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[Bug rtl-optimization/8361] [3.3/3.4/4.0 regression] C++ compile-time performance regression
- From: "steven at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 12 Nov 2004 12:52:24 -0000
- Subject: [Bug rtl-optimization/8361] [3.3/3.4/4.0 regression] C++ compile-time performance regression
- References: <20021025133601.8361.gerald@pfeifer.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From steven at gcc dot gnu dot org 2004-11-12 12:52 -------
GCC 3.4 (CVS today) takes 35s usr on my machine.
GCC 4.0 (CVS today) takes 46s usr on the same machine.
The difference is entirely in DOM, into-SSA and SSA-other
which is really also into-SSA:
usr sys wall
dominator optimization 3.16 0.02 3.26
tree SSA rewrite 3.24 0.01 3.27
tree SSA other 3.47 0.09 3.40
Per-pass and cummulative time spent (top 10 only):
integration 1.09 2.30% 48.88%
tree PHI insertion 1.21 2.56% 51.44%
loop invariant motion 1.30 2.75% 54.18%
global alloc 1.30 2.75% 56.93%
CSE 1.72 3.63% 60.56%
parser 3.05 6.44% 67.00%
dominator optimization 3.16 6.68% 73.68%
tree SSA rewrite 3.24 6.84% 80.52%
tree SSA other 3.47 7.33% 87.85%
expand 5.75 12.15% 100.00%
Flat profile:
Each sample counts as 0.01 seconds.
% cumulative self self total
time seconds seconds calls s/call s/call name
1.82 8.19 8.19 13878865 0.00 0.00 is_gimple_reg
1.50 14.95 6.76 6594 0.00 0.00 synth_mult
1.28 20.69 5.74 12785589 0.00 0.00 ggc_alloc_stat
1.27 26.38 5.69 3433257 0.00 0.00 free_df_for_stmt
1.25 32.01 5.63 16868123 0.00 0.00 bitmap_set_bit
1.19 37.35 5.34 4846931 0.00 0.00 get_stmt_operands
1.17 42.59 5.24 62034 0.00 0.00 alloc_page
1.15 47.75 5.16 3559 0.00 0.01 compute_immediate_uses
0.99 52.18 4.43 6408238 0.00 0.00 htab_find_slot_with_hash
0.98 56.60 4.42 2104725 0.00 0.00 compute_immediate_uses_for_phi
0.93 60.76 4.16 821051 0.00 0.00 gt_ggc_mx_lang_tree_node
0.91 64.83 4.07 7802758 0.00 0.00 register_new_def
0.90 68.87 4.04 951728 0.00 0.00 rewrite_stmt
0.88 72.82 3.95 30035694 0.00 0.00 bitmap_bit_p
0.84 76.61 3.79 574332 0.00 0.00 cse_insn
0.81 80.26 3.65 196671 0.00 0.00 compute_global_livein
0.81 83.91 3.65 177070 0.00 0.00 insert_phi_nodes_for
0.81 87.54 3.63 2697441 0.00 0.00 for_each_rtx
0.81 91.16 3.62 1079773 0.00 0.00 check_phi_redundancy
which is a different way of saying "all over the map" :-(
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361