Simon Jakobi pushed to branch wip/sjakobi/checkTyEqRhs at Glasgow Haskell Compiler / GHC

Commits:

• 5068e09e
  by Simon Jakobi at 2026-05-25T12:46:06+02:00

  Prevent dictionary-passing in checkTyEqRhs
  
  ...by pre-specializing it to TcM.
  
  Previously, wherever checkTyEqRhs was used in other modules, the
  Core showed dictionary passing ($fMonadIOEnv). The added SPECIALIZE
  pragma prevents this.
  

1 changed file:

• compiler/GHC/Tc/Utils/Unify.hs

Changes:

   = recurseIntoFamTyConApp flags tc tys

   | otherwise

   = check_ty_eq_rhs flags rhs

+-- Prevent dictionary-passing when checkTyEqRhs is used in TcM in other modules:

+{-# SPECIALIZE checkTyEqRhs :: TyEqFlags TcM a -> TcType -> TcM (PuResult a Reduction) #-}

 {- Note [Special case for top-level of Given equality]

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