[Bug lto/45375] [meta-bug] Issues with building Mozilla with LTO

["hubicka at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375

--- Comment #142 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-10-08 22:19:55 UTC ---
After updating Mozilla this weekend, I definitely bloat up 8GB machine. The pak
in TOP is around 9-10GB.  I checked malloc usage and there are not many
surprises. It is about 300MB, mostly GGC overhead, pointer maps and such.

Most memory is actually the GGC, about 7GB. Here 5GB survives type and decl
merging and is distributed as follows:
cgraph.c:722 (cgraph_allocate_init_indirect_info    1671240: 0.0%          0:
0.0%    8202960: 0.2%          0: 0.0%     246855
tree.c:1226 (build_int_cst_wide)                  625825208:12.3%          0:
0.0%   10437744: 0.2%    4863752: 3.1%     325009
ipa-prop.h:471 (ipa_check_create_edge_args)               0: 0.0%          0:
0.0%   16777216: 0.3%          0: 0.0%          1
ipa-inline-analysis.c:3697 (inline_read_section)          0: 0.0%   28298904:
1.6%   21095504: 0.4%    1064480: 0.7%     423701
tree.c:1561 (build_string)                         16526800: 0.3%          0:
0.0%   21695715: 0.4%    3395427: 2.2%     864326
ipa-prop.c:3393 (ipa_read_node_info)                      0: 0.0%    4302088:
0.2%   25029448: 0.5%     119192: 0.1%     246788
stringpool.c:75 (alloc_node)                              0: 0.0%          0:
0.0%   27817760: 0.5%          0: 0.0%     695444
ipa-ref.c:51 (ipa_record_reference)                       0: 0.0% 
188442816:10.3%   28443272: 0.6%    2114424: 1.4%    1256259
stringpool.c:58 (stringpool_ggc_alloc)                    0: 0.0%          0:
0.0%   34673092: 0.7%    2619412: 1.7%     695444
lto/lto.c:2279 (create_subid_section_table)          275832: 0.0%          0:
0.0%   40363416: 0.8%    8051472: 5.2%       3978
tree-streamer-in.c:895 (lto_input_ts_constructor  171812232: 3.4% 
192568640:10.6%   42205992: 0.8%    1425072: 0.9%     947082
ipa-prop.c:3380 (ipa_read_node_info)                      0: 0.0%   35825488:
2.0%   58764528: 1.1%     659704: 0.4%     909232
tree-streamer-in.c:488 (streamer_alloc_tree)      129846168: 2.6%          0:
0.0%   75997752: 1.5%       7072: 0.0%    2063753
tree.c:1263 (build_int_cst_wide)                  237791264: 4.7%          0:
0.0%   90464320: 1.8%          0: 0.0%   10257987
ipa-inline-analysis.c:3709 (inline_read_section)          0: 0.0%  133938484:
7.4%  101874268: 2.0%    1606480: 1.0%    1099389
lto-section-in.c:361 (lto_new_in_decl_state)           3240: 0.0%          0:
0.0%  107452560: 2.1%          0: 0.0%     895465
cgraph.c:653 (cgraph_create_edge_1)                       0: 0.0%          0:
0.0%  135509816: 2.6%          0: 0.0%    1302979
ggc-common.c:253 (ggc_cleared_alloc_ptr_array_tw       2040: 0.0% 
866397160:47.6%  190623368: 3.7%     263888: 0.2%      11459
lto/lto.c:267 (lto_read_in_decl_state)                 3024: 0.0%          0:
0.0%  225743280: 4.4%   41057176:26.5%    6268255
ipa-inline-analysis.c:931 (inline_summary_alloc)          0: 0.0%          0:
0.0%  268435464: 5.2%          8: 0.0%          1
cgraph.c:362 (cgraph_allocate_node)                       0: 0.0%          0:
0.0%  515473640:10.1%          0: 0.0%    1741465
toplev.c:953 (realloc_for_line_map)                       0: 0.0% 
358955168:19.7% 1074790424:21.0%        184: 0.0%         19
tree-streamer-in.c:499 (streamer_alloc_tree)     3668091656:72.1%          0:
0.0% 1995384408:38.9%   87485792:56.5%   46580224
Total                                            5089831352       1821058652   
   5124870115        154815271         91384962
source location                                     Garbage            Freed   
         Leak         Overhead            Times

I.e. 20% are now linemaps, 38% trees read by the streamer, 10% cgraph nodes, 5%
inline summaries, 4% streamer table converting UIDs to decls (that can be
freed).

The trees are distributed as follows:
Kind                   Nodes      Bytes
---------------------------------------
decls                20489087 -1105370640
types                10321297 1733977896
blocks                102012    8160960
stmts                      0          0
refs                   44297    1806000
exprs                8205133  264995952
constants            11667038  376994197
identifiers           695444   27817760
vecs                  325009  626535448
binfos               2063753  205829776
ssa names                  0          0
constructors          369886    8877264
random kinds         7039351  281574472
lang_decl kinds            0          0
lang_type kinds            0          0
omp clauses                0          0
---------------------------------------
Total                61322307 -1863768211
---------------------------------------
Code                   Nodes

I think all the blocks read to WPA are bugs.  We may also do better on sharing
constants.
----------------------------
identifier_node       695444
tree_list            7039346
tree_vec              325009
block                 102012
offset_type             1762
enumeral_type         371554
boolean_type            7097
integer_type          830019
real_type              10054
pointer_type         3089539
reference_type        215629
array_type            204968
record_type          3818337
union_type             77106
void_type               1478
function_type         259759
method_type          1433688
integer_cst          10784917
real_cst               17553
string_cst            864326
function_decl        2736272
label_decl             82077
field_decl           3121989
var_decl              323843
const_decl           2817588
parm_decl            5244428
type_decl            4906573
result_decl          1225435
constructor           369886
pointer_plus_expr     302600
nop_expr             3307128
addr_expr            4592681
tree_binfo           2063753

Honza