Revert "[CHR] Fix up phi nodes with unreachable predecessors (PR64594)"

This reverts commit cfc9298dc588c626a52193260da28a630e103916.

The newly added test fails under EXPENSIVE_CHECKS, revert while I
investigate.

1 files changed, 0 insertions, 15 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
index 478e45b..3e3be53 100644
--- a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
@@ -1777,21 +1777,6 @@ void CHR::cloneScopeBlocks(CHRScope *Scope,
       BasicBlock *NewBB = CloneBasicBlock(BB, VMap, ".nonchr", &F);
       NewBlocks.push_back(NewBB);
       VMap[BB] = NewBB;
-
-      // Unreachable predecessors will not be cloned and will not have an edge
-      // to the cloned block. As such, also remove them from any phi nodes.
-      // To avoid iterator invalidation, first collect the dead predecessors
-      // from the first phi node, and then perform the actual removal.
-      SmallVector<BasicBlock *> DeadPreds;
-      for (PHINode &PN : NewBB->phis()) {
-        for (BasicBlock *Pred : PN.blocks())
-          if (!DT.isReachableFromEntry(Pred))
-            DeadPreds.push_back(Pred);
-        break;
-      }
-      for (PHINode &PN : make_early_inc_range(NewBB->phis()))
-        for (BasicBlock *Pred : DeadPreds)
-          PN.removeIncomingValue(Pred);
     }
 
   // Place the cloned blocks right after the original blocks (right before the