On Tue, Feb 24, 2026 at 7:52 AM Alfie Richards <[email protected]> wrote:
>
> Hi All,
>
> This is a fix for the failures I introduced with my FMV series.
>
> Appologies for the regression in the first place. I was regression testing
> pretty thoroughly when working on that series so I am confused how this was
> never caught. As far as I can tell, the code as written would never have
> worked.
>
> Perhaps I got something wrong in a rebase.
>
> Either way, the fix seems pretty lightweight.
>
> Regression tested on aarch64-linux-gnu and x86_64-linux-gnu.
>
> Ok for master?
Ok but please add a testcase since there was a simple one in the bug report.
Thanks,
Andrew
>
> KR,
> Alfie
>
> -- >8 --
>
> Fix the reachability checks for FMV nodes which were put in the wrong
> place and fix the definition value for a dispatched symbol to match
> that of the default node.
>
> PR target/124167
>
> gcc/ChangeLog
>
> * attribs.cc (make_dispatcher_decl): Change node->definition
> to inherit from the node its called on.
> * ipa.cc (remote_unreachable_nodes): Move FMV logic out of
> (!in_boundary_p) if block.
> ---
> gcc/attribs.cc | 6 +++++-
> gcc/ipa.cc | 19 +++++++++----------
> 2 files changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/gcc/attribs.cc b/gcc/attribs.cc
> index c63d13d7e55..99f2fd75531 100644
> --- a/gcc/attribs.cc
> +++ b/gcc/attribs.cc
> @@ -1230,7 +1230,11 @@ make_dispatcher_decl (const tree decl)
> /* Set flags on the cgraph_node for the new decl. */
> cgraph_node *func_node = cgraph_node::get_create (func_decl);
> func_node->dispatcher_function = true;
> - func_node->definition = true;
> + /* For targets with TARGET_HAS_FMV_TARGET_ATTRIBUTE, the resolver is
> created
> + unconditionally if any versioned nodes are present.
> + For !TARGET_HAS_FMV_TARGET_ATTRIBUTE, the dispatcher is only defined
> when
> + the default node is defined. */
> + func_node->definition = node->definition ||
> TARGET_HAS_FMV_TARGET_ATTRIBUTE;
>
> cgraph_function_version_info *func_v
> = func_node->insert_new_function_version ();
> diff --git a/gcc/ipa.cc b/gcc/ipa.cc
> index ca939c9c118..d1a0bb8ce1d 100644
> --- a/gcc/ipa.cc
> +++ b/gcc/ipa.cc
> @@ -441,16 +441,6 @@ symbol_table::remove_unreachable_nodes (FILE *file)
> }
> }
>
> - /* A reference to the default node implies use of all the other
> - versions (they get used in the function resolver made later
> - in multiple_target.cc) */
> - cgraph_function_version_info *node_v = cnode->function_version
> ();
> - if (node_v && is_function_default_version (node->decl))
> - for (cgraph_function_version_info *fvi = node_v->next;
> - fvi;
> - fvi = fvi->next)
> - enqueue_node (fvi->this_node, &first, &reachable);
> -
> for (e = cnode->callees; e; e = e->next_callee)
> {
> symtab_node *body = e->callee->function_symbol ();
> @@ -494,6 +484,15 @@ symbol_table::remove_unreachable_nodes (FILE *file)
> else if (cnode->thunk)
> enqueue_node (cnode->callees->callee, &first, &reachable);
>
> + /* A reference to the default node implies use of all the other
> + versions (they get used in the function resolver made later
> + in multiple_target.cc) */
> + cgraph_function_version_info *node_v = cnode->function_version ();
> + if (node_v && is_function_default_version (node->decl))
> + for (cgraph_function_version_info *fvi = node_v->next; fvi;
> + fvi = fvi->next)
> + enqueue_node (fvi->this_node, &first, &reachable);
> +
> /* If any reachable function has simd clones, mark them as
> reachable as well. */
> if (cnode->simd_clones)
> --
> 2.34.1
>
