On Mon, 25 May 2020, Jan Hubicka wrote:
> Hi,
> as discussed on IRC this adds knob to disable stuff we stream "just for fun"
> (or to make it easier to debug streamer desychnonization).
>
> Te size of .o files in gcc subdirectory is reduced form 506MB to 492MB
>
> Bootstrapped/regtested x86_64-linux, OK?
OK.
> gcc/ChangeLog:
>
> 2020-05-25 Jan Hubicka <hubi...@ucw.cz>
>
> * lto-streamer-out.c (lto_output_tree): Add streamer_debugging check.
> * lto-streamer.h (streamer_debugging): New constant
> * tree-streamer-in.c (streamer_read_tree_bitfields): Add
> * streamer_debugging check.
> (streamer_get_pickled_tree): Likewise.
> * tree-streamer-out.c (pack_ts_base_value_fields): Likewise.
>
> diff --git a/gcc/lto-streamer-out.c b/gcc/lto-streamer-out.c
> index 887a51d3eae..288e3c0f4c6 100644
> --- a/gcc/lto-streamer-out.c
> +++ b/gcc/lto-streamer-out.c
> @@ -1748,8 +1748,9 @@ lto_output_tree (struct output_block *ob, tree expr,
> will instantiate two different nodes for the same object. */
> streamer_write_record_start (ob, LTO_tree_pickle_reference);
> streamer_write_uhwi (ob, ix);
> - streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS,
> - lto_tree_code_to_tag (TREE_CODE (expr)));
> + if (streamer_debugging)
> + streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS,
> + lto_tree_code_to_tag (TREE_CODE (expr)));
> lto_stats.num_pickle_refs_output++;
> }
> else
> diff --git a/gcc/lto-streamer.h b/gcc/lto-streamer.h
> index a466fb8b329..fbf1dd7162e 100644
> --- a/gcc/lto-streamer.h
> +++ b/gcc/lto-streamer.h
> @@ -125,6 +125,9 @@ along with GCC; see the file COPYING3. If not see
>
> typedef unsigned char lto_decl_flags_t;
>
> +/* Stream additional data to LTO object files to make it easier to debug
> + streaming code. This changes object files. */
> +static const bool streamer_debugging = false;
>
> /* Tags representing the various IL objects written to the bytecode file
> (GIMPLE statements, basic blocks, EH regions, tree nodes, etc).
> diff --git a/gcc/tree-streamer-in.c b/gcc/tree-streamer-in.c
> index 450f40d58d3..d2e45e33554 100644
> --- a/gcc/tree-streamer-in.c
> +++ b/gcc/tree-streamer-in.c
> @@ -487,9 +487,13 @@ streamer_read_tree_bitfields (class lto_input_block *ib,
>
> /* The first word in BP contains the code of the tree that we
> are about to read. */
> - code = (enum tree_code) bp_unpack_value (&bp, 16);
> - lto_tag_check (lto_tree_code_to_tag (code),
> - lto_tree_code_to_tag (TREE_CODE (expr)));
> + if (streamer_debugging)
> + {
> + code = (enum tree_code) bp_unpack_value (&bp, 16);
> + lto_tag_check (lto_tree_code_to_tag (code),
> + lto_tree_code_to_tag (TREE_CODE (expr)));
> + }
> + code = TREE_CODE (expr);
>
> /* Note that all these functions are highly sensitive to changes in
> the types and sizes of each of the fields being packed. */
> @@ -1107,11 +1111,14 @@ streamer_get_pickled_tree (class lto_input_block *ib,
> class data_in *data_in)
> enum LTO_tags expected_tag;
>
> ix = streamer_read_uhwi (ib);
> - expected_tag = streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
> -
> result = streamer_tree_cache_get_tree (data_in->reader_cache, ix);
> - gcc_assert (result
> - && TREE_CODE (result) == lto_tag_to_tree_code (expected_tag));
> +
> + if (streamer_debugging)
> + {
> + expected_tag = streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
> + gcc_assert (result
> + && TREE_CODE (result) == lto_tag_to_tree_code (expected_tag));
> + }
>
> return result;
> }
> diff --git a/gcc/tree-streamer-out.c b/gcc/tree-streamer-out.c
> index 4e8a12c71e6..94635c4a8ae 100644
> --- a/gcc/tree-streamer-out.c
> +++ b/gcc/tree-streamer-out.c
> @@ -71,7 +71,8 @@ write_identifier (struct output_block *ob,
> static inline void
> pack_ts_base_value_fields (struct bitpack_d *bp, tree expr)
> {
> - bp_pack_value (bp, TREE_CODE (expr), 16);
> + if (streamer_debugging)
> + bp_pack_value (bp, TREE_CODE (expr), 16);
> if (!TYPE_P (expr))
> {
> bp_pack_value (bp, TREE_SIDE_EFFECTS (expr), 1);
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
