Lua backend: Eliminate table_unpackN(table_pack(...))

minoki · Sep 12, 2024 · 07a42ac · 07a42ac
1 parent 9b0b0fc
commit 07a42ac
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/codegen-lua.sml b/src/codegen-lua.sml
@@ -218,6 +218,9 @@ struct
           , L.ConstExp (L.Numeral "1")
           , L.IndexExp (x, L.ConstExp (L.LiteralString "n"))
           ])
+    | TableUnpackN (x as L.CallExp (L.VarExp (L.PredefinedId "table_pack"), a)) =
+        if Vector.length a = 1 then Vector.sub (a, 0)
+        else L.CallExp (L.VarExp (L.PredefinedId "table_unpackN"), vector [x])
     | TableUnpackN x =
         L.CallExp (L.VarExp (L.PredefinedId "table_unpackN"), vector [x])