On Mon, Sep 21 2026, Josef Melcr wrote:
> This patch adds a few shorthand functions to make further work with the
> new callback edges a little easier. They are pretty self explanatory.
> Some of them actaully contain some logic, but some of them exist just to
> make some if statements a little shorter.
>
> gcc/ChangeLog:
>
> * callback-info.cc (callback_call_arg_summary): Add
> implementation.
> (callback_call_num_args_summary): Likewise.
> (callback_ifn_assume_call_p): Likewise.
> (callback_ifn_assume_call_with_edge_p): Likewise.
> * callback-info.h (callback_call_arg_summary): New function,
> remaps arguments for callback calls.
> (callback_call_num_args_summary): New function, returns the
> correct number of arguments for callback calls.
> (callback_ifn_assume_call_p): New function, returns TRUE if the
> passed call is a call to IFN_ASSUME.
> (callback_ifn_assume_call_with_edge_p): New function, returns
> TRUE if the passed call is a call to IFN_ASSUME with an attached
> cgraph_edge.
>
> Signed-off-by: Josef Melcr <[email protected]>
> ---
> gcc/callback-info.cc | 54 ++++++++++++++++++++++++++++++++++++++++++++
> gcc/callback-info.h | 16 +++++++++++++
> 2 files changed, 70 insertions(+)
>
> diff --git a/gcc/callback-info.cc b/gcc/callback-info.cc
> index ec2291f3338..95357b9c8ff 100644
> --- a/gcc/callback-info.cc
> +++ b/gcc/callback-info.cc
> @@ -147,3 +147,57 @@ callback_info_sum_t::duplicate (cgraph_edge *,
> cgraph_edge *,
> dst_s->inverted_mapping = src_s->inverted_mapping.copy ();
> dst_s->redirected = src_s->redirected;
> }
> +
> +/* Return the argument at IDX if CI is null, otherwise use the mapping in CI
> and
Return the argument of STMT at IDX...
> + return the remapped argument. Presumes that the remapped index is not
> + ARG_MAPPING_UNKNOWN_IDX. */
> +tree
> +callback_call_arg_summary (gimple *stmt, int idx, callback_info *ci)
Please make stmt const gcall * (if easily possible).
> +{
> + if (ci)
> + idx = ci->arg_mapping[idx];
> + gcc_checking_assert (idx != ARG_MAPPING_UNKNOWN_IDX);
> + return gimple_call_arg (stmt, idx);
> +}
> +
> +/* Return the number of arguments of STMT if CI is null,
> + ci->arg_mapping.length() otherwise. */
> +unsigned
> +callback_call_num_args_summary (const gcall *stmt, callback_info *ci)
> +{
> + if (ci)
> + return ci->arg_mapping.length ();
> + return gimple_call_num_args (stmt);
> +}
> +
> +/* Returns TRUE iff STMT is an internal call statement to IFN_ASSUME. */
> +bool
> +callback_ifn_assume_call_p (gimple *stmt)
> +{
> + return is_gimple_call (stmt) && gimple_call_internal_p (stmt)
> + && (gimple_call_internal_fn (stmt) == IFN_ASSUME);
> +}
> +
> +/* Returns TRUE iff STMT is an internal call statement to IFN_ASSUME with a
> + callback edge to pointing to the outlined body. */
Extraneous "to."
But that is not all the function does, which I'm afraid requires some
explanation.
> +bool
> +callback_ifn_assume_call_with_edge_p (gimple *stmt)
> +{
> + /* Fast path for most cases. */
> + if (!callback_ifn_assume_call_p (stmt))
> + return false;
> +
> + tree decl = TREE_OPERAND (gimple_call_arg (stmt, 0), 0);
> + cgraph_node *node = cgraph_node::get (decl);
> + gcc_checking_assert (node->assume_function);
> +
> + if (!node->callers)
> + return false;
> +
Does this check catch the case where we have not created a callback edge
for whatever reason?
> + cgraph_edge *e;
> + for (e = node->callers; e; e = e->next_caller)
> + if (!e->callback)
> + return false;
... if there is a non-callback caller, is that because an assume
outlined function got ICFed together with a regular function or what is
this guarding against?
Please explain in the function comment what are all the criteria the
outlined function must meet for this function to return true.
Otherwise the patch is otherwise OK once patches using these functions
are approved.
Thanks,
Martin
