[NFC] Add parameter for keeping one-input Phis in DeleteDeadBlock(s)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353799 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 4 deletions

diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h
index fad01f6e8b3..c264aaee70d 100644
--- a/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -41,19 +41,25 @@ class Value;
 
 /// Replace contents of every block in \p BBs with single unreachable
 /// instruction. If \p Updates is specified, collect all necessary DT updates
-/// into this vector.
+/// into this vector. If \p DontDeleteUselessPHIs is true, one-input Phis in
+/// successors of blocks being deleted will be preserved.
 void DetatchDeadBlocks(ArrayRef <BasicBlock *> BBs,
-                       SmallVectorImpl<DominatorTree::UpdateType> *Updates);
+                       SmallVectorImpl<DominatorTree::UpdateType> *Updates,
+                       bool DontDeleteUselessPHIs = false);
 
 /// Delete the specified block, which must have no predecessors.
-void DeleteDeadBlock(BasicBlock *BB, DomTreeUpdater *DTU = nullptr);
+void DeleteDeadBlock(BasicBlock *BB, DomTreeUpdater *DTU = nullptr,
+                     bool DontDeleteUselessPHIs = false);
 
 /// Delete the specified blocks from \p BB. The set of deleted blocks must have
 /// no predecessors that are not being deleted themselves. \p BBs must have no
 /// duplicating blocks. If there are loops among this set of blocks, all
 /// relevant loop info updates should be done before this function is called.
+/// If \p DontDeleteUselessPHIs is true, one-input Phis in successors of blocks
+/// being deleted will be preserved.
 void DeleteDeadBlocks(ArrayRef <BasicBlock *> BBs,
-                      DomTreeUpdater *DTU = nullptr);
+                      DomTreeUpdater *DTU = nullptr,
+                      bool DontDeleteUselessPHIs = false);
 
 /// We know that BB has one predecessor. If there are any single-entry PHI nodes
 /// in it, fold them away. This handles the case when all entries to the PHI