remove more Addr bits

[ghc-hetmet.git] / compiler / typecheck / TcSimplify.lhs

diff --git a/compiler/typecheck/TcSimplify.lhs b/compiler/typecheck/TcSimplify.lhs
index 19557c6..4cb32b8 100644 (file)
--- a/compiler/typecheck/TcSimplify.lhs
+++ b/compiler/typecheck/TcSimplify.lhs
@@ -42,8 +42,7 @@ import Inst           ( lookupInst, LookupInstResult(..),
 import TcEnv           ( tcGetGlobalTyVars, tcLookupId, findGlobals, pprBinders,
                          lclEnvElts, tcMetaTy )
 import InstEnv         ( lookupInstEnv, classInstances, pprInstances )
-import TcMType         ( zonkTcTyVarsAndFV, tcInstTyVars, zonkTcPredType,
-                         checkAmbiguity, checkInstTermination )
+import TcMType         ( zonkTcTyVarsAndFV, tcInstTyVars, zonkTcPredType  )
 import TcType          ( TcTyVar, TcTyVarSet, ThetaType, TcPredType, tidyPred,
                           mkClassPred, isOverloadedTy, mkTyConApp, isSkolemTyVar,
                          mkTyVarTy, tcGetTyVar, isTyVarClassPred, mkTyVarTys,
@@ -2283,19 +2282,10 @@ tcSimplifyDeriv tc tyvars theta
        rev_env = zipTopTvSubst tvs (mkTyVarTys tyvars)
                -- This reverse-mapping is a Royal Pain, 
                -- but the result should mention TyVars not TcTyVars
-
-       head_ty = TyConApp tc (map TyVarTy tvs)
     in
    
     addNoInstanceErrs Nothing [] bad_insts             `thenM_`
     mapM_ (addErrTc . badDerivedPred) weird_preds      `thenM_`
-    checkAmbiguity tvs simpl_theta tv_set              `thenM_`
-      -- Check instance termination as for user-declared instances.
-      -- unless we had -fallow-undecidable-instances (which risks
-      -- non-termination in the 'deriving' context-inference fixpoint
-      -- loop).
-    ifM (gla_exts && not undecidable_ok)
-       (checkInstTermination simpl_theta [head_ty])    `thenM_`
     returnM (substTheta rev_env simpl_theta)
   where
     doc    = ptext SLIT("deriving classes for a data type")