diff options
| -rw-r--r-- | compiler/specialise/SpecConstr.lhs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/compiler/specialise/SpecConstr.lhs b/compiler/specialise/SpecConstr.lhs index cbe1c0b76a..0b61a57c0d 100644 --- a/compiler/specialise/SpecConstr.lhs +++ b/compiler/specialise/SpecConstr.lhs @@ -1549,6 +1549,9 @@ argToPat env in_scope val_env (Case scrut _ _ [(_, _, rhs)]) arg_occ -} argToPat env in_scope val_env (Cast arg co) arg_occ + | isIdentityCoercion co -- Substitution in the SpecConstr itself + -- can lead to identity coercions + = argToPat env in_scope val_env arg arg_occ | not (ignoreType env ty2) = do { (interesting, arg') <- argToPat env in_scope val_env arg arg_occ ; if not interesting then |