {
-    // Bail out early if there is nothing to do.
-    if (CriticalEdgesToSplit.empty())
-      return;
-
-    // For each element in CriticalEdgesToSplit, remember whether or
-    // not element is the new immediate domminator of its successor.
-    // The mapping is done by index, i.e., the information for the ith
-    // element of CriticalEdgesToSplit is the ith element of IsNewIDom.
-    SmallVector<bool, 32> IsNewIDom;
-    IsNewIDom.resize(CriticalEdgesToSplit.size());
-    size_t Idx = 0;
-
-    // Collect all the dominance properties info, before invalidating
-    // the underlying DT.
-    for (CriticalEdge &Edge : CriticalEdgesToSplit) {
-      // Update dominator information.
-      MachineBasicBlock *Succ = Edge.ToBB;
-      MachineDomTreeNode *SucccDTNode = DT->getNode(Succ);
-
-      IsNewIDom[Idx] = true;
-      for (MachineBasicBlock *PredBB : Succ->predecessors()) {
-        if (PredBB == Edge.NewBB)
-          continue;
-        // If we are in this situation:
-        // FromBB1        FromBB2
-        //    +              +
-        //   + +            + +
-        //  +   +          +   +
-        // ...  Split1  Split2 ...
-        //           +   +
-        //            + +
-        //             +
-        //            Succ
-        // Instead of checking the domiance property with Split2, we
-        // check it with FromBB2 since Split2 is still unknown of the
-        // underlying DT structure.
-        if (NewBBs.count(PredBB)) {
-          assert(PredBB->pred_size() == 1 && "A basic block resulting from a "
-                                             "critical edge split has more "
-                                             "than one predecessor!");
-          PredBB = *PredBB->pred_begin();
-        }
-        if (!DT->dominates(SucccDTNode, DT->getNode(PredBB))) {
-          IsNewIDom[Idx] = false;
-          break;
-        }
-      }
-      ++Idx;
-    }
-
-    // Now, update DT with the collected dominance properties info.
-    Idx = 0;
-    for (CriticalEdge &Edge : CriticalEdgesToSplit) {
-      // We know FromBB dominates NewBB.
-      MachineDomTreeNode *NewDTNode = DT->addNewBlock(Edge.NewBB, Edge.FromBB);
-      MachineDomTreeNode *SucccDTNode = DT->getNode(Edge.ToBB);
-
-      // If all the other predecessors of "Succ" are dominated by "Succ" itself
-      // then the new block is the new immediate dominator of "Succ". Otherwise,
-      // the new block doesn't dominate anything.
-      if (IsNewIDom[Idx])
-        DT->changeImmediateDominator(SucccDTNode, NewDTNode);
-      ++Idx;
-    }
-    NewBBs.clear();
-    CriticalEdgesToSplit.clear();
-  }
+  void applySplitCriticalEdges() const;
 
 public:
   static char ID; // Pass ID, replacement for typeid
@@ -142,7 +72,7 @@ public:
 
   MachineDominatorTree();
 
-  ~MachineDominatorTree();
+  ~MachineDominatorTree() override;
 
   DominatorTreeBase<MachineBasicBlock> &getBase() {
     applySplitCriticalEdges();
@@ -303,11 +233,11 @@ public:
   void recordSplitCriticalEdge(MachineBasicBlock *FromBB,
                               MachineBasicBlock *ToBB,
                               MachineBasicBlock *NewBB) {
-    bool Inserted = NewBBs.insert(NewBB);
+    bool Inserted = NewBBs.insert(NewBB).second;
     (void)Inserted;
     assert(Inserted &&
            "A basic block inserted via edge splitting cannot appear twice");
-    CriticalEdgesToSplit.push_back(CriticalEdge(FromBB, ToBB, NewBB));
+    CriticalEdgesToSplit.push_back({FromBB, ToBB, NewBB});
   }
 };