http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375
--- Comment #97 from Jan Hubicka <hubicka at gcc dot gnu.org> 2011-06-02
13:28:28 UTC ---
Today I noticed by an accident that the following hack:
Index: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c (revision 174547)
+++ lto-streamer-out.c (working copy)
@@ -1135,15 +1288,15 @@
lto_output_tree_or_ref (ob, BINFO_OFFSET (expr), ref_p);
lto_output_tree_or_ref (ob, BINFO_VTABLE (expr), ref_p);
- lto_output_tree_or_ref (ob, BINFO_VIRTUALS (expr), ref_p);
+ /*lto_output_tree_or_ref (ob, BINFO_VIRTUALS (expr), ref_p);*/
lto_output_tree_or_ref (ob, BINFO_VPTR_FIELD (expr), ref_p);
output_uleb128 (ob, VEC_length (tree, BINFO_BASE_ACCESSES (expr)));
FOR_EACH_VEC_ELT (tree, BINFO_BASE_ACCESSES (expr), i, t)
lto_output_tree_or_ref (ob, t, ref_p);
- lto_output_tree_or_ref (ob, BINFO_INHERITANCE_CHAIN (expr), ref_p);
- lto_output_tree_or_ref (ob, BINFO_SUBVTT_INDEX (expr), ref_p);
+ /* Backend do not care about BINFO_INHERITANCE_CHAIN and BINFO_SUBVTT_INDEX.
+ */
lto_output_tree_or_ref (ob, BINFO_VPTR_INDEX (expr), ref_p);
}
@@ -2014,7 +2167,7 @@
lto_output_tree_ref (ob, t);
/* Output the head of the arguments list. */
- lto_output_tree_ref (ob, DECL_ARGUMENTS (function));
+ lto_output_chain (ob, DECL_ARGUMENTS (function), true);
/* Output all the SSA names used in the function. */
output_ssa_names (ob, fn);
Index: lto-streamer-in.c
===================================================================
--- lto-streamer-in.c (revision 174547)
+++ lto-streamer-in.c (working copy)
@@ -2308,7 +2438,7 @@
while (t);
BINFO_OFFSET (expr) = lto_input_tree (ib, data_in);
- BINFO_VTABLE (expr) = lto_input_tree (ib, data_in);
+ /*BINFO_VTABLE (expr) = lto_input_tree (ib, data_in);*/
BINFO_VIRTUALS (expr) = lto_input_tree (ib, data_in);
BINFO_VPTR_FIELD (expr) = lto_input_tree (ib, data_in);
@@ -2323,8 +2453,6 @@
}
}
- BINFO_INHERITANCE_CHAIN (expr) = lto_input_tree (ib, data_in);
- BINFO_SUBVTT_INDEX (expr) = lto_input_tree (ib, data_in);
BINFO_VPTR_INDEX (expr) = lto_input_tree (ib, data_in);
}
Reduces memory usage from 4.4GB to 2.7GB, so almost halves it and
proportionally improves compilation speed. The effect is disabling type based
devirtualization.
The difference is amount of IL sreamed. W/o hack
> [WPA] Compression: 430817772 input bytes, 2004640654 uncompressed bytes
> (ratio: 4.653106)
> [WPA] Size of mmap'd section decls: 267817970 bytes
> [WPA] Size of mmap'd section function_body: 144808174 bytes
> ipa lto decl in : 74.90 (30%) usr 2.38 (19%) sys 77.51 (29%) wall
> 722892 kB (44%) ggc
(ggc memory info wraps around 4GB limit, have patch for that)
With hack:
> [WPA] Compression: 308616744 input bytes, 1236371760 uncompressed bytes
> (ratio: 4.006172)
> [WPA] Size of mmap'd section decls: 147396203 bytes
> [WPA] Size of mmap'd section function_body: 144662716 bytes
> ipa lto decl in : 38.85 (23%) usr 1.18 (12%) sys 40.12 (23%) wall
> 2674626 kB (75%) ggc
The node stats with the patch are as follows:
identifier_node 505095
tree_list 1809449
integer_type 175310
pointer_type 1198885
reference_type 65356
array_type 96153
record_type 729335
union_type 14171
function_type 120632
method_type 504881
integer_cst 587216
string_cst 204367
function_decl 909919
label_decl 261908
field_decl 1278114
var_decl 87787
const_decl 327835
parm_decl 1653719
type_decl 771617
result_decl 559971
debug_expr_decl 147434
constructor 162322
nop_expr 531950
addr_expr 920865
tree_binfo 1013612
(to be compared with my previous stats)
Heap vector stats:
ipa-prop.c:2053 (ipa_node_duplication_hook) 540408: 0.8% 1046048
21339: 0.2%
ipa-inline-analysis.c:2008 (inline_merge_summary 1697908: 2.5% 3086804
99582: 1.1%
ipa-reference.c:185 (set_reference_optimization_ 6122784: 9.0% 10353528
10: 0.0%
lto-cgraph.c:113 (lto_cgraph_encoder_encode) 6485840: 9.5% 10924352
22118: 0.2%
ipa-ref.c:59 (ipa_record_reference) 16005792:23.5% 20789048
534854: 6.0%
ipa-inline-analysis.c:647 (inline_summary_alloc) 17904344:26.3% 35257432
11486: 0.1%
passes.c:1893 (execute_one_pass) 18076256:26.5% 20971480
474948: 5.3%
Total 68129708
8892582
GGC stats:
ipa-inline-analysis.c:841 (inline_node_duplicati 0: 0.0% 42428:
0.0% 37876224: 2.3% 2058852: 0.6% 232982
gimple.c:4177 (iterative_hash_gimple_type) 43510016: 2.8% 0:
0.0% 0: 0.0% 0: 0.0% 2719376
lto-symtab.c:156 (lto_symtab_register_decl) 50215704: 3.3% 0:
0.0% 0: 0.0% 0: 0.0% 896709
lto-section-in.c:471 (lto_new_in_decl_state) 165360: 0.0% 0:
0.0% 51424080: 3.2% 0: 0.0% 429912
cgraph.c:1008 (cgraph_create_edge_1) 0: 0.0% 0:
0.0% 77585352: 4.8% 0: 0.0% 746013
lto-streamer-in.c:2477 (lto_input_ts_constructor 34780240: 2.3% 67555760:
8.4% 45650928: 2.8% 33677352:10.4% 271362
ipa-inline-analysis.c:643 (inline_summary_alloc) 0: 0.0% 0:
0.0% 85235448: 5.3% 18126584: 5.6% 1
ipa-ref.c:54 (ipa_record_reference) 0: 0.0%
171658064:21.4% 85633072: 5.3% 68326696:21.0% 554106
lto-streamer-in.c:1934 (lto_materialize_tree) 90241344: 5.9% 0:
0.0% 11233544: 0.7% 5872: 0.0% 1013612
lto/lto.c:217 (lto_read_in_decl_state) 333288: 0.0% 0:
0.0% 130600080: 8.1% 24601136: 7.6% 3009384
toplev.c:1027 (realloc_for_line_map) 0: 0.0%
167815168:20.9% 167778304:10.4% 67182592:20.7% 14
tree.c:1223 (build_int_cst_wide) 200129008:13.0% 0:
0.0% 2046496: 0.1% 66567480:20.5% 40217
cgraph.c:457 (cgraph_allocate_node) 0: 0.0% 0:
0.0% 226542712:14.0% 0: 0.0% 765347
lto-streamer-in.c:1939 (lto_materialize_tree) 1077917488:70.1% 0:
0.0% 540532272:33.4% 28671712: 8.8% 12277142
Total 1537795379 803354140
1619917572 325016043 27622283
source location Garbage Freed
Leak Overhead Times
Honza
