Index: llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
===================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
@@ -134,6 +134,29 @@
   defm "" : SIMDBinary<v4i32, "v128", node, name, simdop>;
   defm "" : SIMDBinary<v2i64, "v128", node, name, simdop>;
 }
+multiclass SIMDNeg<ValueType vec_t, string vec, PatFrag splat_pat,
+                   ValueType lane_t, SDNode node, dag lane, bits<32> simdop> {
+  defm NEG_#vec_t : SIMD_I<(outs V128:$dst), (ins V128:$vec),
+                           (outs), (ins),
+                           [(set
+                             (vec_t V128:$dst),
+                             (vec_t (node
+                               (vec_t (splat_pat lane)),
+                               (vec_t V128:$vec)
+                             ))
+                           )],
+                           vec#".neg\t$dst, $vec", vec#".neg", simdop>;
+}
+multiclass SIMDNegInt<ValueType vec_t, string vec, PatFrag splat_pat,
+                      ValueType lane_t, bits<32> simdop> {
+  defm "" : SIMDNeg<vec_t, vec, splat_pat, lane_t, sub, (lane_t 0), simdop>;
+}
+def fpimm0 : FPImmLeaf<fAny, [{ return Imm.isExactlyValue(+0.0); }]>;
+multiclass SIMDNegFP<ValueType vec_t, string vec, PatFrag splat_pat,
+                     ValueType lane_t, bits<32> simdop> {
+  defm "" : SIMDNeg<vec_t, vec, splat_pat, lane_t, fsub, (lane_t fpimm0),
+                    simdop>;
+}
 multiclass SIMDNot<ValueType vec_t, PatFrag splat_pat, ValueType lane_t> {
   defm NOT_#vec_t : SIMD_I<(outs V128:$dst), (ins V128:$vec),
                            (outs), (ins),
@@ -281,6 +304,13 @@
 defm SUB : SIMDBinaryFP<fsub, "sub", 124>;
 defm DIV : SIMDBinaryFP<fdiv, "div", 126>;
 
+defm "" : SIMDNegInt<v16i8, "i8x16", splat16, i32, 35>;
+defm "" : SIMDNegInt<v8i16, "i16x8", splat8, i32, 36>;
+defm "" : SIMDNegInt<v4i32, "i32x4", splat4, i32, 37>;
+defm "" : SIMDNegInt<v2i64, "i64x2", splat2, i64, 38>;
+defm "" : SIMDNegFP<v4f32, "f32x4", splat4, f32, 114>;
+defm "" : SIMDNegFP<v2f64, "f64x2", splat2, f64, 115>;
+
 let isCommutable = 1 in {
 defm AND : SIMDBitwise<and, "and", 59>;
 defm OR : SIMDBitwise<or, "or", 60>;
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
@@ -46,6 +46,19 @@
   ret <16 x i8> %a
 }
 
+; CHECK-LABEL: neg_v16i8:
+; NO-SIMD128-NOT: i8x16
+; SIMD128-NEXT: .param v128{{$}}
+; SIMD128-NEXT: .result v128{{$}}
+; SIMD128-NEXT: i8x16.neg $push0=, $0{{$}}
+; SIMD128-NEXT: return $pop0{{$}}
+define <16 x i8> @neg_v16i8(<16 x i8> %x) {
+  %a = sub <16 x i8> <i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0,
+                      i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0>,
+                     %x
+  ret <16 x i8> %a
+}
+
 ; CHECK-LABEL: and_v16i8:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-NEXT: .param v128, v128{{$}}
@@ -129,6 +142,18 @@
   ret <8 x i16> %a
 }
 
+; CHECK-LABEL: neg_v8i16:
+; NO-SIMD128-NOT: i16x8
+; SIMD128-NEXT: .param v128{{$}}
+; SIMD128-NEXT: .result v128{{$}}
+; SIMD128-NEXT: i16x8.neg $push0=, $0{{$}}
+; SIMD128-NEXT: return $pop0{{$}}
+define <8 x i16> @neg_v8i16(<8 x i16> %x) {
+  %a = sub <8 x i16> <i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0>,
+                     %x
+  ret <8 x i16> %a
+}
+
 ; CHECK-LABEL: and_v8i16:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-NEXT: .param v128, v128{{$}}
@@ -210,6 +235,17 @@
   ret <4 x i32> %a
 }
 
+; CHECK-LABEL: neg_v4i32:
+; NO-SIMD128-NOT: i32x4
+; SIMD128-NEXT: .param v128{{$}}
+; SIMD128-NEXT: .result v128{{$}}
+; SIMD128-NEXT: i32x4.neg $push0=, $0{{$}}
+; SIMD128-NEXT: return $pop0{{$}}
+define <4 x i32> @neg_v4i32(<4 x i32> %x) {
+  %a = sub <4 x i32> <i32 0, i32 0, i32 0, i32 0>, %x
+  ret <4 x i32> %a
+}
+
 ; CHECK-LABEL: and_v4i32:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-NEXT: .param v128, v128{{$}}
@@ -293,6 +329,17 @@
   ret <2 x i64> %a
 }
 
+; CHECK-LABEL: neg_v2i64:
+; NO-SIMD128-NOT: i64x2
+; SIMD128-NEXT: .param v128{{$}}
+; SIMD128-NEXT: .result v128{{$}}
+; SIMD128-NEXT: i64x2.neg $push0=, $0{{$}}
+; SIMD128-NEXT: return $pop0{{$}}
+define <2 x i64> @neg_v2i64(<2 x i64> %x) {
+  %a = sub <2 x i64> <i64 0, i64 0>, %x
+  ret <2 x i64> %a
+}
+
 ; CHECK-LABEL: and_v2i64:
 ; NO-SIMD128-NOT: v128
 ; SIMD128-VM-NOT: v128
@@ -344,6 +391,17 @@
 ; ==============================================================================
 ; 4 x float
 ; ==============================================================================
+; CHECK-LABEL: neg_v4f32:
+; NO-SIMD128-NOT: f32x4
+; SIMD128-NEXT: .param v128{{$}}
+; SIMD128-NEXT: .result v128{{$}}
+; SIMD128-NEXT: f32x4.neg $push0=, $0{{$}}
+; SIMD128-NEXT: return $pop0{{$}}
+define <4 x float> @neg_v4f32(<4 x float> %x) {
+  %a = fsub <4 x float> <float 0., float 0., float 0., float 0.>, %x
+  ret <4 x float> %a
+}
+
 ; CHECK-LABEL: add_v4f32:
 ; NO-SIMD128-NOT: f32x4
 ; SIMD128-NEXT: .param v128, v128{{$}}
@@ -391,6 +449,17 @@
 ; ==============================================================================
 ; 2 x double
 ; ==============================================================================
+; CHECK-LABEL: neg_v2f64:
+; NO-SIMD128-NOT: f64x2
+; SIMD128-NEXT: .param v128{{$}}
+; SIMD128-NEXT: .result v128{{$}}
+; SIMD128-NEXT: f64x2.neg $push0=, $0{{$}}
+; SIMD128-NEXT: return $pop0{{$}}
+define <2 x double> @neg_v2f64(<2 x double> %x) {
+  %a = fsub <2 x double> <double 0., double 0.>, %x
+  ret <2 x double> %a
+}
+
 ; CHECK-LABEL: add_v2f64:
 ; NO-SIMD128-NOT: f64x2
 ; SIMD128-VM-NOT: f62x2
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
@@ -133,6 +133,18 @@
     # CHECK: i32x4.mul # encoding: [0xfd,0x22]
     i32x4.mul
 
+    # CHECK: i8x16.neg # encoding: [0xfd,0x23]
+    i8x16.neg
+
+    # CHECK: i16x8.neg # encoding: [0xfd,0x24]
+    i16x8.neg
+
+    # CHECK: i32x4.neg # encoding: [0xfd,0x25]
+    i32x4.neg
+
+    # CHECK: i64x2.neg # encoding: [0xfd,0x26]
+    i64x2.neg
+
     # CHECK: v128.and # encoding: [0xfd,0x3b]
     v128.and
 
@@ -271,6 +283,12 @@
     # CHECK: f64x2.ge # encoding: [0xfd,0x71]
     f64x2.ge
 
+    # CHECK: f32x4.neg # encoding: [0xfd,0x72]
+    f32x4.neg
+
+    # CHECK: f64x2.neg # encoding: [0xfd,0x73]
+    f64x2.neg
+
     # CHECK: f32x4.add # encoding: [0xfd,0x7a]
     f32x4.add