Index: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -370,6 +370,7 @@
 
   setOperationAction(ISD::CTPOP, MVT::i32, Custom);
   setOperationAction(ISD::CTPOP, MVT::i64, Custom);
+  setOperationAction(ISD::CTPOP, MVT::i128, Custom);
 
   setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
   setOperationAction(ISD::SDIVREM, MVT::i64, Expand);
@@ -5420,6 +5421,15 @@
     if (VT == MVT::i64)
       UaddLV = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, UaddLV);
     return UaddLV;
+  } else if (VT == MVT::i128) {
+    Val = DAG.getNode(ISD::BITCAST, DL, MVT::v16i8, Val);
+
+    SDValue CtPop = DAG.getNode(ISD::CTPOP, DL, MVT::v16i8, Val);
+    SDValue UaddLV = DAG.getNode(
+        ISD::INTRINSIC_WO_CHAIN, DL, MVT::i32,
+        DAG.getConstant(Intrinsic::aarch64_neon_uaddlv, DL, MVT::i32), CtPop);
+
+    return DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i128, UaddLV);
   }
 
   assert((VT == MVT::v1i64 || VT == MVT::v2i64 || VT == MVT::v2i32 ||
@@ -13963,6 +13973,9 @@
     Results.push_back(LowerVECREDUCE(SDValue(N, 0), DAG));
     return;
 
+  case ISD::CTPOP:
+    Results.push_back(LowerCTPOP(SDValue(N, 0), DAG));
+    return;
   case AArch64ISD::SADDV:
     ReplaceReductionResults(N, Results, DAG, ISD::ADD, AArch64ISD::SADDV);
     return;
Index: llvm/test/CodeGen/AArch64/popcount.ll
===================================================================
--- llvm/test/CodeGen/AArch64/popcount.ll
+++ llvm/test/CodeGen/AArch64/popcount.ll
@@ -5,19 +5,16 @@
 define i8 @popcount128(i128* nocapture nonnull readonly %0) {
 ; CHECK-LABEL: popcount128:
 ; CHECK:       // %bb.0: // %Entry
-; CHECK-NEXT:    ldr d0, [x0, #8]
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w8, s2
+; CHECK-NEXT:    ldr x8, [x0, #8]
 ; CHECK-NEXT:    ldr d0, [x0]
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w9, s2
-; CHECK-NEXT:    add w0, w9, w8
+; CHECK-NEXT:    // implicit-def: $q1
+; CHECK-NEXT:    mov v1.16b, v0.16b
+; CHECK-NEXT:    mov v1.d[1], x8
+; CHECK-NEXT:    cnt v0.16b, v1.16b
+; CHECK-NEXT:    uaddlv h0, v0.16b
+; CHECK-NEXT:    // implicit-def: $q1
+; CHECK-NEXT:    mov v1.16b, v0.16b
+; CHECK-NEXT:    fmov w0, s1
 ; CHECK-NEXT:    ret
 Entry:
   %1 = load i128, i128* %0, align 16
@@ -33,33 +30,27 @@
 define i16 @popcount256(i256* nocapture nonnull readonly %0) {
 ; CHECK-LABEL: popcount256:
 ; CHECK:       // %bb.0: // %Entry
-; CHECK-NEXT:    ldr d0, [x0, #24]
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w8, s2
+; CHECK-NEXT:    ldr x8, [x0, #8]
+; CHECK-NEXT:    ldr x9, [x0, #24]
 ; CHECK-NEXT:    ldr d0, [x0, #16]
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w9, s2
-; CHECK-NEXT:    add w8, w9, w8
-; CHECK-NEXT:    ldr d0, [x0, #8]
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w9, s2
+; CHECK-NEXT:    // implicit-def: $q1
+; CHECK-NEXT:    mov v1.16b, v0.16b
+; CHECK-NEXT:    mov v1.d[1], x9
+; CHECK-NEXT:    cnt v0.16b, v1.16b
+; CHECK-NEXT:    uaddlv h0, v0.16b
+; CHECK-NEXT:    // implicit-def: $q1
+; CHECK-NEXT:    mov v1.16b, v0.16b
+; CHECK-NEXT:    fmov w9, s1
 ; CHECK-NEXT:    ldr d0, [x0]
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w10, s2
-; CHECK-NEXT:    add w9, w10, w9
-; CHECK-NEXT:    add w0, w9, w8
+; CHECK-NEXT:    // implicit-def: $q1
+; CHECK-NEXT:    mov v1.16b, v0.16b
+; CHECK-NEXT:    mov v1.d[1], x8
+; CHECK-NEXT:    cnt v0.16b, v1.16b
+; CHECK-NEXT:    uaddlv h0, v0.16b
+; CHECK-NEXT:    // implicit-def: $q1
+; CHECK-NEXT:    mov v1.16b, v0.16b
+; CHECK-NEXT:    fmov w8, s1
+; CHECK-NEXT:    add w0, w8, w9
 ; CHECK-NEXT:    ret
 Entry:
   %1 = load i256, i256* %0, align 16
@@ -74,23 +65,17 @@
 define <1 x i128> @popcount1x128(<1 x i128> %0) {
 ; CHECK-LABEL: popcount1x128:
 ; CHECK:       // %bb.0: // %Entry
-; CHECK-NEXT:    fmov d0, x1
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w2, s2
-; CHECK-NEXT:    mov w8, w2
+; CHECK-NEXT:    // implicit-def: $q0
 ; CHECK-NEXT:    fmov d0, x0
-; CHECK-NEXT:    cnt v0.8b, v0.8b
-; CHECK-NEXT:    uaddlv h1, v0.8b
-; CHECK-NEXT:    // implicit-def: $q2
-; CHECK-NEXT:    mov v2.16b, v1.16b
-; CHECK-NEXT:    fmov w2, s2
-; CHECK-NEXT:    mov w9, w2
-; CHECK-NEXT:    add x0, x9, x8
-; CHECK-NEXT:    movi v2.2d, #0000000000000000
-; CHECK-NEXT:    mov x1, v2.d[1]
+; CHECK-NEXT:    mov v0.d[1], x1
+; CHECK-NEXT:    cnt v0.16b, v0.16b
+; CHECK-NEXT:    uaddlv h0, v0.16b
+; CHECK-NEXT:    // implicit-def: $q1
+; CHECK-NEXT:    mov v1.16b, v0.16b
+; CHECK-NEXT:    fmov w0, s1
+; CHECK-NEXT:    // kill: def $x0 killed $w0
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
+; CHECK-NEXT:    mov x1, v0.d[1]
 ; CHECK-NEXT:    ret
 Entry:
   %1 = tail call <1 x i128> @llvm.ctpop.v1.i128(<1 x i128> %0)