diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -574,9 +574,9 @@
   // Place the block after the current block, if possible, or else at
   // the end of the function.
   if (CurBB && CurBB->getParent())
-    CurFn->getBasicBlockList().insertAfter(CurBB->getIterator(), BB);
+    CurFn->insertBasicBlockAt(std::next(CurBB->getIterator()), BB);
   else
-    CurFn->getBasicBlockList().push_back(BB);
+    CurFn->insertBasicBlockAt(CurFn->end(), BB);
   Builder.SetInsertPoint(BB);
 }
 
@@ -601,15 +601,15 @@
   bool inserted = false;
   for (llvm::User *u : block->users()) {
     if (llvm::Instruction *insn = dyn_cast<llvm::Instruction>(u)) {
-      CurFn->getBasicBlockList().insertAfter(insn->getParent()->getIterator(),
-                                             block);
+      CurFn->insertBasicBlockAt(std::next(insn->getParent()->getIterator()),
+                                block);
       inserted = true;
       break;
     }
   }
 
   if (!inserted)
-    CurFn->getBasicBlockList().push_back(block);
+    CurFn->insertBasicBlockAt(CurFn->end(), block);
 
   Builder.SetInsertPoint(block);
 }
@@ -1469,7 +1469,7 @@
   llvm::BasicBlock *FalseDest = CaseRangeBlock;
   CaseRangeBlock = createBasicBlock("sw.caserange");
 
-  CurFn->getBasicBlockList().push_back(CaseRangeBlock);
+  CurFn->insertBasicBlockAt(CurFn->end(), CaseRangeBlock);
   Builder.SetInsertPoint(CaseRangeBlock);
 
   // Emit range check.
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -319,8 +319,10 @@
 
 static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) {
   if (!BB) return;
-  if (!BB->use_empty())
-    return CGF.CurFn->getBasicBlockList().push_back(BB);
+  if (!BB->use_empty()) {
+    CGF.CurFn->insertBasicBlockAt(CGF.CurFn->end(), BB);
+    return;
+  }
   delete BB;
 }
 
diff --git a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp
--- a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp
+++ b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp
@@ -863,7 +863,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -875,7 +875,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter2/toy.cpp b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter2/toy.cpp
--- a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter2/toy.cpp
+++ b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter2/toy.cpp
@@ -863,7 +863,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -875,7 +875,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter3/toy.cpp b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter3/toy.cpp
--- a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter3/toy.cpp
+++ b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter3/toy.cpp
@@ -863,7 +863,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -875,7 +875,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter4/toy.cpp b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter4/toy.cpp
--- a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter4/toy.cpp
+++ b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter4/toy.cpp
@@ -846,7 +846,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -858,7 +858,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/Chapter5/toy.cpp b/llvm/examples/Kaleidoscope/Chapter5/toy.cpp
--- a/llvm/examples/Kaleidoscope/Chapter5/toy.cpp
+++ b/llvm/examples/Kaleidoscope/Chapter5/toy.cpp
@@ -650,7 +650,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -662,7 +662,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/Chapter6/toy.cpp b/llvm/examples/Kaleidoscope/Chapter6/toy.cpp
--- a/llvm/examples/Kaleidoscope/Chapter6/toy.cpp
+++ b/llvm/examples/Kaleidoscope/Chapter6/toy.cpp
@@ -762,7 +762,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -774,7 +774,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/Chapter7/toy.cpp b/llvm/examples/Kaleidoscope/Chapter7/toy.cpp
--- a/llvm/examples/Kaleidoscope/Chapter7/toy.cpp
+++ b/llvm/examples/Kaleidoscope/Chapter7/toy.cpp
@@ -869,7 +869,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -881,7 +881,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/Chapter8/toy.cpp b/llvm/examples/Kaleidoscope/Chapter8/toy.cpp
--- a/llvm/examples/Kaleidoscope/Chapter8/toy.cpp
+++ b/llvm/examples/Kaleidoscope/Chapter8/toy.cpp
@@ -867,7 +867,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -879,7 +879,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/examples/Kaleidoscope/Chapter9/toy.cpp b/llvm/examples/Kaleidoscope/Chapter9/toy.cpp
--- a/llvm/examples/Kaleidoscope/Chapter9/toy.cpp
+++ b/llvm/examples/Kaleidoscope/Chapter9/toy.cpp
@@ -1037,7 +1037,7 @@
   ThenBB = Builder->GetInsertBlock();
 
   // Emit else block.
-  TheFunction->getBasicBlockList().push_back(ElseBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), ElseBB);
   Builder->SetInsertPoint(ElseBB);
 
   Value *ElseV = Else->codegen();
@@ -1049,7 +1049,7 @@
   ElseBB = Builder->GetInsertBlock();
 
   // Emit merge block.
-  TheFunction->getBasicBlockList().push_back(MergeBB);
+  TheFunction->insertBasicBlockAt(TheFunction->end(), MergeBB);
   Builder->SetInsertPoint(MergeBB);
   PHINode *PN = Builder->CreatePHI(Type::getDoubleTy(*TheContext), 2, "iftmp");
 
diff --git a/llvm/include/llvm/IR/Function.h b/llvm/include/llvm/IR/Function.h
--- a/llvm/include/llvm/IR/Function.h
+++ b/llvm/include/llvm/IR/Function.h
@@ -678,6 +678,12 @@
   /// Requires that this has no function body.
   void stealArgumentListFrom(Function &Src);
 
+  /// Insert \p BB in the basic block list at \p Position. \Returns an iterator
+  /// to the newly inserted BB.
+  Function::iterator insertBasicBlockAt(Function::iterator Position, BasicBlock *BB) {
+    return BasicBlocks.insert(Position, BB);
+  }
+
   /// Get the underlying elements of the Function... the basic block list is
   /// empty for external functions.
   ///
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
--- a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
+++ b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -3617,7 +3617,7 @@
   // Emit thenBB and set the Builder's insertion point there for
   // body generation next. Place the block after the current block.
   Function *CurFn = EntryBB->getParent();
-  CurFn->getBasicBlockList().insertAfter(EntryBB->getIterator(), ThenBB);
+  CurFn->insertBasicBlockAt(std::next(EntryBB->getIterator()), ThenBB);
 
   // Move Entry branch to end of ThenBB, and replace with conditional
   // branch (If-stmt)
diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -62,9 +62,9 @@
   assert(!Parent && "Already has a parent");
 
   if (InsertBefore)
-    NewParent->getBasicBlockList().insert(InsertBefore->getIterator(), this);
+    NewParent->insertBasicBlockAt(InsertBefore->getIterator(), this);
   else
-    NewParent->getBasicBlockList().push_back(this);
+    NewParent->insertBasicBlockAt(NewParent->end(), this);
 }
 
 BasicBlock::~BasicBlock() {
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -2655,13 +2655,14 @@
   BasicBlock *ToInsert = unwrap(BB);
   BasicBlock *CurBB = unwrap(Builder)->GetInsertBlock();
   assert(CurBB && "current insertion point is invalid!");
-  CurBB->getParent()->getBasicBlockList().insertAfter(CurBB->getIterator(),
-                                                      ToInsert);
+  CurBB->getParent()->insertBasicBlockAt(std::next(CurBB->getIterator()),
+                                         ToInsert);
 }
 
 void LLVMAppendExistingBasicBlock(LLVMValueRef Fn,
                                   LLVMBasicBlockRef BB) {
-  unwrap<Function>(Fn)->getBasicBlockList().push_back(unwrap(BB));
+  unwrap<Function>(Fn)->insertBasicBlockAt(unwrap<Function>(Fn)->end(),
+                                           unwrap(BB));
 }
 
 LLVMBasicBlockRef LLVMAppendBasicBlockInContext(LLVMContextRef C,
diff --git a/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp b/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp
--- a/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp
+++ b/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp
@@ -179,7 +179,7 @@
   // Insert the block into the function... right after the block TI lives in.
   Function &F = *TIBB->getParent();
   Function::iterator FBBI = TIBB->getIterator();
-  F.getBasicBlockList().insert(++FBBI, NewBB);
+  F.insertBasicBlockAt(++FBBI, NewBB);
 
   // Branch to the new block, breaking the edge.
   TI->setSuccessor(SuccNum, NewBB);
diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -670,7 +670,7 @@
       continue; // Dead block.
 
     // Add the new block to the new function.
-    NewFunc->getBasicBlockList().push_back(NewBB);
+    NewFunc->insertBasicBlockAt(NewFunc->end(), NewBB);
 
     // Handle PHI nodes specially, as we have to remove references to dead
     // blocks.
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -999,7 +999,7 @@
 
     newFunction->addFnAttr(Attr);
   }
-  newFunction->getBasicBlockList().push_back(newRootNode);
+  newFunction->insertBasicBlockAt(newFunction->end(), newRootNode);
 
   // Create scalar and aggregate iterators to name all of the arguments we
   // inserted.
@@ -1435,21 +1435,17 @@
 }
 
 void CodeExtractor::moveCodeToFunction(Function *newFunction) {
-  Function *oldFunc = (*Blocks.begin())->getParent();
-  Function::BasicBlockListType &oldBlocks = oldFunc->getBasicBlockList();
-  Function::BasicBlockListType &newBlocks = newFunction->getBasicBlockList();
-
   auto newFuncIt = newFunction->front().getIterator();
   for (BasicBlock *Block : Blocks) {
     // Delete the basic block from the old function, and the list of blocks
-    oldBlocks.remove(Block);
+    Block->removeFromParent();
 
     // Insert this basic block into the new function
     // Insert the original blocks after the entry block created
     // for the new function. The entry block may be followed
     // by a set of exit blocks at this point, but these exit
     // blocks better be placed at the end of the new function.
-    newFuncIt = newBlocks.insertAfter(newFuncIt, Block);
+    newFuncIt = newFunction->insertBasicBlockAt(std::next(newFuncIt), Block);
   }
 }
 
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
--- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -540,7 +540,7 @@
     for (LoopBlocksDFS::RPOIterator BB = BlockBegin; BB != BlockEnd; ++BB) {
       ValueToValueMapTy VMap;
       BasicBlock *New = CloneBasicBlock(*BB, VMap, "." + Twine(It));
-      Header->getParent()->getBasicBlockList().insert(BlockInsertPt, New);
+      Header->getParent()->insertBasicBlockAt(BlockInsertPt, New);
 
       assert((*BB != Header || LI->getLoopFor(*BB) == L) &&
              "Header should not be in a sub-loop");
diff --git a/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp b/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
--- a/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
@@ -374,7 +374,7 @@
     for (LoopBlocksDFS::RPOIterator BB = BlockBegin; BB != BlockEnd; ++BB) {
       ValueToValueMapTy VMap;
       BasicBlock *New = CloneBasicBlock(*BB, VMap, "." + Twine(It));
-      Header->getParent()->getBasicBlockList().push_back(New);
+      Header->getParent()->insertBasicBlockAt(Header->getParent()->end(), New);
 
       // Tell LI about New.
       addClonedBlockToLoopInfo(*BB, New, LI, NewLoops);
diff --git a/llvm/lib/Transforms/Utils/LowerSwitch.cpp b/llvm/lib/Transforms/Utils/LowerSwitch.cpp
--- a/llvm/lib/Transforms/Utils/LowerSwitch.cpp
+++ b/llvm/lib/Transforms/Utils/LowerSwitch.cpp
@@ -160,7 +160,7 @@
                          BasicBlock *Default) {
   Function *F = OrigBlock->getParent();
   BasicBlock *NewLeaf = BasicBlock::Create(Val->getContext(), "LeafBlock");
-  F->getBasicBlockList().insert(++OrigBlock->getIterator(), NewLeaf);
+  F->insertBasicBlockAt(++OrigBlock->getIterator(), NewLeaf);
 
   // Emit comparison
   ICmpInst *Comp = nullptr;
@@ -300,7 +300,7 @@
       SwitchConvert(RHS.begin(), RHS.end(), NewLowerBound, UpperBound, Val,
                     NewNode, OrigBlock, Default, UnreachableRanges);
 
-  F->getBasicBlockList().insert(++OrigBlock->getIterator(), NewNode);
+  F->insertBasicBlockAt(++OrigBlock->getIterator(), NewNode);
   Comp->insertAt(NewNode, NewNode->end());
 
   BranchInst::Create(LBranch, RBranch, Comp, NewNode);
diff --git a/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp b/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp
--- a/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp
+++ b/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp
@@ -325,8 +325,7 @@
   EXPECT_TRUE(IR.isSuccess());
   invalidate(*F1);
   FPU.finish(FAM);
-  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount),
-            F1->getBasicBlockList().size());
+  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount), F1->size());
   EXPECT_EQ(static_cast<size_t>(FPI.TotalInstructionCount),
             F1->getInstructionCount());
 }
@@ -379,8 +378,7 @@
   EXPECT_TRUE(IR.isSuccess());
   invalidate(*F1);
   FPU.finish(FAM);
-  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount),
-            F1->getBasicBlockList().size() - 1);
+  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount), F1->size() - 1);
   EXPECT_EQ(static_cast<size_t>(FPI.TotalInstructionCount),
             F1->getInstructionCount() - 2);
   EXPECT_EQ(FPI, FunctionPropertiesInfo::getFunctionPropertiesInfo(*F1, FAM));
@@ -434,8 +432,7 @@
   EXPECT_TRUE(IR.isSuccess());
   invalidate(*F1);
   FPU.finish(FAM);
-  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount),
-            F1->getBasicBlockList().size() - 1);
+  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount), F1->size() - 1);
   EXPECT_EQ(static_cast<size_t>(FPI.TotalInstructionCount),
             F1->getInstructionCount() - 2);
   EXPECT_EQ(FPI, FunctionPropertiesInfo::getFunctionPropertiesInfo(*F1, FAM));
@@ -487,8 +484,7 @@
   EXPECT_TRUE(IR.isSuccess());
   invalidate(*F1);
   FPU.finish(FAM);
-  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount),
-            F1->getBasicBlockList().size() - 1);
+  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount), F1->size() - 1);
   EXPECT_EQ(static_cast<size_t>(FPI.TotalInstructionCount),
             F1->getInstructionCount() - 2);
   EXPECT_EQ(FPI, FunctionPropertiesInfo::getFunctionPropertiesInfo(*F1, FAM));
@@ -544,8 +540,7 @@
   EXPECT_TRUE(IR.isSuccess());
   invalidate(*F1);
   FPU.finish(FAM);
-  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount),
-            F1->getBasicBlockList().size() - 1);
+  EXPECT_EQ(static_cast<size_t>(FPI.BasicBlockCount), F1->size() - 1);
   EXPECT_EQ(static_cast<size_t>(FPI.TotalInstructionCount),
             F1->getInstructionCount() - 2);
   EXPECT_EQ(FPI, FunctionPropertiesInfo::getFunctionPropertiesInfo(*F1, FAM));
diff --git a/llvm/unittests/IR/FunctionTest.cpp b/llvm/unittests/IR/FunctionTest.cpp
--- a/llvm/unittests/IR/FunctionTest.cpp
+++ b/llvm/unittests/IR/FunctionTest.cpp
@@ -7,12 +7,29 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/IR/Function.h"
+#include "llvm/AsmParser/Parser.h"
 #include "llvm/IR/Module.h"
+#include "llvm/Support/SourceMgr.h"
 #include "gtest/gtest.h"
 using namespace llvm;
 
 namespace {
 
+static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
+  SMDiagnostic Err;
+  std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
+  if (!Mod)
+    Err.print("InstructionsTests", errs());
+  return Mod;
+}
+
+static BasicBlock *getBBWithName(Function *F, StringRef Name) {
+  auto It = find_if(
+      *F, [&Name](const BasicBlock &BB) { return BB.getName() == Name; });
+  assert(It != F->end() && "Not found!");
+  return &*It;
+}
+
 TEST(FunctionTest, hasLazyArguments) {
   LLVMContext C;
 
@@ -162,4 +179,64 @@
   EXPECT_EQ(Align(4), Func->getPointerAlignment(DataLayout("Fn32")));
 }
 
+TEST(FunctionTest, InsertBasicBlockAt) {
+  LLVMContext C;
+  std::unique_ptr<Module> M = parseIR(C, R"(
+define void @foo(i32 %a, i32 %b) {
+foo_bb0:
+  ret void
+}
+
+define void @bar() {
+bar_bb0:
+  br label %bar_bb1
+bar_bb1:
+  br label %bar_bb2
+bar_bb2:
+  ret void
+}
+)");
+  Function *FooF = M->getFunction("foo");
+  BasicBlock *FooBB0 = getBBWithName(FooF, "foo_bb0");
+
+  Function *BarF = M->getFunction("bar");
+  BasicBlock *BarBB0 = getBBWithName(BarF, "bar_bb0");
+  BasicBlock *BarBB1 = getBBWithName(BarF, "bar_bb1");
+  BasicBlock *BarBB2 = getBBWithName(BarF, "bar_bb2");
+
+  // Insert foo_bb0 into bar() at the very top.
+  FooBB0->removeFromParent();
+  auto It = BarF->insertBasicBlockAt(BarF->begin(), FooBB0);
+  EXPECT_EQ(BarBB0->getPrevNode(), FooBB0);
+  EXPECT_EQ(It, FooBB0->getIterator());
+
+  // Insert foo_bb0 into bar() at the very end.
+  FooBB0->removeFromParent();
+  It = BarF->insertBasicBlockAt(BarF->end(), FooBB0);
+  EXPECT_EQ(FooBB0->getPrevNode(), BarBB2);
+  EXPECT_EQ(FooBB0->getNextNode(), nullptr);
+  EXPECT_EQ(It, FooBB0->getIterator());
+
+  // Insert foo_bb0 into bar() just before bar_bb0.
+  FooBB0->removeFromParent();
+  It = BarF->insertBasicBlockAt(BarBB0->getIterator(), FooBB0);
+  EXPECT_EQ(FooBB0->getPrevNode(), nullptr);
+  EXPECT_EQ(FooBB0->getNextNode(), BarBB0);
+  EXPECT_EQ(It, FooBB0->getIterator());
+
+  // Insert foo_bb0 into bar() just before bar_bb1.
+  FooBB0->removeFromParent();
+  It = BarF->insertBasicBlockAt(BarBB1->getIterator(), FooBB0);
+  EXPECT_EQ(FooBB0->getPrevNode(), BarBB0);
+  EXPECT_EQ(FooBB0->getNextNode(), BarBB1);
+  EXPECT_EQ(It, FooBB0->getIterator());
+
+  // Insert foo_bb0 into bar() just before bar_bb2.
+  FooBB0->removeFromParent();
+  It = BarF->insertBasicBlockAt(BarBB2->getIterator(), FooBB0);
+  EXPECT_EQ(FooBB0->getPrevNode(), BarBB1);
+  EXPECT_EQ(FooBB0->getNextNode(), BarBB2);
+  EXPECT_EQ(It, FooBB0->getIterator());
+}
+
 } // end namespace