+
+/// SplitEdge - Split the edge connecting specified block. Pass P must
+/// not be NULL.
+BasicBlock *SplitEdge(BasicBlock *From, BasicBlock *To, Pass *P);
+
+/// SplitBlock - Split the specified block at the specified instruction - every
+/// thing before SplitPt stays in Old and everything starting with SplitPt moves
+/// to a new block. The two blocks are joined by an unconditional branch and
+/// the loop info is updated.
+///
+BasicBlock *SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P);
+
+/// SplitBlockPredecessors - This method transforms BB by introducing a new
+/// basic block into the function, and moving some of the predecessors of BB to
+/// be predecessors of the new block. The new predecessors are indicated by the
+/// Preds array, which has NumPreds elements in it. The new block is given a
+/// suffix of 'Suffix'. This function returns the new block.
+///
+/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
+/// DominanceFrontier, LoopInfo, and LCCSA but no other analyses.
+/// In particular, it does not preserve LoopSimplify (because it's
+/// complicated to handle the case where one of the edges being split
+/// is an exit of a loop with other exits).
+///
+BasicBlock *SplitBlockPredecessors(BasicBlock *BB, ArrayRef<BasicBlock*> Preds,
+ const char *Suffix, Pass *P = nullptr);
+
+/// SplitLandingPadPredecessors - This method transforms the landing pad,
+/// OrigBB, by introducing two new basic blocks into the function. One of those
+/// new basic blocks gets the predecessors listed in Preds. The other basic
+/// block gets the remaining predecessors of OrigBB. The landingpad instruction
+/// OrigBB is clone into both of the new basic blocks. The new blocks are given
+/// the suffixes 'Suffix1' and 'Suffix2', and are returned in the NewBBs vector.
+///
+/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
+/// DominanceFrontier, LoopInfo, and LCCSA but no other analyses. In particular,
+/// it does not preserve LoopSimplify (because it's complicated to handle the
+/// case where one of the edges being split is an exit of a loop with other
+/// exits).
+///
+void SplitLandingPadPredecessors(BasicBlock *OrigBB,ArrayRef<BasicBlock*> Preds,
+ const char *Suffix, const char *Suffix2,
+ Pass *P, SmallVectorImpl<BasicBlock*> &NewBBs);
+
+/// FoldReturnIntoUncondBranch - This method duplicates the specified return
+/// instruction into a predecessor which ends in an unconditional branch. If
+/// the return instruction returns a value defined by a PHI, propagate the
+/// right value into the return. It returns the new return instruction in the
+/// predecessor.
+ReturnInst *FoldReturnIntoUncondBranch(ReturnInst *RI, BasicBlock *BB,
+ BasicBlock *Pred);
+
+/// SplitBlockAndInsertIfThen - Split the containing block at the
+/// specified instruction - everything before and including SplitBefore stays
+/// in the old basic block, and everything after SplitBefore is moved to a
+/// new block. The two blocks are connected by a conditional branch
+/// (with value of Cmp being the condition).
+/// Before:
+/// Head
+/// SplitBefore
+/// Tail
+/// After:
+/// Head
+/// if (Cond)
+/// ThenBlock
+/// SplitBefore
+/// Tail
+///
+/// If Unreachable is true, then ThenBlock ends with
+/// UnreachableInst, otherwise it branches to Tail.
+/// Returns the NewBasicBlock's terminator.
+///
+/// Updates DT if given.
+TerminatorInst *SplitBlockAndInsertIfThen(Value *Cond, Instruction *SplitBefore,
+ bool Unreachable,
+ MDNode *BranchWeights = nullptr,
+ DominatorTree *DT = nullptr);
+
+/// SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen,
+/// but also creates the ElseBlock.
+/// Before:
+/// Head
+/// SplitBefore
+/// Tail
+/// After:
+/// Head
+/// if (Cond)
+/// ThenBlock
+/// else
+/// ElseBlock
+/// SplitBefore
+/// Tail
+void SplitBlockAndInsertIfThenElse(Value *Cond, Instruction *SplitBefore,
+ TerminatorInst **ThenTerm,
+ TerminatorInst **ElseTerm,
+ MDNode *BranchWeights = nullptr);
+
+///
+/// GetIfCondition - Check whether BB is the merge point of a if-region.
+/// If so, return the boolean condition that determines which entry into
+/// BB will be taken. Also, return by references the block that will be
+/// entered from if the condition is true, and the block that will be
+/// entered if the condition is false.
+Value *GetIfCondition(BasicBlock *BB, BasicBlock *&IfTrue,
+ BasicBlock *&IfFalse);