From 42fcc7503af42314369e84e9a2cecc04deef0aad Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Tue, 11 Jul 2023 13:29:55 +0200 Subject: [PATCH] ada: Fix memory explosion on aggregate of nested packed array type It occurs at compile time on an aggregate of a 2-dimensional packed array type whose component type is itself a packed array, because the compiler is trying to pack the intermediate aggregate and ends up rewriting a bunch of subcomponents. This optimization was originally devised for the case of a scalar component type so the change adds this restriction. gcc/ada/ * exp_aggr.adb (Is_Two_Dim_Packed_Array): Return true only if the component type of the array is scalar. --- gcc/ada/exp_aggr.adb | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/gcc/ada/exp_aggr.adb b/gcc/ada/exp_aggr.adb index dffc5ab721db..cd5cc0b76698 100644 --- a/gcc/ada/exp_aggr.adb +++ b/gcc/ada/exp_aggr.adb @@ -306,7 +306,7 @@ package body Exp_Aggr is -- N is the N_Aggregate node to be expanded. function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean; - -- For two-dimensional packed aggregates with constant bounds and constant + -- For 2D packed array aggregates with constant bounds and constant scalar -- components, it is preferable to pack the inner aggregates because the -- whole matrix can then be presented to the back-end as a one-dimensional -- list of literals. This is much more efficient than expanding into single @@ -8563,9 +8563,11 @@ package body Exp_Aggr is function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean is C : constant Uint := Component_Size (Typ); + begin return Number_Dimensions (Typ) = 2 and then Is_Bit_Packed_Array (Typ) + and then Is_Scalar_Type (Component_Type (Typ)) and then C in Uint_1 | Uint_2 | Uint_4; -- False if No_Uint end Is_Two_Dim_Packed_Array; -- 2.47.2