Index: llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
===================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
@@ -549,6 +549,11 @@
 defm XOR : SIMDBitwise<xor, "xor", 79>;
 } // isCommutable = 1
 
+// Bitwise logic: v128.andnot
+def andnot : PatFrag<(ops node:$left, node:$right), (and $left, (vnot $right))>;
+let Predicates = [HasUnimplementedSIMD128] in
+defm ANDNOT : SIMDBitwise<andnot, "andnot", 216>;
+
 // Bitwise select: v128.bitselect
 foreach vec_t = [v16i8, v8i16, v4i32, v2i64, v4f32, v2f64] in
   defm BITSELECT_#vec_t :
Index: llvm/trunk/test/CodeGen/WebAssembly/simd-arith.ll
===================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/simd-arith.ll
+++ llvm/trunk/test/CodeGen/WebAssembly/simd-arith.ll
@@ -223,6 +223,23 @@
   ret <16 x i8> %a
 }
 
+; CHECK-LABEL: andnot_v16i8:
+; NO-SIMD128-NOT: v128
+; SIMD128-VM-NOT: v128.andnot
+; SIMD128-NEXT: .functype andnot_v16i8 (v128, v128) -> (v128){{$}}
+; SIMD128-SLOW-NEXT: v128.andnot $push[[R:[0-9]+]]=, $0, $1{{$}}
+; SIMD128-SLOW-NEXT: return $pop[[R]]{{$}}
+; SIMD128-FAST-NEXT: v128.not
+; SIMD128-FAST-NEXT: v128.and
+; SIMD128-FAST-NEXT: return
+define <16 x i8> @andnot_v16i8(<16 x i8> %x, <16 x i8> %y) {
+ %inv_y = xor <16 x i8> %y,
+   <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1,
+    i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
+ %a = and <16 x i8> %x, %inv_y
+ ret <16 x i8> %a
+}
+
 ; CHECK-LABEL: bitselect_v16i8:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-NEXT: .functype bitselect_v16i8 (v128, v128, v128) -> (v128){{$}}
@@ -445,6 +462,22 @@
   ret <8 x i16> %a
 }
 
+; CHECK-LABEL: andnot_v8i16:
+; SIMD128-VM-NOT: v128.andnot
+; NO-SIMD128-NOT: v128
+; SIMD128-NEXT: .functype andnot_v8i16 (v128, v128) -> (v128){{$}}
+; SIMD128-SLOW-NEXT: v128.andnot $push[[R:[0-9]+]]=, $0, $1{{$}}
+; SIMD128-SLOW-NEXT: return $pop[[R]]{{$}}
+; SIMD128-FAST-NEXT: v128.not
+; SIMD128-FAST-NEXT: v128.and
+; SIMD128-FAST-NEXT: return
+define <8 x i16> @andnot_v8i16(<8 x i16> %x, <8 x i16> %y) {
+ %inv_y = xor <8 x i16> %y,
+   <i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1>
+ %a = and <8 x i16> %x, %inv_y
+ ret <8 x i16> %a
+}
+
 ; CHECK-LABEL: bitselect_v8i16:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-NEXT: .functype bitselect_v8i16 (v128, v128, v128) -> (v128){{$}}
@@ -652,6 +685,21 @@
   ret <4 x i32> %a
 }
 
+; CHECK-LABEL: andnot_v4i32:
+; SIMD128-VM-NOT: v128.andnot
+; NO-SIMD128-NOT: v128
+; SIMD128-NEXT: .functype andnot_v4i32 (v128, v128) -> (v128){{$}}
+; SIMD128-SLOW-NEXT: v128.andnot $push[[R:[0-9]+]]=, $0, $1{{$}}
+; SIMD128-SLOW-NEXT: return $pop[[R]]{{$}}
+; SIMD128-FAST-NEXT: v128.not
+; SIMD128-FAST-NEXT: v128.and
+; SIMD128-FAST-NEXT: return
+define <4 x i32> @andnot_v4i32(<4 x i32> %x, <4 x i32> %y) {
+ %inv_y = xor <4 x i32> %y, <i32 -1, i32 -1, i32 -1, i32 -1>
+ %a = and <4 x i32> %x, %inv_y
+ ret <4 x i32> %a
+}
+
 ; CHECK-LABEL: bitselect_v4i32:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-NEXT: .functype bitselect_v4i32 (v128, v128, v128) -> (v128){{$}}
@@ -962,6 +1010,21 @@
   ret <2 x i64> %a
 }
 
+; CHECK-LABEL: andnot_v2i64:
+; SIMD128-VM-NOT: v128.andnot
+; NO-SIMD128-NOT: v128
+; SIMD128-NEXT: .functype andnot_v2i64 (v128, v128) -> (v128){{$}}
+; SIMD128-SLOW-NEXT: v128.andnot $push[[R:[0-9]+]]=, $0, $1{{$}}
+; SIMD128-SLOW-NEXT: return $pop[[R]]{{$}}
+; SIMD128-FAST-NEXT: v128.not
+; SIMD128-FAST-NEXT: v128.and
+; SIMD128-FAST-NEXT: return
+define <2 x i64> @andnot_v2i64(<2 x i64> %x, <2 x i64> %y) {
+ %inv_y = xor <2 x i64> %y, <i64 -1, i64 -1>
+ %a = and <2 x i64> %x, %inv_y
+ ret <2 x i64> %a
+}
+
 ; CHECK-LABEL: bitselect_v2i64:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-VM-NOT: v128
Index: llvm/trunk/test/MC/WebAssembly/simd-encodings.s
===================================================================
--- llvm/trunk/test/MC/WebAssembly/simd-encodings.s
+++ llvm/trunk/test/MC/WebAssembly/simd-encodings.s
@@ -529,4 +529,7 @@
     # CHECK: i64x2.load32x2_u 32 # encoding: [0xfd,0xd7,0x01,0x03,0x20]
     i64x2.load32x2_u 32
 
+    # CHECK: v128.andnot # encoding: [0xfd,0xd8,0x01]
+    v128.andnot
+
     end_function