[NFC] Tweak SplitBlockAndInsertIfThen to use existing ThenBlock
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354107 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h
index 4e76328..e997ed0 100644
--- a/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -270,7 +270,8 @@
/// SplitBefore
/// Tail
///
-/// If Unreachable is true, then ThenBlock ends with
+/// If \p ThenBlock is not specified, a new block will be created for it.
+/// If \p Unreachable is true, the newly created block will end with
/// UnreachableInst, otherwise it branches to Tail.
/// Returns the NewBasicBlock's terminator.
///
@@ -279,7 +280,8 @@
bool Unreachable,
MDNode *BranchWeights = nullptr,
DominatorTree *DT = nullptr,
- LoopInfo *LI = nullptr);
+ LoopInfo *LI = nullptr,
+ BasicBlock *ThenBlock = nullptr);
/// SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen,
/// but also creates the ElseBlock.
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
index 5ca9222..6f49eae 100644
--- a/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -730,18 +730,23 @@
Instruction *SplitBefore,
bool Unreachable,
MDNode *BranchWeights,
- DominatorTree *DT, LoopInfo *LI) {
+ DominatorTree *DT, LoopInfo *LI,
+ BasicBlock *ThenBlock) {
BasicBlock *Head = SplitBefore->getParent();
BasicBlock *Tail = Head->splitBasicBlock(SplitBefore->getIterator());
Instruction *HeadOldTerm = Head->getTerminator();
LLVMContext &C = Head->getContext();
- BasicBlock *ThenBlock = BasicBlock::Create(C, "", Head->getParent(), Tail);
Instruction *CheckTerm;
- if (Unreachable)
- CheckTerm = new UnreachableInst(C, ThenBlock);
- else
- CheckTerm = BranchInst::Create(Tail, ThenBlock);
- CheckTerm->setDebugLoc(SplitBefore->getDebugLoc());
+ bool CreateThenBlock = (ThenBlock == nullptr);
+ if (CreateThenBlock) {
+ ThenBlock = BasicBlock::Create(C, "", Head->getParent(), Tail);
+ if (Unreachable)
+ CheckTerm = new UnreachableInst(C, ThenBlock);
+ else
+ CheckTerm = BranchInst::Create(Tail, ThenBlock);
+ CheckTerm->setDebugLoc(SplitBefore->getDebugLoc());
+ } else
+ CheckTerm = ThenBlock->getTerminator();
BranchInst *HeadNewTerm =
BranchInst::Create(/*ifTrue*/ThenBlock, /*ifFalse*/Tail, Cond);
HeadNewTerm->setMetadata(LLVMContext::MD_prof, BranchWeights);
@@ -756,7 +761,10 @@
DT->changeImmediateDominator(Child, NewNode);
// Head dominates ThenBlock.
- DT->addNewBlock(ThenBlock, Head);
+ if (CreateThenBlock)
+ DT->addNewBlock(ThenBlock, Head);
+ else
+ DT->changeImmediateDominator(ThenBlock, Head);
}
}
