On Fri, Dec 10, 2021 at 05:36:20PM +0000, Kwok Cheung Yeung wrote:
> 2021-12-10 Kwok Cheung Yeung <k...@codesourcery.com>
>
> gcc/
> * Makefile.in (OBJS): Add omp-expand-metadirective.o.
> * gimple-streamer-in.c (input_gimple_stmt): Add case for
> GIMPLE_OMP_METADIRECTIVE. Handle metadirective labels.
> * gimple-streamer-out.c (output_gimple_stmt): Likewise.
> * omp-expand-metadirective.cc: New.
> * passes.def: Add pass_omp_expand_metadirective.
> * tree-pass.h (make_pass_omp_expand_metadirective): New prototype.
> ---
> gcc/Makefile.in | 1 +
> gcc/gimple-streamer-in.c | 10 ++
> gcc/gimple-streamer-out.c | 6 +
> gcc/omp-expand-metadirective.cc | 191 ++++++++++++++++++++++++++++++++
> gcc/passes.def | 1 +
> gcc/tree-pass.h | 1 +
> 6 files changed, 210 insertions(+)
> create mode 100644 gcc/omp-expand-metadirective.cc
>
> @@ -151,6 +151,7 @@ input_gimple_stmt (class lto_input_block *ib, class
> data_in *data_in,
> case GIMPLE_COND:
> case GIMPLE_GOTO:
> case GIMPLE_DEBUG:
> + case GIMPLE_OMP_METADIRECTIVE:
> for (i = 0; i < num_ops; i++)
> {
> tree *opp, op = stream_read_tree (ib, data_in);
> @@ -188,6 +189,15 @@ input_gimple_stmt (class lto_input_block *ib, class
> data_in *data_in,
> else
> gimple_call_set_fntype (call_stmt, stream_read_tree (ib, data_in));
> }
> + if (gomp_metadirective *metadirective_stmt
> + = dyn_cast <gomp_metadirective*> (stmt))
> + {
> + gimple_alloc_omp_metadirective (metadirective_stmt);
> + for (i = 0; i < num_ops; i++)
> + gimple_omp_metadirective_set_label (metadirective_stmt, i,
> + stream_read_tree (ib,
> + data_in));
> + }
Ah, sorry for the comment about LTO streaming, here it is.
> --- /dev/null
> +++ b/gcc/omp-expand-metadirective.cc
> @@ -0,0 +1,191 @@
> +/* Expand an OpenMP metadirective.
> +
> + Copyright (C) 2021 Free Software Foundation, Inc.
We have 2022 now...
> +
Missing function comment.
> +static void
> +omp_expand_metadirective (function *fun, basic_block bb)
> +{
> + gimple *stmt = last_stmt (bb);
> + vec<struct omp_metadirective_variant> candidates
> + = omp_resolve_metadirective (stmt);
> +
> + /* This is the last chance for the metadirective to be resolved. */
> + if (candidates.is_empty ())
> + gcc_unreachable ();
gcc_assert (!candidates.is_empty ());
?
> + /* opt_pass methods: */
> + virtual bool gate (function *)
> + {
> + return (flag_openmp);
Useless ()s around it.
But much more importantly, I don't really like this to be a separate pass,
walking the whole IL once more is expensive, even when you restrict it
to just flag_openmp.
Late declare variant resolving is done in the (now a little bit misnamed)
pass_omp_device_lower.
The gate of that pass is right now:
return (!(fun->curr_properties & PROP_gimple_lomp_dev)
|| (flag_openmp
&& cgraph_node::get (fun->decl)->calls_declare_variant_alt));
so it would be nice to track (conservatively)
whether current function has any metadirectives
in it which aren't yet resolved (but perhaps the calls_declare_variant_alt
bit could be abused for that too) andin that case also deal with those.
You can surely gather them in the omp-offload.cc pass and then call
a function in your new file to handle that.
Jakub
