[llvm] c4d84e1 - [VPlan] Use replaceSuccessor/replacePredecessor in insertBlock (NFC).

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2025-04-25T20:46:10+01:00
New Revision: c4d84e1b0021a231898cb0325db4f9687908dd82

URL: https://github.com/llvm/llvm-project/commit/c4d84e1b0021a231898cb0325db4f9687908dd82
DIFF: https://github.com/llvm/llvm-project/commit/c4d84e1b0021a231898cb0325db4f9687908dd82.diff

LOG: [VPlan] Use replaceSuccessor/replacePredecessor in insertBlock (NFC).

Use replaceSuccessor/replacePredecessor in
insertBlockAfter/insertBlockBefore. This preserves the predecessor
order, which in turns is needed to not invalidate existing phi recipes.

At the moment this is NFC, but enables additional uses in the future.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlanUtils.h

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/VPlanUtils.h b/llvm/lib/Transforms/Vectorize/VPlanUtils.h
index 51c53196a1141..b0dc2398ea8c4 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanUtils.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanUtils.h
@@ -90,9 +90,10 @@ class VPBlockUtils {
     NewBlock->setParent(BlockPtr->getParent());
     SmallVector<VPBlockBase *> Succs(BlockPtr->successors());
     for (VPBlockBase *Succ : Succs) {
-      disconnectBlocks(BlockPtr, Succ);
-      connectBlocks(NewBlock, Succ);
+      Succ->replacePredecessor(BlockPtr, NewBlock);
+      NewBlock->appendSuccessor(Succ);
     }
+    BlockPtr->clearSuccessors();
     connectBlocks(BlockPtr, NewBlock);
   }
 
@@ -106,9 +107,10 @@ class VPBlockUtils {
            "Can't insert new block with predecessors or successors.");
     NewBlock->setParent(BlockPtr->getParent());
     for (VPBlockBase *Pred : to_vector(BlockPtr->predecessors())) {
-      disconnectBlocks(Pred, BlockPtr);
-      connectBlocks(Pred, NewBlock);
+      Pred->replaceSuccessor(BlockPtr, NewBlock);
+      NewBlock->appendPredecessor(Pred);
     }
+    BlockPtr->clearPredecessors();
     connectBlocks(NewBlock, BlockPtr);
   }