1 files changed, 24 insertions, 3 deletions
diff --git a/byterun/alloc.c b/byterun/alloc.c
index 0a1c5499a..cc19698a8 100644
--- a/byterun/alloc.c
+++ b/byterun/alloc.c
@@ -153,13 +153,34 @@ CAMLprim value caml_alloc_dummy(value size)
   return caml_alloc (wosize, 0);
 }
 
+CAMLprim value caml_alloc_dummy_float (value size)
+{
+  mlsize_t wosize = Int_val(size) * Double_wosize;
+
+  if (wosize == 0) return Atom(0);
+  return caml_alloc (wosize, 0);
+}
+
 CAMLprim value caml_update_dummy(value dummy, value newval)
 {
   mlsize_t size, i;
+  tag_t tag;
+
   size = Wosize_val(newval);
+  tag = Tag_val (newval);
   Assert (size == Wosize_val(dummy));
-  Tag_val(dummy) = Tag_val(newval);
-  for (i = 0; i < size; i++)
-    caml_modify(&Field(dummy, i), Field(newval, i));
+  Assert (tag < No_scan_tag || tag == Double_array_tag);
+
+  Tag_val(dummy) = tag;
+  if (tag == Double_array_tag){
+    size = Wosize_val (newval) / Double_wosize;
+    for (i = 0; i < size; i++){
+      Store_double_field (dummy, i, Double_field (newval, i));
+    }
+  }else{
+    for (i = 0; i < size; i++){
+      caml_modify (&Field(dummy, i), Field(newval, i));
+    }
+  }
   return Val_unit;
 }