[llvm] [VPlan] Replace VPRegionBlock with explicit CFG before execute (NFCI). (PR #117506)

[Florian Hahn via llvm-commits]

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@@ -2394,10 +2394,26 @@ void VPlanTransforms::createInterleaveGroups(
 
 void VPlanTransforms::convertToConcreteRecipes(VPlan &Plan,
                                                Type &CanonicalIVTy) {
+  // Replace loop regions with explicity CFG.
+  SmallVector<VPRegionBlock *> LoopRegions;
+  for (VPRegionBlock *R : VPBlockUtils::blocksOnly<VPRegionBlock>(
+           vp_depth_first_deep(Plan.getEntry()))) {
+    if (!R->isReplicator())
+      LoopRegions.push_back(R);
+  }
+  for (VPRegionBlock *R : LoopRegions) {
+    VPBlockBase *Header = R->getEntry();
+    VPBlockBase *Latch = R->getExiting();
+    R->removeRegion();
+    // Add explicit backedge.
+    VPBlockUtils::connectBlocks(Latch, Header);
+  }
+
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fhahn wrote:

Moved to separate function, thanks!

https://github.com/llvm/llvm-project/pull/117506