diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -3022,19 +3022,24 @@
       return;
     }
     case Instruction::Call: {
-      // Check if the calls are all to the same vectorizable intrinsic.
+      // Check if the calls are all to the same vectorizable intrinsic or
+      // library function.
       CallInst *CI = cast<CallInst>(VL0);
-      // Check if this is an Intrinsic call or something that can be
-      // represented by an intrinsic call
       Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI);
-      if (!isTriviallyVectorizable(ID)) {
+
+      auto Shape =
+          VFShape::get(*CI, {static_cast<unsigned int>(VL.size()), false},
+                       false /*HasGlobalPred*/);
+      Function *VecFunc = VFDatabase(*CI).getVectorizedFunction(Shape);
+
+      if (!VecFunc && !isTriviallyVectorizable(ID)) {
         BS.cancelScheduling(VL, VL0);
         newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
                      ReuseShuffleIndicies);
         LLVM_DEBUG(dbgs() << "SLP: Non-vectorizable call.\n");
         return;
       }
-      Function *Int = CI->getCalledFunction();
+      Function *F = CI->getCalledFunction();
       unsigned NumArgs = CI->getNumArgOperands();
       SmallVector<Value*, 4> ScalarArgs(NumArgs, nullptr);
       for (unsigned j = 0; j != NumArgs; ++j)
@@ -3042,8 +3047,10 @@
           ScalarArgs[j] = CI->getArgOperand(j);
       for (Value *V : VL) {
         CallInst *CI2 = dyn_cast<CallInst>(V);
-        if (!CI2 || CI2->getCalledFunction() != Int ||
+        if (!CI2 || CI2->getCalledFunction() != F ||
             getVectorIntrinsicIDForCall(CI2, TLI) != ID ||
+            (VecFunc &&
+             VecFunc != VFDatabase(*CI2).getVectorizedFunction(Shape)) ||
             !CI->hasIdenticalOperandBundleSchema(*CI2)) {
           BS.cancelScheduling(VL, VL0);
           newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
@@ -4507,7 +4514,8 @@
       Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI);
 
       auto VecCallCosts = getVectorCallCosts(CI, VecTy, TTI, TLI);
-      bool UseIntrinsic = VecCallCosts.first <= VecCallCosts.second;
+      bool UseIntrinsic = ID != Intrinsic::not_intrinsic &&
+                          VecCallCosts.first <= VecCallCosts.second;
 
       Value *ScalarArg = nullptr;
       std::vector<Value *> OpVecs;
@@ -4527,15 +4535,16 @@
         OpVecs.push_back(OpVec);
       }
 
-      Module *M = F->getParent();
-      Type *Tys[] = {FixedVectorType::get(CI->getType(), E->Scalars.size())};
-      Function *CF = Intrinsic::getDeclaration(M, ID, Tys);
-
+      Function *CF;
       if (!UseIntrinsic) {
         VFShape Shape = VFShape::get(
             *CI, {static_cast<unsigned>(VecTy->getNumElements()), false},
             false /*HasGlobalPred*/);
         CF = VFDatabase(*CI).getVectorizedFunction(Shape);
+      } else {
+        Module *M = F->getParent();
+        Type *Tys[] = {FixedVectorType::get(CI->getType(), E->Scalars.size())};
+        CF = Intrinsic::getDeclaration(M, ID, Tys);
       }
 
       SmallVector<OperandBundleDef, 1> OpBundles;
@@ -5086,6 +5095,12 @@
   return II && II->getIntrinsicID() == Intrinsic::sideeffect;
 }
 
+static bool isVectorizableLibFunctionCall(Instruction *I) {
+  auto *CI = dyn_cast<CallInst>(I);
+
+  return CI && !VFDatabase::getMappings(*CI).empty();
+}
+
 void BoUpSLP::BlockScheduling::initScheduleData(Instruction *FromI,
                                                 Instruction *ToI,
                                                 ScheduleData *PrevLoadStore,
@@ -5102,7 +5117,8 @@
            "new ScheduleData already in scheduling region");
     SD->init(SchedulingRegionID, I);
 
-    if (I->mayReadOrWriteMemory() && !isSideeffectIntrinsic(I)) {
+    if (I->mayReadOrWriteMemory() && !isSideeffectIntrinsic(I) &&
+        !isVectorizableLibFunctionCall(I)) {
       // Update the linked list of memory accessing instructions.
       if (CurrentLoadStore) {
         CurrentLoadStore->NextLoadStore = SD;