diff --git a/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h b/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
--- a/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
+++ b/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
@@ -1408,13 +1408,10 @@
   friend class OpenMPIRBuilder;
 
 private:
-  BasicBlock *Preheader = nullptr;
   BasicBlock *Header = nullptr;
   BasicBlock *Cond = nullptr;
-  BasicBlock *Body = nullptr;
   BasicBlock *Latch = nullptr;
   BasicBlock *Exit = nullptr;
-  BasicBlock *After = nullptr;
 
   /// Add the control blocks of this loop to \p BBs.
   ///
@@ -1436,10 +1433,7 @@
   /// Code that must be execute before any loop iteration can be emitted here,
   /// such as computing the loop trip count and begin lifetime markers. Code in
   /// the preheader is not considered part of the canonical loop.
-  BasicBlock *getPreheader() const {
-    assert(isValid() && "Requires a valid canonical loop");
-    return Preheader;
-  }
+  BasicBlock *getPreheader() const;
 
   /// The header is the entry for each iteration. In the canonical control flow,
   /// it only contains the PHINode for the induction variable.
@@ -1460,7 +1454,7 @@
   /// eventually branch to the \p Latch block.
   BasicBlock *getBody() const {
     assert(isValid() && "Requires a valid canonical loop");
-    return Body;
+    return cast<BranchInst>(Cond->getTerminator())->getSuccessor(0);
   }
 
   /// Reaching the latch indicates the end of the loop body code. In the
@@ -1484,7 +1478,7 @@
   /// statements/cancellations).
   BasicBlock *getAfter() const {
     assert(isValid() && "Requires a valid canonical loop");
-    return After;
+    return Exit->getSingleSuccessor();
   }
 
   /// Returns the llvm::Value containing the number of loop iterations. It must
@@ -1515,18 +1509,21 @@
   /// Return the insertion point for user code before the loop.
   OpenMPIRBuilder::InsertPointTy getPreheaderIP() const {
     assert(isValid() && "Requires a valid canonical loop");
+    BasicBlock *Preheader = getPreheader();
     return {Preheader, std::prev(Preheader->end())};
   };
 
   /// Return the insertion point for user code in the body.
   OpenMPIRBuilder::InsertPointTy getBodyIP() const {
     assert(isValid() && "Requires a valid canonical loop");
+    BasicBlock *Body = getBody();
     return {Body, Body->begin()};
   };
 
   /// Return the insertion point for user code after the loop.
   OpenMPIRBuilder::InsertPointTy getAfterIP() const {
     assert(isValid() && "Requires a valid canonical loop");
+    BasicBlock *After = getAfter();
     return {After, After->begin()};
   };
 
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
@@ -1327,13 +1327,10 @@
   LoopInfos.emplace_front();
   CanonicalLoopInfo *CL = &LoopInfos.front();
 
-  CL->Preheader = Preheader;
   CL->Header = Header;
   CL->Cond = Cond;
-  CL->Body = Body;
   CL->Latch = Latch;
   CL->Exit = Exit;
-  CL->After = After;
 
 #ifndef NDEBUG
   CL->assertOK();
@@ -1357,7 +1354,7 @@
     // Split the loop at the insertion point: Branch to the preheader and move
     // every following instruction to after the loop (the After BB). Also, the
     // new successor is the loop's after block.
-    Builder.CreateBr(CL->Preheader);
+    Builder.CreateBr(CL->getPreheader());
     After->getInstList().splice(After->begin(), BB->getInstList(),
                                 Builder.GetInsertPoint(), BB->end());
     After->replaceSuccessorsPhiUsesWith(BB, After);
@@ -1789,6 +1786,12 @@
   BasicBlock *OrigAfter = Outermost->getAfter();
   Function *F = OrigPreheader->getParent();
 
+  // Loop control blocks that may become orphaned later.
+  SmallVector<BasicBlock *, 12> OldControlBBs;
+  OldControlBBs.reserve(6 * Loops.size());
+  for (CanonicalLoopInfo *Loop : Loops)
+    Loop->collectControlBlocks(OldControlBBs);
+
   // Setup the IRBuilder for inserting the trip count computation.
   Builder.SetCurrentDebugLocation(DL);
   if (ComputeIP.isSet())
@@ -1884,10 +1887,6 @@
     Loops[i]->getIndVar()->replaceAllUsesWith(NewIndVars[i]);
 
   // Remove unused parts of the input loops.
-  SmallVector<BasicBlock *, 12> OldControlBBs;
-  OldControlBBs.reserve(6 * Loops.size());
-  for (CanonicalLoopInfo *Loop : Loops)
-    Loop->collectControlBlocks(OldControlBBs);
   removeUnusedBlocksFromParent(OldControlBBs);
 
   for (CanonicalLoopInfo *L : Loops)
@@ -1913,6 +1912,12 @@
   BasicBlock *InnerEnter = InnermostLoop->getBody();
   BasicBlock *InnerLatch = InnermostLoop->getLatch();
 
+  // Loop control blocks that may become orphaned later.
+  SmallVector<BasicBlock *, 12> OldControlBBs;
+  OldControlBBs.reserve(6 * Loops.size());
+  for (CanonicalLoopInfo *Loop : Loops)
+    Loop->collectControlBlocks(OldControlBBs);
+
   // Collect original trip counts and induction variable to be accessible by
   // index. Also, the structure of the original loops is not preserved during
   // the construction of the tiled loops, so do it before we scavenge the BBs of
@@ -2072,10 +2077,6 @@
   }
 
   // Remove unused parts of the original loops.
-  SmallVector<BasicBlock *, 12> OldControlBBs;
-  OldControlBBs.reserve(6 * Loops.size());
-  for (CanonicalLoopInfo *Loop : Loops)
-    Loop->collectControlBlocks(OldControlBBs);
   removeUnusedBlocksFromParent(OldControlBBs);
 
   for (CanonicalLoopInfo *L : Loops)
@@ -3319,7 +3320,16 @@
   // flow. For consistency, this also means we do not add the Body block, which
   // is just the entry to the body code.
   BBs.reserve(BBs.size() + 6);
-  BBs.append({Preheader, Header, Cond, Latch, Exit, After});
+  BBs.append({getPreheader(), Header, Cond, Latch, Exit, getAfter()});
+}
+
+BasicBlock *CanonicalLoopInfo::getPreheader() const {
+  assert(isValid() && "Requires a valid canonical loop");
+  for (BasicBlock *Pred : predecessors(Header)) {
+    if (Pred != Latch)
+      return Pred;
+  }
+  llvm_unreachable("Missing preheader");
 }
 
 void CanonicalLoopInfo::assertOK() const {
@@ -3328,6 +3338,10 @@
   if (!isValid())
     return;
 
+  BasicBlock *Preheader = getPreheader();
+  BasicBlock *Body = getBody();
+  BasicBlock *After = getAfter();
+
   // Verify standard control-flow we use for OpenMP loops.
   assert(Preheader);
   assert(isa<BranchInst>(Preheader->getTerminator()) &&
@@ -3413,11 +3427,8 @@
 }
 
 void CanonicalLoopInfo::invalidate() {
-  Preheader = nullptr;
   Header = nullptr;
   Cond = nullptr;
-  Body = nullptr;
   Latch = nullptr;
   Exit = nullptr;
-  After = nullptr;
 }