3 files changed, 28 insertions, 68 deletions

diff --git a/src/wasm/wasm-type.cpp b/src/wasm/wasm-type.cpp
index ffc18b9fd..d3c4c0fc4 100644
--- a/src/wasm/wasm-type.cpp
+++ b/src/wasm/wasm-type.cpp
@@ -415,7 +415,7 @@ bool Type::isDefaultable() const {
   // A variable can get a default value if its type is concrete (unreachable
   // and none have no values, hence no default), and if it's a reference, it
   // must be nullable.
-  return isConcrete() && (!isRef() || isNullable());
+  return isConcrete() && (!isRef() || isNullable()) && !isRtt();
 }
 
 bool Type::operator<(const Type& other) const {
diff --git a/test/passes/Oz_fuzz-exec_all-features.txt b/test/passes/Oz_fuzz-exec_all-features.txt
index b43681cdf..867179092 100644
--- a/test/passes/Oz_fuzz-exec_all-features.txt
+++ b/test/passes/Oz_fuzz-exec_all-features.txt
@@ -114,80 +114,46 @@
   )
  )
  (func $2 (; has Stack IR ;)
-  (local $0 (rtt ${mut:i32}))
-  (local $1 (rtt ${i32_f64}))
-  (local $2 (rtt ${i32_f64}))
-  (local $3 anyref)
-  (local.set $1
-   (rtt.sub ${i32_f64}
-    (local.tee $0
-     (rtt.canon ${mut:i32})
-    )
-   )
-  )
-  (local.set $2
-   (rtt.canon ${i32_f64})
-  )
+  (local $0 anyref)
   (call $log
-   (ref.is_null
-    (ref.cast ${mut:i32}
-     (ref.null ${mut:i32})
-     (local.get $0)
-    )
-   )
+   (i32.const 1)
   )
   (call $log
-   (ref.test ${mut:i32}
-    (ref.null ${mut:i32})
-    (local.get $0)
-   )
+   (i32.const 0)
   )
   (call $log
-   (ref.test ${mut:i32}
-    (array.new_with_rtt $[mut:i8]
-     (rtt.canon $[mut:i8])
-     (i32.const 10)
-     (i32.const 20)
-    )
-    (local.get $0)
-   )
+   (i32.const 0)
   )
   (call $log
-   (ref.test ${mut:i32}
-    (struct.new_default_with_rtt ${mut:i32}
-     (local.get $0)
-    )
-    (local.get $0)
-   )
+   (i32.const 1)
   )
   (call $log
-   (ref.test ${i32_f64}
-    (struct.new_default_with_rtt ${mut:i32}
-     (local.get $0)
-    )
-    (local.get $2)
-   )
+   (i32.const 0)
   )
   (call $log
    (ref.test ${i32_f64}
-    (local.tee $3
+    (local.tee $0
      (struct.new_default_with_rtt ${i32_f64}
-      (local.get $1)
+      (rtt.sub ${i32_f64}
+       (rtt.canon ${mut:i32})
+      )
      )
     )
-    (local.get $1)
+    (rtt.sub ${i32_f64}
+     (rtt.canon ${mut:i32})
+    )
    )
   )
   (call $log
    (ref.test ${i32_f64}
-    (local.get $3)
-    (local.get $2)
+    (local.get $0)
+    (rtt.canon ${i32_f64})
    )
   )
   (call $log
    (ref.test ${mut:i32}
-    (local.get $3)
     (local.get $0)
+    (rtt.canon ${mut:i32})
    )
   )
  )
diff --git a/test/passes/Oz_fuzz-exec_all-features.wast b/test/passes/Oz_fuzz-exec_all-features.wast
index 7d586cffc..d521ad377 100644
--- a/test/passes/Oz_fuzz-exec_all-features.wast
+++ b/test/passes/Oz_fuzz-exec_all-features.wast
@@ -69,20 +69,14 @@
   )
  )
  (func "rtts"
-  (local $x (rtt $struct))
-  (local $y (rtt $extendedstruct))
-  (local $z (rtt $extendedstruct))
   (local $any anyref)
-  (local.set $x (rtt.canon $struct))
-  (local.set $y (rtt.sub $extendedstruct (local.get $x)))
-  (local.set $z (rtt.canon $extendedstruct))
   ;; Casting null returns null.
   (call $log (ref.is_null
-   (ref.cast $struct (ref.null $struct) (local.get $x))
+   (ref.cast $struct (ref.null $struct) (rtt.canon $struct))
   ))
   ;; Testing null returns 0.
   (call $log
-   (ref.test $struct (ref.null $struct) (local.get $x))
+   (ref.test $struct (ref.null $struct) (rtt.canon $struct))
   )
   ;; Testing something completely wrong (struct vs array) returns 0.
   (call $log
@@ -92,52 +86,52 @@
      (i32.const 10)
      (i32.const 20)
     )
-    (local.get $x)
+    (rtt.canon $struct)
    )
   )
   ;; Testing a thing with the same RTT returns 1.
   (call $log
    (ref.test $struct
     (struct.new_default_with_rtt $struct
-     (local.get $x)
+     (rtt.canon $struct)
     )
-    (local.get $x)
+    (rtt.canon $struct)
    )
   )
   ;; A bad downcast returns 0: we create a struct, which is not a extendedstruct.
   (call $log
    (ref.test $extendedstruct
     (struct.new_default_with_rtt $struct
-     (local.get $x)
+     (rtt.canon $struct)
     )
-    (local.get $z)
+    (rtt.canon $extendedstruct)
    )
   )
   ;; Create a extendedstruct with RTT y, and upcast statically to anyref.
   (local.set $any
    (struct.new_default_with_rtt $extendedstruct
-    (local.get $y)
+    (rtt.sub $extendedstruct (rtt.canon $struct))
    )
   )
   ;; Casting to y, the exact same RTT, works.
   (call $log
    (ref.test $extendedstruct
     (local.get $any)
-    (local.get $y)
+    (rtt.sub $extendedstruct (rtt.canon $struct))
    )
   )
   ;; Casting to z, another RTT of the same data type, fails.
   (call $log
    (ref.test $extendedstruct
     (local.get $any)
-    (local.get $z)
+    (rtt.canon $extendedstruct)
    )
   )
   ;; Casting to x, the parent of y, works.
   (call $log
    (ref.test $struct
     (local.get $any)
-    (local.get $x)
+    (rtt.canon $struct)
    )
   )
  )