fix

Author: kripken

src/asm2wasm.h

@@ -774,18 +774,22 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
         }
       }
       auto importResult = getModule()->getImport(curr->target)->functionType->result;
-      if (isConcreteWasmType(curr->type)) {
-        if (curr->type != importResult) {
-          assert(importResult == f64); // we generalized because we had to
+      if (curr->type != importResult) {
+        if (importResult == f64) {
+          // we use a JS f64 value which is the most general, and convert to it
           switch (curr->type) {
             case i32: replaceCurrent(parent->builder.makeUnary(TruncSFloat64ToInt32, curr)); break;
             case f32: replaceCurrent(parent->builder.makeUnary(DemoteFloat64, curr)); break;
-            default: {} // f64, unreachable, etc., are all good
+            case none: replaceCurrent(parent->builder.makeDrop(curr)); break;
+            default: WASM_UNREACHABLE();
           }
-          curr->type = importResult;
+        } else {
+          assert(curr->type == none);
+          // we don't want a return value here, but the import does provide one
+          replaceCurrent(parent->builder.makeDrop(curr));
         }
+        curr->type = importResult;
       }
-
       fixParents();
     }