[LLVM] [RegionInfo] Introduce getExitingBlocks to get all predecessors of Exit in the current region.

[etherzhhb]

Summary

This function will return true if all predecessors of Exit are in the current region, false otherwise.

[grosser]

LGTM. Thanks for the contribution.

include/llvm/Analysis/RegionInfo.h

402 ↗

(On Diff #109275)

blocks

[grosser]

Hi ether, any plans to commit this?

llvm/trunk/include/llvm/Analysis/RegionInfo.h

public:
 
   /// @brief Return the first block of this region's single exit edge,
   ///        if existing.
   ///
   /// @return The BasicBlock starting this region's single exit edge,
   ///         else NULL.
   BlockT *getExitingBlock() const;
 
+  /// @brief Collect all blocks of this region's single exit edge, if existing.
+  ///
+  /// @return True if this region contains all the predecessors of the exit.
+  bool getExitingBlocks(SmallVectorImpl<BlockT *> &Exitings) const;
+
   /// @brief Is this a simple region?
   ///
   /// A region is simple if it has exactly one exit and one entry edge.
   ///
   /// @return True if the Region is simple.
   bool isSimple() const;
 
   /// @brief Returns the name of the Region.

llvm/trunk/include/llvm/Analysis/RegionInfoImpl.h

if (DT->getNode(Pred) && !contains(Pred)) {
       enteringBlock = Pred;
     }
   }
 
   return enteringBlock;
 }
 
 template <class Tr>
+bool RegionBase<Tr>::getExitingBlocks(
+    SmallVectorImpl<BlockT *> &Exitings) const {
+  bool CoverAll = true;
+
+  if (!exit)
+    return CoverAll;
+
+  for (PredIterTy PI = InvBlockTraits::child_begin(exit),
+                  PE = InvBlockTraits::child_end(exit);
+       PI != PE; ++PI) {
+    BlockT *Pred = *PI;
+    if (contains(Pred)) {
+      Exitings.push_back(Pred);
+      continue;
+    }
+
+    CoverAll = false;
+  }
+
+  return CoverAll;
+}
+
+template <class Tr>
 typename RegionBase<Tr>::BlockT *RegionBase<Tr>::getExitingBlock() const {
   BlockT *exit = getExit();
   BlockT *exitingBlock = nullptr;
 
   if (!exit)
     return nullptr;
 
   for (BlockT *Pred : make_range(InvBlockTraits::child_begin(exit),