+atomPrimRep :: AnnExpr' Id ann -> PrimRep
+atomPrimRep (AnnVar v) = typePrimRep (idType v)
+atomPrimRep (AnnLit l) = typePrimRep (literalType l)
+atomPrimRep (AnnNote _ b) = atomPrimRep (snd b)
+atomPrimRep (AnnApp f (_, AnnType _)) = atomPrimRep (snd f)
+atomPrimRep (AnnLam x e) | isTyVar x = atomPrimRep (snd e)
+atomPrimRep (AnnCast b _) = atomPrimRep (snd b)
+atomPrimRep other = pprPanic "atomPrimRep" (ppr (deAnnotate (undefined,other)))
+