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Currently the GivenCheck and GivenCheckSwap tests fail in the hpc way. GivenCheck is supposed to verify that a simple program with unreachable code throws an unreachable code warning:

type family S x

f :: a -> S a
f = undefined

g :: S a ~ Char => a -> Char
g y   | False           = f y
      | otherwise       = 'a'

In the normal way the case of g produces the following pre-optimised Core (-ddump-ds-preopt):

        case GHC.Types.False of wild_00 {
          False -> fail_dKd GHC.Prim.void#;
          True ->
            (f @a_aHn y_auo) `cast` (Sub co_aI6 :: S a_aHn[sk:1] ~R# Char)
        }
      }

However, in the hpc way it produces:

        case hpc<GivenCheckSwapMain,4>
             case GHC.Types.False of t1_dKd {
               False -> hpc<GivenCheckSwapMain,3> GHC.Types.False;
               True -> hpc<GivenCheckSwapMain,2> GHC.Types.True
             }
        of wild_00 {
          False -> fail_dKg GHC.Prim.void#;
          True ->
            hpc<GivenCheckSwapMain,6>
            (f @a_aHn (hpc<GivenCheckSwapMain,5> y_auo))
            `cast` (Sub co_aI6 :: S a_aHn[sk:1] ~R# Char)
        }

This is enough to hide the fact that the case is unreachable from the pattern match checker.