diff --git a/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp b/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
index 6601e70e495e6..9dc1764b49e46 100644
--- a/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
+++ b/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
@@ -394,11 +394,12 @@ bool PreISelIntrinsicLowering::expandMemIntrinsicUses(Function &F) const {
       Module *M = Memset->getModule();
       const DataLayout &DL = Memset->getDataLayout();
 
+      Type *DestPtrTy = Memset->getRawDest()->getType();
+      Type *SizeTTy = TLI.getSizeTType(*M);
       StringRef FuncName = "memset_pattern16";
-      FunctionCallee MSP = getOrInsertLibFunc(
-          M, TLI, LibFunc_memset_pattern16, Builder.getVoidTy(),
-          Memset->getRawDest()->getType(), Builder.getPtrTy(),
-          Memset->getLength()->getType());
+      FunctionCallee MSP = getOrInsertLibFunc(M, TLI, LibFunc_memset_pattern16,
+                                              Builder.getVoidTy(), DestPtrTy,
+                                              Builder.getPtrTy(), SizeTTy);
       inferNonMandatoryLibFuncAttrs(M, FuncName, TLI);
 
       // Otherwise we should form a memset_pattern16.  PatternValue is known
@@ -415,8 +416,9 @@ bool PreISelIntrinsicLowering::expandMemIntrinsicUses(Function &F) const {
       GV->setAlignment(Align(16));
       Value *PatternPtr = GV;
       Value *NumBytes = Builder.CreateMul(
-          Builder.getInt64(DL.getTypeAllocSize(Memset->getValue()->getType())),
-          Memset->getLength());
+          TLI.getAsSizeT(DL.getTypeAllocSize(Memset->getValue()->getType()),
+                         *M),
+          Builder.CreateZExtOrTrunc(Memset->getLength(), SizeTTy));
       CallInst *MemsetPattern16Call =
           Builder.CreateCall(MSP, {Memset->getRawDest(), PatternPtr, NumBytes});
       MemsetPattern16Call->setAAMetadata(Memset->getAAMetadata());
diff --git a/llvm/test/Transforms/PreISelIntrinsicLowering/X86/memset-pattern.ll b/llvm/test/Transforms/PreISelIntrinsicLowering/X86/memset-pattern.ll
index 7cfdcb8578809..c52213d9a951d 100644
--- a/llvm/test/Transforms/PreISelIntrinsicLowering/X86/memset-pattern.ll
+++ b/llvm/test/Transforms/PreISelIntrinsicLowering/X86/memset-pattern.ll
@@ -3,12 +3,14 @@
 
 ;.
 ; CHECK: @.memset_pattern = private unnamed_addr constant [2 x i64] [i64 -6148895925951734307, i64 -6148895925951734307], align 16
-; CHECK: @.memset_pattern.1 = private unnamed_addr constant [2 x i64] [i64 4614256656552045848, i64 4614256656552045848], align 16
-; CHECK: @.memset_pattern.2 = private unnamed_addr constant [8 x i16] [i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555], align 16
-; CHECK: @.memset_pattern.3 = private unnamed_addr constant i128 -113427455635030943652277463699152839203, align 16
-; CHECK: @.memset_pattern.4 = private unnamed_addr constant i128 -113427455635030943652277463699152839203, align 16
+; CHECK: @.memset_pattern.1 = private unnamed_addr constant [2 x i64] [i64 -6148895925951734307, i64 -6148895925951734307], align 16
+; CHECK: @.memset_pattern.2 = private unnamed_addr constant [2 x i64] [i64 -6148895925951734307, i64 -6148895925951734307], align 16
+; CHECK: @.memset_pattern.3 = private unnamed_addr constant [2 x i64] [i64 4614256656552045848, i64 4614256656552045848], align 16
+; CHECK: @.memset_pattern.4 = private unnamed_addr constant [8 x i16] [i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555, i16 -21555], align 16
 ; CHECK: @.memset_pattern.5 = private unnamed_addr constant i128 -113427455635030943652277463699152839203, align 16
 ; CHECK: @.memset_pattern.6 = private unnamed_addr constant i128 -113427455635030943652277463699152839203, align 16
+; CHECK: @.memset_pattern.7 = private unnamed_addr constant i128 -113427455635030943652277463699152839203, align 16
+; CHECK: @.memset_pattern.8 = private unnamed_addr constant i128 -113427455635030943652277463699152839203, align 16
 ;.
 define void @memset_pattern_i128_1_dynvalue(ptr %a, i128 %value) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i128_1_dynvalue(
@@ -31,7 +33,7 @@ define void @memset_pattern_i128_1_dynvalue(ptr %a, i128 %value) nounwind {
 define void @memset_pattern_i128_1(ptr %a, i128 %value) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i128_1(
 ; CHECK-SAME: ptr [[A:%.*]], i128 [[VALUE:%.*]]) #[[ATTR0]] {
-; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.3, i64 16)
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.5, i64 16)
 ; CHECK-NEXT:    ret void
 ;
   tail call void @llvm.experimental.memset.pattern(ptr %a, i128 u0xaaaaaaaabbbbbbbbccccccccdddddddd, i64 1, i1 false)
@@ -59,7 +61,7 @@ define void @memset_pattern_i128_1_nz_as(ptr addrspace(1) %a, i128 %value) nounw
 define void @memset_pattern_i128_1_align_attr(ptr align(16) %a, i128 %value) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i128_1_align_attr(
 ; CHECK-SAME: ptr align 16 [[A:%.*]], i128 [[VALUE:%.*]]) #[[ATTR0]] {
-; CHECK-NEXT:    call void @memset_pattern16(ptr align 16 [[A]], ptr @.memset_pattern.4, i64 16)
+; CHECK-NEXT:    call void @memset_pattern16(ptr align 16 [[A]], ptr @.memset_pattern.6, i64 16)
 ; CHECK-NEXT:    ret void
 ;
   tail call void @llvm.experimental.memset.pattern(ptr align(16) %a, i128 u0xaaaaaaaabbbbbbbbccccccccdddddddd, i64 1, i1 false)
@@ -69,7 +71,7 @@ define void @memset_pattern_i128_1_align_attr(ptr align(16) %a, i128 %value) nou
 define void @memset_pattern_i128_16(ptr %a) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i128_16(
 ; CHECK-SAME: ptr [[A:%.*]]) #[[ATTR0]] {
-; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.5, i64 256)
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.7, i64 256)
 ; CHECK-NEXT:    ret void
 ;
   tail call void @llvm.experimental.memset.pattern(ptr %a, i128 u0xaaaaaaaabbbbbbbbccccccccdddddddd, i64 16, i1 false)
@@ -80,7 +82,7 @@ define void @memset_pattern_i128_x(ptr %a, i64 %x) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i128_x(
 ; CHECK-SAME: ptr [[A:%.*]], i64 [[X:%.*]]) #[[ATTR0]] {
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul i64 16, [[X]]
-; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.6, i64 [[TMP1]])
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.8, i64 [[TMP1]])
 ; CHECK-NEXT:    ret void
 ;
   tail call void @llvm.experimental.memset.pattern(ptr %a, i128 u0xaaaaaaaabbbbbbbbccccccccdddddddd, i64 %x, i1 false)
@@ -110,7 +112,7 @@ define void @memset_pattern_i16_x(ptr %a, i64 %x) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i16_x(
 ; CHECK-SAME: ptr [[A:%.*]], i64 [[X:%.*]]) #[[ATTR0]] {
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul i64 2, [[X]]
-; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.2, i64 [[TMP1]])
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.4, i64 [[TMP1]])
 ; CHECK-NEXT:    ret void
 ;
   tail call void @llvm.experimental.memset.pattern(ptr %a, i16 u0xabcd, i64 %x, i1 false)
@@ -121,7 +123,7 @@ define void @memset_pattern_i64_x(ptr %a, i64 %x) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i64_x(
 ; CHECK-SAME: ptr [[A:%.*]], i64 [[X:%.*]]) #[[ATTR0]] {
 ; CHECK-NEXT:    [[TMP1:%.*]] = mul i64 8, [[X]]
-; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern, i64 [[TMP1]])
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.2, i64 [[TMP1]])
 ; CHECK-NEXT:    ret void
 ;
   tail call void @llvm.experimental.memset.pattern(ptr %a, i64 u0xaaaabbbbccccdddd, i64 %x, i1 false)
@@ -132,13 +134,37 @@ define void @memset_pattern_i64_x(ptr %a, i64 %x) nounwind {
 define void @memset_pattern_i64_128_tbaa(ptr %a) nounwind {
 ; CHECK-LABEL: define void @memset_pattern_i64_128_tbaa(
 ; CHECK-SAME: ptr [[A:%.*]]) #[[ATTR0]] {
-; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.1, i64 1024), !tbaa [[TBAA0:![0-9]+]]
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.3, i64 1024), !tbaa [[TBAA0:![0-9]+]]
 ; CHECK-NEXT:    ret void
 ;
   tail call void @llvm.experimental.memset.pattern(ptr %a, i64 u0x400921fb54442d18, i64 128, i1 false), !tbaa !5
   ret void
 }
 
+define void @memset_pattern_i64_narrow_idx(ptr %a, i32 %x) nounwind {
+; CHECK-LABEL: define void @memset_pattern_i64_narrow_idx(
+; CHECK-SAME: ptr [[A:%.*]], i32 [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i32 [[X]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = mul i64 8, [[TMP1]]
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern.1, i64 [[TMP2]])
+; CHECK-NEXT:    ret void
+;
+  tail call void @llvm.experimental.memset.pattern(ptr %a, i64 u0xaaaabbbbccccdddd, i32 %x, i1 false)
+  ret void
+}
+
+define void @memset_pattern_i64_wide_idx(ptr %a, i128 %x) nounwind {
+; CHECK-LABEL: define void @memset_pattern_i64_wide_idx(
+; CHECK-SAME: ptr [[A:%.*]], i128 [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc i128 [[X]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = mul i64 8, [[TMP1]]
+; CHECK-NEXT:    call void @memset_pattern16(ptr [[A]], ptr @.memset_pattern, i64 [[TMP2]])
+; CHECK-NEXT:    ret void
+;
+  tail call void @llvm.experimental.memset.pattern(ptr %a, i64 u0xaaaabbbbccccdddd, i128 %x, i1 false)
+  ret void
+}
+
 !5 = !{!6, !6, i64 0}
 !6 = !{!"double", !7, i64 0}
 !7 = !{!"omnipotent char", !8, i64 0}