On Sat, May 31, 2025 at 11:07 AM Andrew Pinski <quic_apin...@quicinc.com> wrote:
>
> Right now the only place where CCP needs to have the virtual op renamed is
> after inserting clobbers which come right before __builtin_stack_restore.
> So let's manually do the correct thing so we can remove the TODO_update_ssa
> todo.
OK.
Thanks,
Richard.
> gcc/ChangeLog:
>
> * tree-ssa-ccp.cc (insert_clobber_before_stack_restore): Update the
> virtual
> op on the inserted clobber and the stack restore function.
> (do_ssa_ccp): Don't add TODO_update_ssa to the todo.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/tree-ssa-ccp.cc | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/tree-ssa-ccp.cc b/gcc/tree-ssa-ccp.cc
> index 8d2cbb384c4..6022ea446a4 100644
> --- a/gcc/tree-ssa-ccp.cc
> +++ b/gcc/tree-ssa-ccp.cc
> @@ -2567,7 +2567,12 @@ insert_clobber_before_stack_restore (tree saved_val,
> tree var,
> {
> clobber = build_clobber (TREE_TYPE (var), CLOBBER_STORAGE_END);
> clobber_stmt = gimple_build_assign (var, clobber);
> -
> + /* Manually update the vdef/vuse here. */
> + gimple_set_vuse (clobber_stmt, gimple_vuse (stmt));
> + gimple_set_vdef (clobber_stmt, make_ssa_name (gimple_vop (cfun)));
> + gimple_set_vuse (stmt, gimple_vdef (clobber_stmt));
> + SSA_NAME_DEF_STMT (gimple_vdef (clobber_stmt)) = clobber_stmt;
> + update_stmt (stmt);
> i = gsi_for_stmt (stmt);
> gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT);
> }
> @@ -3020,7 +3025,7 @@ do_ssa_ccp (bool nonzero_p)
> ccp_propagate.ssa_propagate ();
> if (ccp_finalize (nonzero_p || flag_ipa_bit_cp))
> {
> - todo = (TODO_cleanup_cfg | TODO_update_ssa);
> + todo = TODO_cleanup_cfg;
>
> /* ccp_finalize does not preserve loop-closed ssa. */
> loops_state_clear (LOOP_CLOSED_SSA);
> --
> 2.43.0
>
