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optimization/6007: cfg cleanup tremendous performance hog with -O1
- From: lucier at math dot purdue dot edu
- To: gcc-gnats at gcc dot gnu dot org
- Cc: feeley at iro dot umontreal dot ca
- Date: 19 Mar 2002 20:19:36 -0000
- Subject: optimization/6007: cfg cleanup tremendous performance hog with -O1
- Reply-to: lucier at math dot purdue dot edu
>Number: 6007
>Category: optimization
>Synopsis: cfg cleanup tremendous performance hog with -O1
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: unassigned
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Tue Mar 19 12:26:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator: B. Lucier
>Release: 3.1 20020318 (prerelease)
>Organization:
>Environment:
sparc-sun-solaris2.8
Solaris as/ld
>Description:
The input file is
http://www.math.purdue.edu/~lucier/GNATS/GNATS-4/all.i.gz
It takes about 16 hours and about 3 GB of memory to compile
this program on a 500 MHz UltraSPARC II. This is with a
profiled version of cc1.
There is no way that it should take this long with -O1.
-O1 is for local optimizations; it should be the
optimization level one can use when a routine is too large
to use -O2.
This is definitely a regression from 2.95*.
banach-169% /home/c/lucier/local/gcc-3.1/lib/gcc-lib/sparc-sun-solaris2.8/3.1/cc1 -fpreprocessed all.i -mptr64 -mstack-bias -mno-v8plus -dumpbase all.c -m64 -mcpu=ultrasparc -mtune=ultrasparc -O1 -Wall -W -Wno-unused -version -fPIC -fschedule-insns2 -fno-math-errno -fno-strict-aliasing -o all.s
GNU CPP version 3.1 20020318 (prerelease) (cpplib) (sparc ELF)
GNU C version 3.1 20020318 (prerelease) (sparc-sun-solaris2.8)
compiled by GNU C version 3.1 20020318 (prerelease).
options passed: -fpreprocessed -mptr64 -mstack-bias -mno-v8plus -m64
-mcpu=ultrasparc -mtune=ultrasparc -O1 -Wall -W -Wno-unused -fPIC
-fschedule-insns2 -fno-math-errno -fno-strict-aliasing
options enabled: -fdefer-pop -fomit-frame-pointer -fthread-jumps
-fpeephole -ffunction-cse -fkeep-static-consts -freg-struct-return
-fdelayed-branch -fgcse-lm -fgcse-sm -fschedule-insns2 -fsched-interblock
-fsched-spec -fbranch-count-reg -fPIC -fcprop-registers -fcommon
-fgnu-linker -fargument-alias -fmerge-constants -fident
-fguess-branch-probability -ftrapping-math -mepilogue -mptr64 -m64
-mstack-bias -mcpu=ultrasparc -mtune=ultrasparc
___H__20_all {GC 104370k -> 44446k} {GC 57858k -> 45642k} {GC 60148k -> 47950k} {GC 85130k -> 47937k} {GC 82606k -> 23072k} {GC 31452k -> 25858k} {GC 33844k -> 26890k} {GC 44252k -> 26464k} ___init_proc ____20_all
Execution times (seconds)
garbage collection : 12.87 ( 0%) usr 0.04 ( 0%) sys 17.00 ( 0%) wall
cfg construction : 341.31 ( 1%) usr 108.04 (47%) sys 449.00 ( 1%) wall
cfg cleanup :65630.05 (98%) usr 3.19 ( 1%) sys65995.00 (97%) wall
life analysis : 301.17 ( 0%) usr 0.02 ( 0%) sys 304.00 ( 0%) wall
life info update : 4.24 ( 0%) usr 0.00 ( 0%) sys 6.00 ( 0%) wall
preprocessing : 4.62 ( 0%) usr 4.01 ( 2%) sys 8.00 ( 0%) wall
lexical analysis : 5.38 ( 0%) usr 9.45 ( 4%) sys 16.00 ( 0%) wall
parser : 19.31 ( 0%) usr 5.38 ( 2%) sys 22.00 ( 0%) wall
expand : 10.77 ( 0%) usr 0.52 ( 0%) sys 11.00 ( 0%) wall
varconst : 2.87 ( 0%) usr 0.04 ( 0%) sys 3.00 ( 0%) wall
integration : 1.91 ( 0%) usr 0.08 ( 0%) sys 3.00 ( 0%) wall
jump : 1.85 ( 0%) usr 0.03 ( 0%) sys 2.00 ( 0%) wall
CSE : 26.05 ( 0%) usr 0.00 ( 0%) sys 25.00 ( 0%) wall
loop analysis : 0.15 ( 0%) usr 0.00 ( 0%) sys 0.00 ( 0%) wall
flow analysis : 435.58 ( 1%) usr 93.09 (40%) sys 530.00 ( 1%) wall
combiner : 37.52 ( 0%) usr 0.02 ( 0%) sys 37.00 ( 0%) wall
if-conversion : 35.11 ( 0%) usr 0.01 ( 0%) sys 36.00 ( 0%) wall
local alloc : 10.35 ( 0%) usr 0.00 ( 0%) sys 11.00 ( 0%) wall
global alloc : 85.55 ( 0%) usr 4.51 ( 2%) sys 134.00 ( 0%) wall
reload CSE regs : 220.85 ( 0%) usr 0.02 ( 0%) sys 223.00 ( 0%) wall
flow 2 : 11.20 ( 0%) usr 0.04 ( 0%) sys 15.00 ( 0%) wall
if-conversion 2 : 0.62 ( 0%) usr 0.03 ( 0%) sys 3.00 ( 0%) wall
rename registers : 6.03 ( 0%) usr 0.07 ( 0%) sys 9.00 ( 0%) wall
scheduling 2 : 12.87 ( 0%) usr 0.00 ( 0%) sys 12.00 ( 0%) wall
delay branch sched : 8.40 ( 0%) usr 0.00 ( 0%) sys 8.00 ( 0%) wall
shorten branches : 0.82 ( 0%) usr 0.00 ( 0%) sys 3.00 ( 0%) wall
final : 1.52 ( 0%) usr 0.03 ( 0%) sys 6.00 ( 0%) wall
rest of compilation : 11.21 ( 0%) usr 2.34 ( 1%) sys 188.00 ( 0%) wall
TOTAL :67240.23 230.97 68076.00
Here is the top of the profile. The whole gprof output
can be found at:
http://www.math.purdue.edu/~lucier/GNATS/GNATS-4/all.i.gprof.gz
Flat profile:
Each sample counts as 0.01 seconds.
% cumulative self self total
time seconds seconds calls s/call s/call name
37.31 1106.44 1106.44 2123667007 0.00 0.00 try_crossjump_to_edge
11.27 1440.70 334.26 internal_mcount
6.85 1643.67 202.97 395788 0.00 0.00 cselib_invalidate_regno
6.53 1837.39 193.72 htab_traverse
4.67 1975.95 138.56 4987 0.03 0.03 propagate_freq
2.87 2061.08 85.13 29 2.94 2.94 find_unreachable_blocks
2.50 2135.09 74.01 15 4.93 4.94 calc_idoms
2.48 2208.53 73.44 468802 0.00 0.00 try_forward_edges
2.46 2281.48 72.95 173160573 0.00 0.00 cached_make_edge
2.41 2353.01 71.53 175996207 0.00 0.00 bitmap_operation
2.14 2416.55 63.54 9 7.06 15.68 calculate_global_regs_live
2.14 2480.01 63.46 15 4.23 4.23 calc_dfs_tree_nonrec
1.90 2536.38 56.37 173039017 0.00 0.00 make_label_edge
1.60 2583.90 47.52 3 15.84 31.63 flow_loops_find
0.98 2613.04 29.14 173160566 0.00 0.00 free_edge
0.97 2641.89 28.85 5 5.77 5.77 mark_dfs_back_edges
0.70 2662.75 20.86 3 6.95 64.74 estimate_bb_frequencies
0.60 2680.56 17.81 __lshrdi3
0.56 2697.23 16.67 266211 0.00 0.00 record_one_conflict
0.55 2713.54 16.31 5058 0.00 0.00 flow_loop_exit_edges_find
0.55 2729.73 16.19 64492 0.00 0.00 purge_dead_edges
0.51 2744.83 15.10 43310765 0.00 0.00 remove_edge
>How-To-Repeat:
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted: