diff --git a/clang/include/clang/Basic/BuiltinsWebAssembly.def b/clang/include/clang/Basic/BuiltinsWebAssembly.def
--- a/clang/include/clang/Basic/BuiltinsWebAssembly.def
+++ b/clang/include/clang/Basic/BuiltinsWebAssembly.def
@@ -132,6 +132,8 @@
 TARGET_BUILTIN(__builtin_wasm_min_f64x2, "V2dV2dV2d", "nc", "unimplemented-simd128")
 TARGET_BUILTIN(__builtin_wasm_max_f64x2, "V2dV2dV2d", "nc", "unimplemented-simd128")
 
+TARGET_BUILTIN(__builtin_wasm_dot_s_i32x4_i16x8, "V4iV8s", "nc", "simd128")
+
 TARGET_BUILTIN(__builtin_wasm_sqrt_f32x4, "V4fV4f", "nc", "unimplemented-simd128")
 TARGET_BUILTIN(__builtin_wasm_sqrt_f64x2, "V2dV2d", "nc", "unimplemented-simd128")
 
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -14360,6 +14360,11 @@
     Function *Callee = CGM.getIntrinsic(IntNo, ConvertType(E->getType()));
     return Builder.CreateCall(Callee, {LHS, RHS});
   }
+  case WebAssembly::BI__builtin_wasm_dot_s_i32x4_i16x8: {
+    Value *Vec = EmitScalarExpr(E->getArg(0));
+    Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_dot);
+    return Builder.CreateCall(Callee, {Vec});
+  }
   case WebAssembly::BI__builtin_wasm_any_true_i8x16:
   case WebAssembly::BI__builtin_wasm_any_true_i16x8:
   case WebAssembly::BI__builtin_wasm_any_true_i32x4:
diff --git a/clang/test/CodeGen/builtins-wasm.c b/clang/test/CodeGen/builtins-wasm.c
--- a/clang/test/CodeGen/builtins-wasm.c
+++ b/clang/test/CodeGen/builtins-wasm.c
@@ -436,6 +436,12 @@
   // WEBASSEMBLY-NEXT: ret
 }
 
+i32x4 dot_i16x8_s(i16x8 x) {
+  return __builtin_wasm_dot_s_i32x4_i16x8(x);
+  // WEBASSEMBLY: call <4 x i32> @llvm.wasm.dot(<8 x i16> %x)
+  // WEBASSEMBLY-NEXT: ret
+}
+
 i32x4 bitselect(i32x4 x, i32x4 y, i32x4 c) {
   return __builtin_wasm_bitselect(x, y, c);
   // WEBASSEMBLY: call <4 x i32> @llvm.wasm.bitselect.v4i32(
diff --git a/llvm/include/llvm/IR/IntrinsicsWebAssembly.td b/llvm/include/llvm/IR/IntrinsicsWebAssembly.td
--- a/llvm/include/llvm/IR/IntrinsicsWebAssembly.td
+++ b/llvm/include/llvm/IR/IntrinsicsWebAssembly.td
@@ -152,6 +152,10 @@
   Intrinsic<[llvm_anyvector_ty],
             [LLVMMatchType<0>, LLVMMatchType<0>, LLVMMatchType<0>],
             [IntrNoMem, IntrSpeculatable]>;
+def int_wasm_dot :
+  Intrinsic<[llvm_v4i32_ty],
+            [llvm_v8i16_ty],
+            [IntrNoMem, IntrSpeculatable]>;
 def int_wasm_narrow_signed :
   Intrinsic<[llvm_anyvector_ty],
             [llvm_anyvector_ty, LLVMMatchType<1>],
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
@@ -639,6 +639,11 @@
           (i32 (!cast<NI>(reduction[1]#"_"#ty) (ty V128:$x)))>;
 }
 
+// Widening dot product: i32x4.dot_i16x8_s
+defm DOT : SIMD_I<(outs V128:$dst), (ins V128:$vec), (outs), (ins),
+                  [(set V128:$dst, (v4i32 (int_wasm_dot V128:$vec)))],
+                  "i32x4.dot_i16x8_s\t$dst, $vec", "i32x4.dot_i16x8_s", 217>;
+
 //===----------------------------------------------------------------------===//
 // Bit shifts
 //===----------------------------------------------------------------------===//
diff --git a/llvm/test/CodeGen/WebAssembly/simd-intrinsics.ll b/llvm/test/CodeGen/WebAssembly/simd-intrinsics.ll
--- a/llvm/test/CodeGen/WebAssembly/simd-intrinsics.ll
+++ b/llvm/test/CodeGen/WebAssembly/simd-intrinsics.ll
@@ -407,6 +407,16 @@
   ret i32 %a
 }
 
+; CHECK-LABEL: dot:
+; SIMD128-NEXT: .functype dot (v128) -> (v128){{$}}
+; SIMD128-NEXT: i32x4.dot_i16x8_s $push[[R:[0-9]+]]=, $0{{$}}
+; SIMD128-NEXT: return $pop[[R]]{{$}}
+declare <4 x i32> @llvm.wasm.dot(<8 x i16>)
+define <4 x i32> @dot(<8 x i16> %x) {
+  %a = call <4 x i32> @llvm.wasm.dot(<8 x i16> %x)
+  ret <4 x i32> %a
+}
+
 ; CHECK-LABEL: bitselect_v4i32:
 ; SIMD128-NEXT: .functype bitselect_v4i32 (v128, v128, v128) -> (v128){{$}}
 ; SIMD128-NEXT: v128.bitselect $push[[R:[0-9]+]]=, $0, $1, $2{{$}}
diff --git a/llvm/test/MC/WebAssembly/simd-encodings.s b/llvm/test/MC/WebAssembly/simd-encodings.s
--- a/llvm/test/MC/WebAssembly/simd-encodings.s
+++ b/llvm/test/MC/WebAssembly/simd-encodings.s
@@ -571,4 +571,7 @@
     # CHECK: v128.andnot # encoding: [0xfd,0xd8,0x01]
     v128.andnot
 
+    # CHECK: i32x4.dot_i16x8_s # encoding: [0xfd,0xd9,0x01]
+    i32x4.dot_i16x8_s
+
     end_function