testsuite: Add test for #14768

(cherry picked from commit da468130)

testsuite/tests/simplCore/should_run/T14768.hs

+{-# LANGUAGE MagicHash             #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeFamilies          #-}
+
+module Main where
+
+import Control.Monad (forM_, liftM)
+import qualified Data.Vector.Generic         as G
+import qualified Data.Vector.Generic.Mutable as M
+import qualified Data.Vector.Primitive as P
+import qualified Data.Vector.Unboxed         as U
+import qualified Data.Vector.Unboxed.Mutable as MU
+import GHC.Exts
+
+vec :: U.Vector Moebius
+vec = U.singleton Moebius0
+
+main :: IO ()
+main = print $ U.head vec == U.head vec
+
+data Moebius = Moebius0 | Moebius1 | Moebius2
+  deriving (Eq)
+
+fromMoebius :: Moebius -> Int
+fromMoebius Moebius0 = 0
+fromMoebius Moebius1 = 1
+fromMoebius Moebius2 = 2
+
+toMoebius :: Int -> Moebius
+toMoebius (I# i#) = tagToEnum# i#
+
+newtype instance U.MVector s Moebius = MV_Moebius (P.MVector s Int)
+newtype instance U.Vector    Moebius = V_Moebius  (P.Vector    Int)
+
+instance U.Unbox Moebius
+
+instance M.MVector U.MVector Moebius where
+  basicLength (MV_Moebius v) = M.basicLength v
+  basicUnsafeSlice i n (MV_Moebius v) = MV_Moebius $ M.basicUnsafeSlice i n v
+  basicOverlaps (MV_Moebius v1) (MV_Moebius v2) = M.basicOverlaps v1 v2
+  basicUnsafeNew n = MV_Moebius `liftM` M.basicUnsafeNew n
+  basicInitialize (MV_Moebius v) = M.basicInitialize v
+  basicUnsafeReplicate n x = MV_Moebius `liftM` M.basicUnsafeReplicate n (fromMoebius x)
+  basicUnsafeRead (MV_Moebius v) i = toMoebius `liftM` M.basicUnsafeRead v i
+  basicUnsafeWrite (MV_Moebius v) i x = M.basicUnsafeWrite v i (fromMoebius x)
+  basicClear (MV_Moebius v) = M.basicClear v
+  basicSet (MV_Moebius v) x = M.basicSet v (fromMoebius x)
+  basicUnsafeCopy (MV_Moebius v1) (MV_Moebius v2) = M.basicUnsafeCopy v1 v2
+  basicUnsafeMove (MV_Moebius v1) (MV_Moebius v2) = M.basicUnsafeMove v1 v2
+  basicUnsafeGrow (MV_Moebius v) n = MV_Moebius `liftM` M.basicUnsafeGrow v n
+
+instance G.Vector U.Vector Moebius where
+  basicUnsafeFreeze (MV_Moebius v) = V_Moebius `liftM` G.basicUnsafeFreeze v
+  basicUnsafeThaw (V_Moebius v) = MV_Moebius `liftM` G.basicUnsafeThaw v
+  basicLength (V_Moebius v) = G.basicLength v
+  basicUnsafeSlice i n (V_Moebius v) = V_Moebius $ G.basicUnsafeSlice i n v
+  basicUnsafeIndexM (V_Moebius v) i = toMoebius `liftM` G.basicUnsafeIndexM v i
+  basicUnsafeCopy (MV_Moebius mv) (V_Moebius v) = G.basicUnsafeCopy mv v
+  elemseq _ = seq

testsuite/tests/simplCore/should_run/all.T

@@ -78,3 +78,4 @@ test('T13429', normal, compile_and_run, [''])
 test('T13429_2', normal, compile_and_run, [''])
 test('T13750', normal, compile_and_run, [''])
 test('T14178', normal, compile_and_run, [''])
+test('T14768', reqlib('vector'), compile_and_run, [''])