On Thu, Oct 19, 2023 at 9:59 AM Alexandre Oliva <ol...@adacore.com> wrote:
>
>
> The need to initialize edge probabilities has made make_eh_edges
> undesirably hard to use. I suppose we don't want make_eh_edges to
> initialize the probability of the newly-added edge itself, so that the
> caller takes care of it, but identifying the added edge in need of
> adjustments is inefficient and cumbersome. Change make_eh_edges so
> that it returns the added edge.
>
> Regstrapped on x86_64-linux-gnu, and (along with various hardening
> patches) on ppc64el-linux-gnu. Also tested on multiple other targets,
> on older versions of GCC. The returned value is unused in code already
> in the compiler. This is a preparatory patch for uses to be introduced
> along with stack scrubbing and control flow redundancy. Ok to install?
OK. Maybe time to do s/make_eh_edges/make_eh_edge/ though.
Richard.
>
> for gcc/ChangeLog
>
> * tree-eh.cc (make_eh_edges): Return the new edge.
> * tree-eh.h (make_eh_edges): Likewise.
> ---
> gcc/tree-eh.cc | 6 +++---
> gcc/tree-eh.h | 2 +-
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/gcc/tree-eh.cc b/gcc/tree-eh.cc
> index e8ceff36cc6e7..1cb8e08652909 100644
> --- a/gcc/tree-eh.cc
> +++ b/gcc/tree-eh.cc
> @@ -2274,7 +2274,7 @@ make_eh_dispatch_edges (geh_dispatch *stmt)
> /* Create the single EH edge from STMT to its nearest landing pad,
> if there is such a landing pad within the current function. */
>
> -void
> +edge
> make_eh_edges (gimple *stmt)
> {
> basic_block src, dst;
> @@ -2283,14 +2283,14 @@ make_eh_edges (gimple *stmt)
>
> lp_nr = lookup_stmt_eh_lp (stmt);
> if (lp_nr <= 0)
> - return;
> + return NULL;
>
> lp = get_eh_landing_pad_from_number (lp_nr);
> gcc_assert (lp != NULL);
>
> src = gimple_bb (stmt);
> dst = label_to_block (cfun, lp->post_landing_pad);
> - make_edge (src, dst, EDGE_EH);
> + return make_edge (src, dst, EDGE_EH);
> }
>
> /* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree;
> diff --git a/gcc/tree-eh.h b/gcc/tree-eh.h
> index 771be50fe9a1d..1382568b7c919 100644
> --- a/gcc/tree-eh.h
> +++ b/gcc/tree-eh.h
> @@ -30,7 +30,7 @@ extern bool remove_stmt_from_eh_lp (gimple *);
> extern int lookup_stmt_eh_lp_fn (struct function *, const gimple *);
> extern int lookup_stmt_eh_lp (const gimple *);
> extern bool make_eh_dispatch_edges (geh_dispatch *);
> -extern void make_eh_edges (gimple *);
> +extern edge make_eh_edges (gimple *);
> extern edge redirect_eh_edge (edge, basic_block);
> extern void redirect_eh_dispatch_edge (geh_dispatch *, edge, basic_block);
> extern bool operation_could_trap_helper_p (enum tree_code, bool, bool, bool,
>
>
> --
> Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
> Free Software Activist GNU Toolchain Engineer
> More tolerance and less prejudice are key for inclusion and diversity
> Excluding neuro-others for not behaving ""normal"" is *not* inclusive
