Move SplitBlockAndInsertIfThen to BasicBlockUtils.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166278 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
index edeebe1..9fea113 100644
--- a/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -687,3 +687,42 @@
return cast<ReturnInst>(NewRet);
}
+/// 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 *llvm::SplitBlockAndInsertIfThen(Instruction *Cmp,
+ bool Unreachable, MDNode *BranchWeights) {
+ Instruction *SplitBefore = Cmp->getNextNode();
+ BasicBlock *Head = SplitBefore->getParent();
+ BasicBlock *Tail = Head->splitBasicBlock(SplitBefore);
+ TerminatorInst *HeadOldTerm = Head->getTerminator();
+ LLVMContext &C = Head->getContext();
+ BasicBlock *ThenBlock = BasicBlock::Create(C, "", Head->getParent(), Tail);
+ TerminatorInst *CheckTerm;
+ if (Unreachable)
+ CheckTerm = new UnreachableInst(C, ThenBlock);
+ else
+ CheckTerm = BranchInst::Create(Tail, ThenBlock);
+ BranchInst *HeadNewTerm =
+ BranchInst::Create(/*ifTrue*/ThenBlock, /*ifFalse*/Tail, Cmp);
+ HeadNewTerm->setMetadata(LLVMContext::MD_prof, BranchWeights);
+ ReplaceInstWithInst(HeadOldTerm, HeadNewTerm);
+ return CheckTerm;
+}