On Wed, Sep 4, 2024 at 1:58 AM Andrew Pinski <quic_apin...@quicinc.com> wrote:
>
> While trying to see if there was a way to improve object-size pass
> to use the ranger (for pointer plus), I noticed that it leaves around
> the statement containing __builtin_object_size if it was reduced to a
> constant.
> This fixes that by using simple_dce_from_worklist.
>
> Bootstrapped and tested on x86_64-linux-gnu.
OK.
> gcc/ChangeLog:
>
> * tree-object-size.cc (object_sizes_execute): Mark lhs for maybe
> dceing
> if doing a propagate. Call simple_dce_from_worklist.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/tree-object-size.cc | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
> index 4c1fa9b555f..6544730e153 100644
> --- a/gcc/tree-object-size.cc
> +++ b/gcc/tree-object-size.cc
> @@ -38,6 +38,7 @@ along with GCC; see the file COPYING3. If not see
> #include "builtins.h"
> #include "gimplify-me.h"
> #include "gimplify.h"
> +#include "tree-ssa-dce.h"
>
> struct object_size_info
> {
> @@ -2187,6 +2188,7 @@ static unsigned int
> object_sizes_execute (function *fun, bool early)
> {
> todo = 0;
> + auto_bitmap sdce_worklist;
>
> basic_block bb;
> FOR_EACH_BB_FN (bb, fun)
> @@ -2277,13 +2279,18 @@ object_sizes_execute (function *fun, bool early)
>
> /* Propagate into all uses and fold those stmts. */
> if (!SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> - replace_uses_by (lhs, result);
> + {
> + replace_uses_by (lhs, result);
> + /* Mark lhs as being possiblely DCEd. */
> + bitmap_set_bit (sdce_worklist, SSA_NAME_VERSION (lhs));
> + }
> else
> replace_call_with_value (&i, result);
> }
> }
>
> fini_object_sizes ();
> + simple_dce_from_worklist (sdce_worklist);
> return todo;
> }
>
> --
> 2.43.0
>
