On Sat, 5 Sep 2020, Jakub Jelinek wrote:
> Hi!
>
> The following patch adds streaming of edge goto_locus (both LOCATION_LOCUS
> and LOCATION_BLOCK from it), the PR shows a testcase (inappropriate for
> gcc testsuite) where the lack of streaming of goto_locus results in worse
> debug info.
> Earlier version of the patch (without the output_function changes) failed
> miserably, because on the order mismatch - input_function would
> first input_cfg, then input_eh_regions and then input_bb (all of which now
> have locations), while output_function used output_eh_regions, then output_bb
> and then output_cfg. *_cfg went to a separate stream...
> Now, is there a reason why the order is different?
It's probably simply an oversight.
> Bootstrap/regtest on x86_64-linux and i686-linux went fine after changing
> that,
> including lto bootstrap on x86_64-linux.
OK.
Thanks,
Richard.
> If the intent is that the cfg could be read separately from the rest of
> function or vice versa, alternatively we'd need to clear_line_info ();
> before output_eh_regions and before/after output_cfg to make them
> independent.
>
> 2020-09-05 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/94235
> * lto-streamer-out.c (output_cfg): Also stream goto_locus for edges.
> Use bp_pack_var_len_unsigned instead of streamer_write_uhwi to stream
> e->dest->index and e->flags.
> (output_function): Call output_cfg before output_ssa_name, rather than
> after streaming all bbs.
> * lto-streamer-in.c (input_cfg): Stream in goto_locus for edges.
> Use bp_unpack_var_len_unsigned instead of streamer_read_uhwi to stream
> in dest_index and edge_flags.
>
> --- gcc/lto-streamer-out.c.jj 2020-09-04 11:53:22.673647471 +0200
> +++ gcc/lto-streamer-out.c 2020-09-04 22:42:14.595657649 +0200
> @@ -2100,9 +2100,11 @@ output_cfg (struct output_block *ob, str
> streamer_write_uhwi (ob, EDGE_COUNT (bb->succs));
> FOR_EACH_EDGE (e, ei, bb->succs)
> {
> - streamer_write_uhwi (ob, e->dest->index);
> + bitpack_d bp = bitpack_create (ob->main_stream);
> + bp_pack_var_len_unsigned (&bp, e->dest->index);
> + bp_pack_var_len_unsigned (&bp, e->flags);
> + stream_output_location_and_block (ob, &bp, e->goto_locus);
> e->probability.stream_out (ob);
> - streamer_write_uhwi (ob, e->flags);
> }
> }
>
> @@ -2418,6 +2420,8 @@ output_function (struct cgraph_node *nod
> streamer_write_uhwi (ob, 1);
> output_struct_function_base (ob, fn);
>
> + output_cfg (ob, fn);
> +
> /* Output all the SSA names used in the function. */
> output_ssa_names (ob, fn);
>
> @@ -2430,8 +2434,6 @@ output_function (struct cgraph_node *nod
>
> /* The terminator for this function. */
> streamer_write_record_start (ob, LTO_null);
> -
> - output_cfg (ob, fn);
> }
> else
> streamer_write_uhwi (ob, 0);
> --- gcc/lto-streamer-in.c.jj 2020-09-04 11:55:08.069114502 +0200
> +++ gcc/lto-streamer-in.c 2020-09-04 13:26:04.439987053 +0200
> @@ -780,23 +780,19 @@ input_cfg (class lto_input_block *ib, cl
> /* Connect up the CFG. */
> for (i = 0; i < edge_count; i++)
> {
> - unsigned int dest_index;
> - unsigned int edge_flags;
> - basic_block dest;
> - profile_probability probability;
> - edge e;
> -
> - dest_index = streamer_read_uhwi (ib);
> - probability = profile_probability::stream_in (ib);
> - edge_flags = streamer_read_uhwi (ib);
> -
> - dest = BASIC_BLOCK_FOR_FN (fn, dest_index);
> + bitpack_d bp = streamer_read_bitpack (ib);
> + unsigned int dest_index = bp_unpack_var_len_unsigned (&bp);
> + unsigned int edge_flags = bp_unpack_var_len_unsigned (&bp);
> + basic_block dest = BASIC_BLOCK_FOR_FN (fn, dest_index);
>
> if (dest == NULL)
> dest = make_new_block (fn, dest_index);
>
> - e = make_edge (bb, dest, edge_flags);
> - e->probability = probability;
> + edge e = make_edge (bb, dest, edge_flags);
> + data_in->location_cache.input_location_and_block (&e->goto_locus,
> + &bp, ib, data_in);
> + e->probability = profile_probability::stream_in (ib);
> +
> }
>
> index = streamer_read_hwi (ib);
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
