On Thu, Oct 14, 2021 at 9:00 AM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> rs6000_density_test has an early exit test between a call
> to get_loop_body and the corresponding free. This would
> lead to a memory leak if the early exit is taken.
>
> Tested on powerpc64le-linux-gnu. It's obvious that moving the
> test avoids the leak, but there are multiple ways to write it,
> so: OK to install?
Thanks for noticing this and creating a patch.
This is okay.
Thanks, David
>
> Richard
>
>
> gcc/
> * config/rs6000/rs6000.c (rs6000_density_test): Move early
> exit test further up the function.
> ---
> gcc/config/rs6000/rs6000.c | 17 ++++++++---------
> 1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index acba4d9f26c..01a95591a5d 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -5289,20 +5289,19 @@ struct rs6000_cost_data
> static void
> rs6000_density_test (rs6000_cost_data *data)
> {
> - struct loop *loop = data->loop_info;
> - basic_block *bbs = get_loop_body (loop);
> - int nbbs = loop->num_nodes;
> - loop_vec_info loop_vinfo = loop_vec_info_for_loop (data->loop_info);
> - int vec_cost = data->cost[vect_body], not_vec_cost = 0;
> - int i, density_pct;
> -
> /* This density test only cares about the cost of vector version of the
> loop, so immediately return if we are passed costing for the scalar
> version (namely computing single scalar iteration cost). */
> if (data->costing_for_scalar)
> return;
>
> - for (i = 0; i < nbbs; i++)
> + struct loop *loop = data->loop_info;
> + basic_block *bbs = get_loop_body (loop);
> + int nbbs = loop->num_nodes;
> + loop_vec_info loop_vinfo = loop_vec_info_for_loop (data->loop_info);
> + int vec_cost = data->cost[vect_body], not_vec_cost = 0;
> +
> + for (int i = 0; i < nbbs; i++)
> {
> basic_block bb = bbs[i];
> gimple_stmt_iterator gsi;
> @@ -5322,7 +5321,7 @@ rs6000_density_test (rs6000_cost_data *data)
> }
>
> free (bbs);
> - density_pct = (vec_cost * 100) / (vec_cost + not_vec_cost);
> + int density_pct = (vec_cost * 100) / (vec_cost + not_vec_cost);
>
> if (density_pct > rs6000_density_pct_threshold
> && vec_cost + not_vec_cost > rs6000_density_size_threshold)
