diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -157,11 +157,9 @@
     setOperationAction(ISD::MUL, MVT::v16i8, Expand);
 
     // There is no vector conditional select instruction
-    // TODO: Implement SELECT_V128
-    for (auto Op : {ISD::SELECT_CC, ISD::SELECT})
-      for (auto T : {MVT::v16i8, MVT::v8i16, MVT::v4i32, MVT::v4f32, MVT::v2i64,
-                     MVT::v2f64})
-        setOperationAction(Op, T, Expand);
+    for (auto T : {MVT::v16i8, MVT::v8i16, MVT::v4i32, MVT::v4f32, MVT::v2i64,
+                   MVT::v2f64})
+      setOperationAction(ISD::SELECT_CC, T, Expand);
 
     // Expand integer operations supported for scalars but not SIMD
     for (auto Op : {ISD::CTLZ, ISD::CTTZ, ISD::CTPOP, ISD::SDIV, ISD::UDIV,
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
@@ -584,6 +584,37 @@
               V128:$v1, V128:$v2, V128:$c
             )>;
 
+// MVP select on v128 values
+foreach vec_t = [v16i8, v8i16, v4i32, v2i64, v4f32, v2f64] in {
+defm SELECT_#vec_t : I<(outs V128:$dst), (ins V128:$lhs, V128:$rhs, I32:$cond),
+                    (outs), (ins),
+                    [(set V128:$dst,
+                       (select I32:$cond,
+                         (vec_t V128:$lhs), (vec_t V128:$rhs)
+                       )
+                    )],
+                    "v128.select\t$dst, $lhs, $rhs, $cond",
+                    "v128.select", 0x1b>;
+
+// ISD::SELECT requires its operand to conform to getBooleanContents, but
+// WebAssembly's select interprets any non-zero value as true, so we can fold
+// a setne with 0 into a select.
+def : Pat<(select
+            (i32 (setne I32:$cond, 0)), (vec_t V128:$lhs), (vec_t V128:$rhs)
+          ),
+          (!cast<Instruction>("SELECT_"#vec_t)
+            V128:$lhs, V128:$rhs, I32:$cond
+          )>;
+
+// And again, this time with seteq instead of setne and the arms reversed.
+def : Pat<(select
+            (i32 (seteq I32:$cond, 0)), (vec_t V128:$lhs), (vec_t V128:$rhs)
+          ),
+          (!cast<Instruction>("SELECT_"#vec_t)
+            V128:$rhs, V128:$lhs, I32:$cond
+          )>;
+} // foreach vec_t
+
 //===----------------------------------------------------------------------===//
 // Integer unary arithmetic
 //===----------------------------------------------------------------------===//
diff --git a/llvm/test/CodeGen/WebAssembly/simd-select.ll b/llvm/test/CodeGen/WebAssembly/simd-select.ll
--- a/llvm/test/CodeGen/WebAssembly/simd-select.ll
+++ b/llvm/test/CodeGen/WebAssembly/simd-select.ll
@@ -49,12 +49,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i8x16.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %res = select i1 %c, <16 x i8> %x, <16 x i8> %y
   ret <16 x i8> %res
@@ -67,10 +63,9 @@
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.const 31
-; CHECK-NEXT:    i32.shr_s
-; CHECK-NEXT:    i8x16.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    i32.const 0
+; CHECK-NEXT:    i32.lt_s
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp slt i32 %i, 0
   %res = select i1 %c, <16 x i8> %x, <16 x i8> %y
@@ -83,12 +78,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i8x16.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp ne i32 %i, 0
   %res = select i1 %c, <16 x i8> %x, <16 x i8> %y
@@ -99,14 +90,10 @@
 ; CHECK-LABEL: select_eq_v16i8:
 ; CHECK:         .functype select_eq_v16i8 (i32, v128, v128) -> (v128)
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const 0
-; CHECK-NEXT:    i32.const -1
+; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i8x16.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp eq i32 %i, 0
   %res = select i1 %c, <16 x i8> %x, <16 x i8> %y
@@ -153,12 +140,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i16x8.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %res = select i1 %c, <8 x i16> %x, <8 x i16> %y
   ret <8 x i16> %res
@@ -171,10 +154,9 @@
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.const 31
-; CHECK-NEXT:    i32.shr_s
-; CHECK-NEXT:    i16x8.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    i32.const 0
+; CHECK-NEXT:    i32.lt_s
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp slt i32 %i, 0
   %res = select i1 %c, <8 x i16> %x, <8 x i16> %y
@@ -187,12 +169,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i16x8.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp ne i32 %i, 0
   %res = select i1 %c, <8 x i16> %x, <8 x i16> %y
@@ -203,14 +181,10 @@
 ; CHECK-LABEL: select_eq_v8i16:
 ; CHECK:         .functype select_eq_v8i16 (i32, v128, v128) -> (v128)
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const 0
-; CHECK-NEXT:    i32.const -1
+; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i16x8.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp eq i32 %i, 0
   %res = select i1 %c, <8 x i16> %x, <8 x i16> %y
@@ -257,12 +231,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %res = select i1 %c, <4 x i32> %x, <4 x i32> %y
   ret <4 x i32> %res
@@ -275,10 +245,9 @@
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.const 31
-; CHECK-NEXT:    i32.shr_s
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    i32.const 0
+; CHECK-NEXT:    i32.lt_s
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp slt i32 %i, 0
   %res = select i1 %c, <4 x i32> %x, <4 x i32> %y
@@ -291,12 +260,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp ne i32 %i, 0
   %res = select i1 %c, <4 x i32> %x, <4 x i32> %y
@@ -307,14 +272,10 @@
 ; CHECK-LABEL: select_eq_v4i32:
 ; CHECK:         .functype select_eq_v4i32 (i32, v128, v128) -> (v128)
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const 0
-; CHECK-NEXT:    i32.const -1
+; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp eq i32 %i, 0
   %res = select i1 %c, <4 x i32> %x, <4 x i32> %y
@@ -376,12 +337,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const -1
-; CHECK-NEXT:    i64.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %res = select i1 %c, <2 x i64> %x, <2 x i64> %y
   ret <2 x i64> %res
@@ -393,14 +350,10 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const -1
-; CHECK-NEXT:    i64.const 0
 ; CHECK-NEXT:    local.get 0
 ; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    i32.lt_s
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp slt i32 %i, 0
   %res = select i1 %c, <2 x i64> %x, <2 x i64> %y
@@ -413,12 +366,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const -1
-; CHECK-NEXT:    i64.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp ne i32 %i, 0
   %res = select i1 %c, <2 x i64> %x, <2 x i64> %y
@@ -429,14 +378,10 @@
 ; CHECK-LABEL: select_eq_v2i64:
 ; CHECK:         .functype select_eq_v2i64 (i32, v128, v128) -> (v128)
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const 0
-; CHECK-NEXT:    i64.const -1
+; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp eq i32 %i, 0
   %res = select i1 %c, <2 x i64> %x, <2 x i64> %y
@@ -483,12 +428,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %res = select i1 %c, <4 x float> %x, <4 x float> %y
   ret <4 x float> %res
@@ -501,10 +442,9 @@
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.const 31
-; CHECK-NEXT:    i32.shr_s
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    i32.const 0
+; CHECK-NEXT:    i32.lt_s
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp slt i32 %i, 0
   %res = select i1 %c, <4 x float> %x, <4 x float> %y
@@ -517,12 +457,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const -1
-; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp ne i32 %i, 0
   %res = select i1 %c, <4 x float> %x, <4 x float> %y
@@ -533,14 +469,10 @@
 ; CHECK-LABEL: select_eq_v4f32:
 ; CHECK:         .functype select_eq_v4f32 (i32, v128, v128) -> (v128)
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i32.const 0
-; CHECK-NEXT:    i32.const -1
+; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i32.select
-; CHECK-NEXT:    i32x4.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp eq i32 %i, 0
   %res = select i1 %c, <4 x float> %x, <4 x float> %y
@@ -587,12 +519,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const -1
-; CHECK-NEXT:    i64.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %res = select i1 %c, <2 x double> %x, <2 x double> %y
   ret <2 x double> %res
@@ -604,14 +532,10 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const -1
-; CHECK-NEXT:    i64.const 0
 ; CHECK-NEXT:    local.get 0
 ; CHECK-NEXT:    i32.const 0
 ; CHECK-NEXT:    i32.lt_s
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp slt i32 %i, 0
   %res = select i1 %c, <2 x double> %x, <2 x double> %y
@@ -624,12 +548,8 @@
 ; CHECK-NEXT:  # %bb.0:
 ; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const -1
-; CHECK-NEXT:    i64.const 0
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp ne i32 %i, 0
   %res = select i1 %c, <2 x double> %x, <2 x double> %y
@@ -640,14 +560,10 @@
 ; CHECK-LABEL: select_eq_v2f64:
 ; CHECK:         .functype select_eq_v2f64 (i32, v128, v128) -> (v128)
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 2
-; CHECK-NEXT:    i64.const 0
-; CHECK-NEXT:    i64.const -1
+; CHECK-NEXT:    local.get 1
 ; CHECK-NEXT:    local.get 0
-; CHECK-NEXT:    i64.select
-; CHECK-NEXT:    i64x2.splat
-; CHECK-NEXT:    v128.bitselect
+; CHECK-NEXT:    v128.select
 ; CHECK-NEXT:    # fallthrough-return
   %c = icmp eq i32 %i, 0
   %res = select i1 %c, <2 x double> %x, <2 x double> %y