+
+ // Unconditionally connect split block to its remaining successor.
+ BranchInst *SplitTerminator =
+ cast<BranchInst>(SplitCondBlock->getTerminator());
+ BasicBlock *Succ0 = SplitTerminator->getSuccessor(0);
+ BasicBlock *Succ1 = SplitTerminator->getSuccessor(1);
+ if (Succ0 == ExitCondition->getParent())
+ SplitTerminator->setUnconditionalDest(Succ1);
+ else
+ SplitTerminator->setUnconditionalDest(Succ0);
+
+ // Remove split condition.
+ SD.SplitCondition->eraseFromParent();
+ if (Op0->use_begin() == Op0->use_end())
+ Op0->eraseFromParent();
+ if (Op1->use_begin() == Op1->use_end())
+ Op1->eraseFromParent();
+
+ BranchInst *ExitInsn =
+ dyn_cast<BranchInst>(ExitingBlock->getTerminator());
+ assert (ExitInsn && "Unable to find suitable loop exit branch");
+ BasicBlock *ExitBlock = ExitInsn->getSuccessor(1);
+ if (L->contains(ExitBlock))
+ ExitBlock = ExitInsn->getSuccessor(0);
+
+ // Update domiantor info. Now, ExitingBlock has only one predecessor,
+ // ExitingBBPred, and it is ExitingBlock's immediate domiantor.
+ DT->changeImmediateDominator(ExitingBlock, ExitingBBPred);
+
+ // If ExitingBlock is a member of loop BB's DF list then replace it with
+ // loop header and exit block.
+ for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
+ I != E; ++I) {
+ BasicBlock *BB = *I;
+ if (BB == Header || BB == ExitingBlock)
+ continue;
+ DominanceFrontier::iterator BBDF = DF->find(BB);
+ DominanceFrontier::DomSetType::iterator DomSetI = BBDF->second.begin();
+ DominanceFrontier::DomSetType::iterator DomSetE = BBDF->second.end();
+ while (DomSetI != DomSetE) {
+ DominanceFrontier::DomSetType::iterator CurrentItr = DomSetI;
+ ++DomSetI;
+ BasicBlock *DFBB = *CurrentItr;
+ if (DFBB == ExitingBlock) {
+ BBDF->second.erase(DFBB);
+ BBDF->second.insert(Header);
+ if (Header != ExitingBlock)
+ BBDF->second.insert(ExitBlock);
+ }
+ }
+ }
+
+ return true;