Vendor import of stripped llvm trunk r375505, the last commit before thevendor/llvm/llvm-trunk-r375505vendor/llvm

upstream Subversion repository was made read-only, and the LLVM project
migrated to GitHub:

https://llvm.org/svn/llvm-project/llvm/trunk@375505

1 files changed, 9 insertions, 2 deletions

diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h
index 4d861ffe9a31..698e57fd0394 100644
--- a/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -83,10 +83,16 @@ bool DeleteDeadPHIs(BasicBlock *BB, const TargetLibraryInfo *TLI = nullptr);
 
 /// Attempts to merge a block into its predecessor, if possible. The return
 /// value indicates success or failure.
+/// By default do not merge blocks if BB's predecessor has multiple successors.
+/// If PredecessorWithTwoSuccessors = true, the blocks can only be merged
+/// if BB's Pred has a branch to BB and to AnotherBB, and BB has a single
+/// successor Sing. In this case the branch will be updated with Sing instead of
+/// BB, and BB will still be merged into its predecessor and removed.
 bool MergeBlockIntoPredecessor(BasicBlock *BB, DomTreeUpdater *DTU = nullptr,
                                LoopInfo *LI = nullptr,
                                MemorySSAUpdater *MSSAU = nullptr,
-                               MemoryDependenceResults *MemDep = nullptr);
+                               MemoryDependenceResults *MemDep = nullptr,
+                               bool PredecessorWithTwoSuccessors = false);
 
 /// Replace all uses of an instruction (specified by BI) with a value, then
 /// remove and delete the original instruction.
@@ -222,7 +228,8 @@ BasicBlock *SplitEdge(BasicBlock *From, BasicBlock *To,
 /// info is updated.
 BasicBlock *SplitBlock(BasicBlock *Old, Instruction *SplitPt,
                        DominatorTree *DT = nullptr, LoopInfo *LI = nullptr,
-                       MemorySSAUpdater *MSSAU = nullptr);
+                       MemorySSAUpdater *MSSAU = nullptr,
+                       const Twine &BBName = "");
 
 /// This method introduces at least one new basic block into the function and
 /// moves some of the predecessors of BB to be predecessors of the new block.