Simon Peyton Jones pushed to branch wip/T27737 at Glasgow Haskell Compiler / GHC Commits: 8977eb41 by Simon Peyton Jones at 2026-10-02T16:44:38+01:00 Fix perf hole in exprIsConApp_maybe in subst_bndr. ToDo: document - - - - - 1 changed file: - compiler/GHC/Core/SimpleOpt.hs Changes: ===================================== compiler/GHC/Core/SimpleOpt.hs ===================================== @@ -1554,7 +1554,8 @@ exprIsConApp_maybe :: HasDebugCallStack => InScopeEnv -> CoreExpr -> Maybe (InScopeSet, FloatBinds, DataCon, [Type], [CoreExpr]) exprIsConApp_maybe ise@(ISE in_scope id_unf) expr - = go (Left in_scope) emptyFloatBinds expr (CC [] MRefl) + = -- pprTrace "exprIsConApp" (ppr expr) $ + go (Left in_scope) emptyFloatBinds expr (CC [] MRefl) where go :: Either InScopeSet Subst -- Left in-scope means "empty substitution" @@ -1667,7 +1668,8 @@ exprIsConApp_maybe ise@(ISE in_scope id_unf) expr | idArity fun == 0 , Just rhs <- expandUnfolding_maybe unfolding , let in_scope' = extend_in_scope (exprFreeVars rhs) - = go (Left in_scope') floats rhs cont + = -- pprTrace "exprIsConApp:unf" (ppr fun <+> ppr rhs) $ + go (Left in_scope') floats rhs cont -- See Note [exprIsConApp_maybe on literal strings] | (fun `hasKey` unpackCStringIdKey) || @@ -1707,17 +1709,21 @@ exprIsConApp_maybe ise@(ISE in_scope id_unf) expr subst_co (Right s) co = GHC.Core.Subst.substCo s co subst_expr (Left {}) e = e - subst_expr (Right s) e = substExpr s e + subst_expr (Right s) e = -- pprTrace "subst_expr" (text "subst" <+> ppr s $$ text "expr" <+> ppr e) $ + substExpr s e - subst_bndr msubst bndr - = (Right subst', bndr') + subst_bndrs subst bs = mapAccumL subst_bndr subst bs + + subst_bndr (Left in_scope) bndr + | bndr `elemInScopeSet` in_scope = subst_bndr1 (mkEmptySubst in_scope) bndr + | otherwise = (Left in_scope, bndr) + subst_bndr (Right subst) bndr = subst_bndr1 subst bndr + + subst_bndr1 subst bndr + = -- pprTrace "subst_bndr1" (ppr bndr <+> ppr bndr' $$ ppr subst) $ + (Right subst', bndr') where (subst', bndr') = substBndr subst bndr - subst = case msubst of - Left in_scope -> mkEmptySubst in_scope - Right subst -> subst - - subst_bndrs subst bs = mapAccumL subst_bndr subst bs extend (Left in_scope) v e = Right (extendSubst (mkEmptySubst in_scope) v e) extend (Right s) v e = Right (extendSubst s v e) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/8977eb4155aca08122ab1c8fad019b1d... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/8977eb4155aca08122ab1c8fad019b1d... You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help