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[Bug lto/45375] [meta-bug] Issues with building Mozilla with LTO
- From: "hubicka at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 19 May 2011 22:43:23 +0000
- Subject: [Bug lto/45375] [meta-bug] Issues with building Mozilla with LTO
- Auto-submitted: auto-generated
- References: <bug-45375-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375
--- Comment #92 from Jan Hubicka <hubicka at gcc dot gnu.org> 2011-05-19 22:28:18 UTC ---
decl in is now at 96 seconds.
oprofile for streaming in is:
27469 9.3054 lto1 htab_find_slot_with_hash
23175 7.8508 libc-2.11.1.so _int_malloc
18044 6.1126 lto1 lto_input_tree
14823 5.0215 libc-2.11.1.so memset
14108 4.7792 lto1 gt_ggc_mx_lang_tree_node
13511 4.5770 lto1 inflate_fast
11805 3.9991 lto1 gimple_type_eq
11247 3.8100 lto1 lto_input_uleb128
11227 3.8033 lto1 ggc_set_mark
10903 3.6935 lto1 pointer_map_insert
So obviously still some place for improvements for merging. I think malloc
calls come mostly from SCC detection code (we create a lot of temporary
obstacks and pointer maps). lto_input_tree can probably handle quite a lot of
optimizations reducing amount of data we stream. Plus we don't really need to
stream ulebs for everything.
For whole WPA we now need about 5 minutes, the oprofile is:
152067 14.9073 lto1 decl_assembler_name_equal
48258 4.7308 lto1 htab_find_slot_with_hash
46730 4.5810 lto1 edge_badness
37954 3.7207 libc-2.11.1.so _int_malloc
36692 3.5970 lto1 pointer_map_insert
30387 2.9789 lto1 do_estimate_growth
28496 2.7935 lto1 lto_input_tree
20992 2.0579 lto1 inflate_fast
20765 2.0356 libc-2.11.1.so memset
20264 1.9865 lto1 varpool_node_for_asm
19784 1.9394 lto1 lto_output_tree
19121 1.8745 lto1 htab_hash_string
19053 1.8678 lto1 lto_input_uleb128
good news is that decl_assembler_name_equal is stupid handling of varpool
aliases in varpool_node_for_asm that will go away with my alias rewrite.
edge_badness is easy to track down, too, it is just inliner updating paranoia.
Honza