diff options
Diffstat (limited to 'compiler/GHC/Core/SimpleOpt.hs')
| -rw-r--r-- | compiler/GHC/Core/SimpleOpt.hs | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/compiler/GHC/Core/SimpleOpt.hs b/compiler/GHC/Core/SimpleOpt.hs index bf9602bdaf..81bbc9247e 100644 --- a/compiler/GHC/Core/SimpleOpt.hs +++ b/compiler/GHC/Core/SimpleOpt.hs @@ -333,10 +333,21 @@ simple_app env (Var v) as simple_app env (App e1 e2) as = simple_app env e1 ((env, e2) : as) -simple_app env (Lam b e) (a:as) - = wrapLet mb_pr (simple_app env' e as) +simple_app env e@(Lam {}) as@(_:_) + | (bndrs, body) <- collectBinders e + , let zapped_bndrs = zapLamBndrs (length as) bndrs + -- Be careful to zap the lambda binders if necessary + -- c.f. the Lam caes of simplExprF1 in GHC.Core.Opt.Simplify + -- Lacking this zap caused #19347, when we had a redex + -- (\ a b. K a b) e1 e2 + -- where (as it happens) the eta-expanded K is produced by + -- Note [Linear fields generalization] in GHC.Tc.Gen.Head + = do_beta env zapped_bndrs body as where - (env', mb_pr) = simple_bind_pair env b Nothing a NotTopLevel + do_beta env (b:bs) body (a:as) + | (env', mb_pr) <- simple_bind_pair env b Nothing a NotTopLevel + = wrapLet mb_pr $ do_beta env' bs body as + do_beta env bs body as = simple_app env (mkLams bs body) as simple_app env (Tick t e) as -- Okay to do "(Tick t e) x ==> Tick t (e x)"? |