3 files changed, 12 insertions, 1 deletions
diff --git a/src/literal.h b/src/literal.h
index 1dd013c4c..965ec157c 100644
--- a/src/literal.h
+++ b/src/literal.h
@@ -570,6 +570,7 @@ public:
   Literal extMulHighUI32x4(const Literal& other) const;
   Literal absI64x2() const;
   Literal negI64x2() const;
+  Literal bitmaskI64x2() const;
   Literal allTrueI64x2() const;
   Literal shlI64x2(const Literal& other) const;
   Literal shrSI64x2(const Literal& other) const;
diff --git a/src/wasm-interpreter.h b/src/wasm-interpreter.h
index 77b055fd1..8870e24dd 100644
--- a/src/wasm-interpreter.h
+++ b/src/wasm-interpreter.h
@@ -500,7 +500,7 @@ public:
       case AllTrueVecI64x2:
         return value.allTrueI64x2();
       case BitmaskVecI64x2:
-        WASM_UNREACHABLE("unimp");
+        return value.bitmaskI64x2();
       case AbsVecF32x4:
         return value.absF32x4();
       case NegVecF32x4:
diff --git a/src/wasm/literal.cpp b/src/wasm/literal.cpp
index 151ea83e5..c3a2ddf7a 100644
--- a/src/wasm/literal.cpp
+++ b/src/wasm/literal.cpp
@@ -1868,6 +1868,16 @@ Literal Literal::bitmaskI32x4() const {
 Literal Literal::allTrueI64x2() const {
   return all_true<2, &Literal::getLanesI64x2>(*this);
 }
+Literal Literal::bitmaskI64x2() const {
+  uint32_t result = 0;
+  LaneArray<2> lanes = getLanesI64x2();
+  for (size_t i = 0; i < 2; ++i) {
+    if (lanes[i].geti64() & (1ll << 63)) {
+      result = result | (1 << i);
+    }
+  }
+  return Literal(result);
+}
 
 template<int Lanes,
          LaneArray<Lanes> (Literal::*IntoLanes)() const,