Move SplitBlockAndInsertIfThen to BasicBlockUtils.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166278 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/Utils/BasicBlockUtils.h

@@ -25,9 +25,11 @@ namespace llvm {
 
 class AliasAnalysis;
 class Instruction;
+class MDNode;
 class Pass;
 class ReturnInst;
 class TargetLibraryInfo;
+class TerminatorInst;
 
 /// DeleteDeadBlock - Delete the specified block, which must have no
 /// predecessors.
@@ -203,6 +205,29 @@ void SplitLandingPadPredecessors(BasicBlock *OrigBB,ArrayRef<BasicBlock*> Preds,
 ReturnInst *FoldReturnIntoUncondBranch(ReturnInst *RI, BasicBlock *BB,
                                        BasicBlock *Pred);
 
+/// SplitBlockAndInsertIfThen - Split the containing block at the
+/// specified instruction - everything before and including Cmp stays
+/// in the old basic block, and everything after Cmp is moved to a
+/// new block. The two blocks are connected by a conditional branch
+/// (with value of Cmp being the condition).
+/// Before:
+///   Head
+///   Cmp
+///   Tail
+/// After:
+///   Head
+///   Cmp
+///   if (Cmp)
+///     ThenBlock
+///   Tail
+///
+/// If Unreachable is true, then ThenBlock ends with
+/// UnreachableInst, otherwise it branches to Tail.
+/// Returns the NewBasicBlock's terminator.
+
+TerminatorInst *SplitBlockAndInsertIfThen(Instruction *Cmp,
+    bool Unreachable, MDNode *BranchWeights = 0);
+
 } // End llvm namespace
 
 #endif