diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
@@ -181,6 +181,8 @@
 
   int getMemcpyCost(const Instruction *I);
 
+  int getNumMemOps(const IntrinsicInst *I) const;
+
   int getShuffleCost(TTI::ShuffleKind Kind, VectorType *Tp, int Index,
                      VectorType *SubTp);
 
diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
@@ -951,39 +951,85 @@
           (EltWidth == 16 && Alignment >= 2) || EltWidth == 8);
 }
 
-int ARMTTIImpl::getMemcpyCost(const Instruction *I) {
-  const MemCpyInst *MI = dyn_cast<MemCpyInst>(I);
-  assert(MI && "MemcpyInst expected");
-  ConstantInt *C = dyn_cast<ConstantInt>(MI->getLength());
-
-  // To model the cost of a library call, we assume 1 for the call, and
-  // 3 for the argument setup.
-  const unsigned LibCallCost = 4;
+/// Given a memcpy/memset/memmove instruction, return the number of memory
+/// operations performed, via querying findOptimalMemOpLowering. Returns -1 if a
+/// call is used.
+int ARMTTIImpl::getNumMemOps(const IntrinsicInst *I) const {
+  MemOp MOp;
+  unsigned DstAddrSpace = ~0u;
+  unsigned SrcAddrSpace = ~0u;
+  const Function *F = I->getParent()->getParent();
 
-  // If 'size' is not a constant, a library call will be generated.
-  if (!C)
-    return LibCallCost;
+  if (const auto *MC = dyn_cast<MemTransferInst>(I)) {
+    ConstantInt *C = dyn_cast<ConstantInt>(MC->getLength());
+    // If 'size' is not a constant, a library call will be generated.
+    if (!C)
+      return -1;
+
+    const unsigned Size = C->getValue().getZExtValue();
+    const Align DstAlign = *MC->getDestAlign();
+    const Align SrcAlign = *MC->getSourceAlign();
+    const Function *F = I->getParent()->getParent();
+    std::vector<EVT> MemOps;
+
+    MOp = MemOp::Copy(Size, /*DstAlignCanChange*/ false, DstAlign, SrcAlign,
+                      /*IsVolatile*/ false);
+    DstAddrSpace = MC->getDestAddressSpace();
+    SrcAddrSpace = MC->getSourceAddressSpace();
+  }
+  else if (const auto *MS = dyn_cast<MemSetInst>(I)) {
+    ConstantInt *C = dyn_cast<ConstantInt>(MS->getLength());
+    // If 'size' is not a constant, a library call will be generated.
+    if (!C)
+      return -1;
+
+    const unsigned Size = C->getValue().getZExtValue();
+    const Align DstAlign = *MS->getDestAlign();
+
+    MOp = MemOp::Set(Size, /*DstAlignCanChange*/ false, DstAlign,
+                     /*IsZeroMemset*/ false, /*IsVolatile*/ false);
+    DstAddrSpace = MS->getDestAddressSpace();
+  }
+  else
+    llvm_unreachable("Expected a memcpy/move or memset!");
 
-  const unsigned Size = C->getValue().getZExtValue();
-  const Align DstAlign = *MI->getDestAlign();
-  const Align SrcAlign = *MI->getSourceAlign();
-  const Function *F = I->getParent()->getParent();
-  const unsigned Limit = TLI->getMaxStoresPerMemmove(F->hasMinSize());
-  std::vector<EVT> MemOps;
+  unsigned Limit, Factor = 2;
+  switch(I->getIntrinsicID()) {
+    case Intrinsic::memcpy:
+      Limit = TLI->getMaxStoresPerMemcpy(F->hasMinSize());
+      break;
+    case Intrinsic::memmove:
+      Limit = TLI->getMaxStoresPerMemmove(F->hasMinSize());
+      break;
+    case Intrinsic::memset:
+      Limit = TLI->getMaxStoresPerMemset(F->hasMinSize());
+      Factor = 1;
+      break;
+    default:
+      llvm_unreachable("Expected a memcpy/move or memset!");
+  }
 
   // MemOps will be poplulated with a list of data types that needs to be
   // loaded and stored. That's why we multiply the number of elements by 2 to
   // get the cost for this memcpy.
+  std::vector<EVT> MemOps;
   if (getTLI()->findOptimalMemOpLowering(
-          MemOps, Limit,
-          MemOp::Copy(Size, /*DstAlignCanChange*/ false, DstAlign, SrcAlign,
-                      /*IsVolatile*/ true),
-          MI->getDestAddressSpace(), MI->getSourceAddressSpace(),
-          F->getAttributes()))
-    return MemOps.size() * 2;
+          MemOps, Limit, MOp, DstAddrSpace,
+          SrcAddrSpace, F->getAttributes()))
+    return MemOps.size() * Factor;
 
   // If we can't find an optimal memop lowering, return the default cost
-  return LibCallCost;
+  return -1;
+}
+
+int ARMTTIImpl::getMemcpyCost(const Instruction *I) {
+  int NumOps = getNumMemOps(cast<IntrinsicInst>(I));
+
+  // To model the cost of a library call, we assume 1 for the call, and
+  // 3 for the argument setup.
+  if (NumOps == -1)
+    return 4;
+  return NumOps;
 }
 
 int ARMTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, VectorType *Tp,
@@ -1520,9 +1566,16 @@
   // Check if an intrinsic will be lowered to a call and assume that any
   // other CallInst will generate a bl.
   if (auto *Call = dyn_cast<CallInst>(&I)) {
-    if (isa<IntrinsicInst>(Call)) {
-      if (const Function *F = Call->getCalledFunction())
-        return isLoweredToCall(F);
+    if (auto *II = dyn_cast<IntrinsicInst>(Call)) {
+      switch(II->getIntrinsicID()) {
+        case Intrinsic::memcpy:
+        case Intrinsic::memset:
+        case Intrinsic::memmove:
+          return getNumMemOps(II) == -1;
+        default:
+          if (const Function *F = Call->getCalledFunction())
+            return isLoweredToCall(F);
+      }
     }
     return true;
   }
diff --git a/llvm/test/CodeGen/Thumb2/LowOverheadLoops/memcall.ll b/llvm/test/CodeGen/Thumb2/LowOverheadLoops/memcall.ll
--- a/llvm/test/CodeGen/Thumb2/LowOverheadLoops/memcall.ll
+++ b/llvm/test/CodeGen/Thumb2/LowOverheadLoops/memcall.ll
@@ -12,23 +12,20 @@
 ; CHECK-NEXT:    blt .LBB0_3
 ; CHECK-NEXT:  @ %bb.1: @ %for.body.preheader
 ; CHECK-NEXT:    mov r8, r3
-; CHECK-NEXT:    mov lr, r2
+; CHECK-NEXT:    mov r5, r2
 ; CHECK-NEXT:    mov r9, r1
-; CHECK-NEXT:    mov r6, r0
-; CHECK-NEXT:    lsls r7, r3, #2
-; CHECK-NEXT:    movs r4, #0
+; CHECK-NEXT:    mov r7, r0
+; CHECK-NEXT:    lsls r4, r3, #2
+; CHECK-NEXT:    movs r6, #0
 ; CHECK-NEXT:  .LBB0_2: @ %for.body
 ; CHECK-NEXT:    @ =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    adds r0, r6, r4
-; CHECK-NEXT:    add.w r1, r9, r4
+; CHECK-NEXT:    adds r0, r7, r6
+; CHECK-NEXT:    add.w r1, r9, r6
 ; CHECK-NEXT:    mov r2, r8
-; CHECK-NEXT:    mov r5, lr
 ; CHECK-NEXT:    bl __aeabi_memcpy4
-; CHECK-NEXT:    mov lr, r5
-; CHECK-NEXT:    add r4, r7
-; CHECK-NEXT:    subs.w lr, lr, #1
+; CHECK-NEXT:    add r6, r4
+; CHECK-NEXT:    subs r5, #1
 ; CHECK-NEXT:    bne .LBB0_2
-; CHECK-NEXT:    b .LBB0_3
 ; CHECK-NEXT:  .LBB0_3: @ %for.cond.cleanup
 ; CHECK-NEXT:    add sp, #4
 ; CHECK-NEXT:    pop.w {r4, r5, r6, r7, r8, r9, pc}
@@ -64,20 +61,17 @@
 ; CHECK-NEXT:    blt .LBB1_3
 ; CHECK-NEXT:  @ %bb.1: @ %for.body.preheader
 ; CHECK-NEXT:    mov r4, r2
-; CHECK-NEXT:    mov lr, r1
-; CHECK-NEXT:    mov r5, r0
-; CHECK-NEXT:    lsls r6, r2, #2
+; CHECK-NEXT:    mov r5, r1
+; CHECK-NEXT:    mov r6, r0
+; CHECK-NEXT:    lsls r7, r2, #2
 ; CHECK-NEXT:  .LBB1_2: @ %for.body
 ; CHECK-NEXT:    @ =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    mov r0, r5
+; CHECK-NEXT:    mov r0, r6
 ; CHECK-NEXT:    mov r1, r4
-; CHECK-NEXT:    mov r7, lr
 ; CHECK-NEXT:    bl __aeabi_memclr4
-; CHECK-NEXT:    mov lr, r7
-; CHECK-NEXT:    add r5, r6
-; CHECK-NEXT:    subs.w lr, lr, #1
+; CHECK-NEXT:    add r6, r7
+; CHECK-NEXT:    subs r5, #1
 ; CHECK-NEXT:    bne .LBB1_2
-; CHECK-NEXT:    b .LBB1_3
 ; CHECK-NEXT:  .LBB1_3: @ %for.cond.cleanup
 ; CHECK-NEXT:    add sp, #4
 ; CHECK-NEXT:    pop {r4, r5, r6, r7, pc}
@@ -110,23 +104,20 @@
 ; CHECK-NEXT:    blt .LBB2_3
 ; CHECK-NEXT:  @ %bb.1: @ %for.body.preheader
 ; CHECK-NEXT:    mov r8, r3
-; CHECK-NEXT:    mov lr, r2
+; CHECK-NEXT:    mov r5, r2
 ; CHECK-NEXT:    mov r9, r1
-; CHECK-NEXT:    mov r6, r0
-; CHECK-NEXT:    lsls r7, r3, #2
-; CHECK-NEXT:    movs r4, #0
+; CHECK-NEXT:    mov r7, r0
+; CHECK-NEXT:    lsls r4, r3, #2
+; CHECK-NEXT:    movs r6, #0
 ; CHECK-NEXT:  .LBB2_2: @ %for.body
 ; CHECK-NEXT:    @ =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    adds r0, r6, r4
-; CHECK-NEXT:    add.w r1, r9, r4
+; CHECK-NEXT:    adds r0, r7, r6
+; CHECK-NEXT:    add.w r1, r9, r6
 ; CHECK-NEXT:    mov r2, r8
-; CHECK-NEXT:    mov r5, lr
 ; CHECK-NEXT:    bl __aeabi_memmove4
-; CHECK-NEXT:    mov lr, r5
-; CHECK-NEXT:    add r4, r7
-; CHECK-NEXT:    subs.w lr, lr, #1
+; CHECK-NEXT:    add r6, r4
+; CHECK-NEXT:    subs r5, #1
 ; CHECK-NEXT:    bne .LBB2_2
-; CHECK-NEXT:    b .LBB2_3
 ; CHECK-NEXT:  .LBB2_3: @ %for.cond.cleanup
 ; CHECK-NEXT:    add sp, #4
 ; CHECK-NEXT:    pop.w {r4, r5, r6, r7, r8, r9, pc}