Implement interpretation of i64x2.bitmask (#3982)

Like a few other SIMD operations, this i64x2.bitmask had not been implemented in
the interpreter yet. Unlike the others, i64x2.bitmask has type i32 rather than
type v128, so Precompute was not skipping it, leading to a crash, as in
https://github.com/emscripten-core/emscripten/issues/14629. Fix the problem by
implementing i64x2.bitmask in the interpreter.

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,