wasm2js: Add basic reference operations (#6648)

This adds ref.eq, ref.null, ref.is_null, ref.func.

2 files changed, 10 insertions, 2 deletions

diff --git a/src/emscripten-optimizer/optimizer-shared.cpp b/src/emscripten-optimizer/optimizer-shared.cpp
index 8208f6f47..773c5d9fc 100644
--- a/src/emscripten-optimizer/optimizer-shared.cpp
+++ b/src/emscripten-optimizer/optimizer-shared.cpp
@@ -104,6 +104,11 @@ Ref makeJsCoercedZero(JsType type) {
   abort();
 }
 
+bool needsJsCoercion(JsType type) {
+  // References need no coercion, but everything else does.
+  return type != JS_REF;
+}
+
 Ref makeJsCoercion(Ref node, JsType type) {
   switch (type) {
     case JS_INT:
@@ -122,10 +127,11 @@ Ref makeJsCoercion(Ref node, JsType type) {
       return ValueBuilder::makeCall(SIMD_INT16X8_CHECK, node);
     case JS_INT32X4:
       return ValueBuilder::makeCall(SIMD_INT32X4_CHECK, node);
+    case JS_REF:
     case JS_NONE:
     default:
-      // non-validating code, emit nothing XXX this is dangerous, we should only
-      // allow this when we know we are not validating
+      // No coercion is needed.
+      // TODO see if JS_NONE is actually used here.
       return node;
   }
 }
diff --git a/src/emscripten-optimizer/optimizer.h b/src/emscripten-optimizer/optimizer.h
index a27fe25eb..6347c194c 100644
--- a/src/emscripten-optimizer/optimizer.h
+++ b/src/emscripten-optimizer/optimizer.h
@@ -39,6 +39,7 @@ enum JsType {
   JS_INT16X8,
   JS_INT32X4,
   JS_INT64,
+  JS_REF,
   JS_NONE // number of types
 };
 
@@ -51,6 +52,7 @@ enum JsSign {
 };
 
 cashew::Ref makeJsCoercedZero(JsType type);
+bool needsJsCoercion(JsType type);
 cashew::Ref makeJsCoercion(cashew::Ref node, JsType type);
 cashew::Ref makeSigning(cashew::Ref node, JsSign sign);