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[Bug c++/13776] [tree-ssa] Many C++ compile-time regression in 3.5-tree-ssa 040120
- From: "rguenth at tat dot physik dot uni-tuebingen dot de" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 12 Mar 2004 23:34:29 -0000
- Subject: [Bug c++/13776] [tree-ssa] Many C++ compile-time regression in 3.5-tree-ssa 040120
- References: <20040120183908.13776.kgardas@objectsecurity.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2004-03-12 23:34 -------
Subject: Re: [tree-ssa] Many C++ compile-time regression in
3.5-tree-ssa 040120
Richard Guenther wrote:
> Compilation times in mode that matters to me (leafify enabled) degraded
> half an order of magnitude:
>
> g++-ssa (GCC) 3.5-tree-ssa 20040311 (merged 20040307)
>
> bellatrix:/tmp$ g++-ssa -O2 -o tramp3d-v2 tramp3d-v2.cpp -static
> -ftime-report
instrumented compiler gives:
Flat profile:
Each sample counts as 0.01 seconds.
% cumulative self self total
time seconds seconds calls Ks/call Ks/call name
15.51 183.22 183.22 726080 0.00 0.00
process_left_occs_and_kills
8.55 284.25 101.03 16644 0.00 0.00
create_and_insert_occ_in_preorder_dt_order
6.72 363.67 79.42 184430 0.00 0.00 compute_global_livein
6.54 440.93 77.26 16644 0.00 0.00 rename_1
3.13 477.86 36.93 16644 0.00 0.00 clear_all_eref_arrays
3.05 513.86 36.00 16644 0.00 0.00 compute_down_safety
2.49 543.32 29.46 152057062 0.00 0.00 expr_lexically_eq
2.09 568.00 24.68 201843 0.00 0.00 cgraph_remove_node
1.89 590.33 22.33 432753 0.00 0.00 alloc_page
1.70 610.44 20.11 eref_compare
1.70 630.47 20.03 158882 0.00 0.00 compute_transp
1.46 647.70 17.23 416131 0.00 0.00 cgraph_remove_edge
1.42 664.43 16.73 14808480 0.00 0.00
gt_ggc_mx_lang_tree_node
1.13 677.82 13.39 226466163 0.00 0.00 ggc_set_mark
1.07 690.43 12.61 1482 0.00 0.00 collect_expressions
0.90 701.05 10.62 15658237 0.00 0.00 walk_tree
i.e. PRE seems to do something very stupid?
Richard.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13776