diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 40a26025232695..e450ef2d223abd 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -189,6 +189,11 @@ WebAssemblyTargetLowering::WebAssemblyTargetLowering(
         setOperationAction(Op, MVT::v2f64, Expand);
     }
 
+    // Expand operations not supported for i64x2 vectors
+    if (Subtarget->hasUnimplementedSIMD128())
+      for (unsigned CC = 0; CC < ISD::SETCC_INVALID; ++CC)
+        setCondCodeAction(static_cast<ISD::CondCode>(CC), MVT::v2i64, Custom);
+
     // Expand additional SIMD ops that V8 hasn't implemented yet
     if (!Subtarget->hasUnimplementedSIMD128()) {
       setOperationAction(ISD::FSQRT, MVT::v4f32, Expand);
@@ -1014,6 +1019,8 @@ SDValue WebAssemblyTargetLowering::LowerOperation(SDValue Op,
     return LowerBUILD_VECTOR(Op, DAG);
   case ISD::VECTOR_SHUFFLE:
     return LowerVECTOR_SHUFFLE(Op, DAG);
+  case ISD::SETCC:
+    return LowerSETCC(Op, DAG);
   case ISD::SHL:
   case ISD::SRA:
   case ISD::SRL:
@@ -1479,6 +1486,29 @@ WebAssemblyTargetLowering::LowerVECTOR_SHUFFLE(SDValue Op,
   return DAG.getNode(WebAssemblyISD::SHUFFLE, DL, Op.getValueType(), Ops);
 }
 
+SDValue WebAssemblyTargetLowering::LowerSETCC(SDValue Op,
+                                              SelectionDAG &DAG) const {
+  SDLoc DL(Op);
+  // The legalizer does not know how to expand the comparison modes of i64x2
+  // vectors because no comparison modes are supported. We could solve this by
+  // expanding all i64x2 SETCC nodes, but that seems to expand f64x2 SETCC nodes
+  // (which return i64x2 results) as well. So instead we manually unroll i64x2
+  // comparisons here.
+  assert(Subtarget->hasUnimplementedSIMD128());
+  assert(Op->getOperand(0)->getSimpleValueType(0) == MVT::v2i64);
+  SmallVector<SDValue, 2> LHS, RHS;
+  DAG.ExtractVectorElements(Op->getOperand(0), LHS);
+  DAG.ExtractVectorElements(Op->getOperand(1), RHS);
+  const SDValue &CC = Op->getOperand(2);
+  auto MakeLane = [&](unsigned I) {
+    return DAG.getNode(ISD::SELECT_CC, DL, MVT::i64, LHS[I], RHS[I],
+                       DAG.getConstant(uint64_t(-1), DL, MVT::i64),
+                       DAG.getConstant(uint64_t(0), DL, MVT::i64), CC);
+  };
+  return DAG.getBuildVector(Op->getValueType(0), DL,
+                            {MakeLane(0), MakeLane(1)});
+}
+
 SDValue
 WebAssemblyTargetLowering::LowerAccessVectorElement(SDValue Op,
                                                     SelectionDAG &DAG) const {
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h
index 4e0f7cf8974fb7..58e088a0ba503d 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h
@@ -116,6 +116,7 @@ class WebAssemblyTargetLowering final : public TargetLowering {
   SDValue LowerSIGN_EXTEND_INREG(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
+  SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerAccessVectorElement(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerShift(SDValue Op, SelectionDAG &DAG) const;
 };
diff --git a/llvm/test/CodeGen/WebAssembly/simd-comparisons.ll b/llvm/test/CodeGen/WebAssembly/simd-comparisons.ll
index 2decd38fa84a14..3b6af73eb15f83 100644
--- a/llvm/test/CodeGen/WebAssembly/simd-comparisons.ll
+++ b/llvm/test/CodeGen/WebAssembly/simd-comparisons.ll
@@ -637,6 +637,156 @@ define <4 x i32> @compare_sext_uge_v4i32 (<4 x i32> %x, <4 x i32> %y) {
   ret <4 x i32> %res
 }
 
+; CHECK-LABEL: compare_eq_v2i64:
+; SIMD128-NEXT: .functype compare_eq_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_eq_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp eq <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_eq_v2i64:
+; SIMD128-NEXT: .functype compare_sext_eq_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_eq_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp eq <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_ne_v2i64:
+; SIMD128-NEXT: .functype compare_ne_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_ne_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp ne <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_ne_v2i64:
+; SIMD128-NEXT: .functype compare_sext_ne_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_ne_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp ne <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_slt_v2i64:
+; SIMD128-NEXT: .functype compare_slt_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_slt_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp slt <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_slt_v2i64:
+; SIMD128-NEXT: .functype compare_sext_slt_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_slt_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp slt <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_ult_v2i64:
+; SIMD128-NEXT: .functype compare_ult_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_ult_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp ult <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_ult_v2i64:
+; SIMD128-NEXT: .functype compare_sext_ult_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_ult_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp ult <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_sle_v2i64:
+; SIMD128-NEXT: .functype compare_sle_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_sle_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp sle <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_sle_v2i64:
+; SIMD128-NEXT: .functype compare_sext_sle_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_sle_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp sle <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_ule_v2i64:
+; SIMD128-NEXT: .functype compare_ule_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_ule_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp ule <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_ule_v2i64:
+; SIMD128-NEXT: .functype compare_sext_ule_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_ule_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp ule <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_sgt_v2i64:
+; SIMD128-NEXT: .functype compare_sgt_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_sgt_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp sgt <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_sgt_v2i64:
+; SIMD128-NEXT: .functype compare_sext_sgt_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_sgt_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp sgt <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_ugt_v2i64:
+; SIMD128-NEXT: .functype compare_ugt_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_ugt_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp ugt <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_ugt_v2i64:
+; SIMD128-NEXT: .functype compare_sext_ugt_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_ugt_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp ugt <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_sge_v2i64:
+; SIMD128-NEXT: .functype compare_sge_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_sge_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp sge <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_sge_v2i64:
+; SIMD128-NEXT: .functype compare_sext_sge_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_sge_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp sge <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
+; CHECK-LABEL: compare_uge_v2i64:
+; SIMD128-NEXT: .functype compare_uge_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i1> @compare_uge_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %res = icmp uge <2 x i64> %x, %y
+  ret <2 x i1> %res
+}
+
+; CHECK-LABEL: compare_sext_uge_v2i64:
+; SIMD128-NEXT: .functype compare_sext_uge_v2i64 (v128, v128) -> (v128){{$}}
+define <2 x i64> @compare_sext_uge_v2i64 (<2 x i64> %x, <2 x i64> %y) {
+  %cmp = icmp uge <2 x i64> %x, %y
+  %res = sext <2 x i1> %cmp to <2 x i64>
+  ret <2 x i64> %res
+}
+
 ; CHECK-LABEL: compare_oeq_v4f32:
 ; NO-SIMD128-NOT: f32x4
 ; SIMD128-NEXT: .functype compare_oeq_v4f32 (v128, v128) -> (v128){{$}}