Bug 74362 – DFG should know exactly why recompilation was triggered

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Filip Pizlo]

Currently the DFG can update predictions on OSR failure, which, in the case of recompilation, greatly reduces the likelihood that the DFG will repeat a broken type speculation on recompilation.  But the same is not true of slow case profiles.

[Filip Pizlo]

<rdar://problem/10568356>

[Filip Pizlo]

Created attachment 118894 [details]
work in progress

Still working on it.

[Filip Pizlo]

Created attachment 118905 [details]
work in progress

Patched in the code that identifies the kind of an OSR exit.  Still need to patch it into the parser as well, so that it can use this new information.

[Filip Pizlo]

Created attachment 118909 [details]
work in progress

Patched it into the parser, as well.

[Filip Pizlo]

Created attachment 118920 [details]
work in progress

I've checked that this does what it claims to do on simple programs, but I still need to run a bunch more tests.

[Filip Pizlo]

Looks like this is a minor win on some benchmarks, and never a major regression.


[pizlo@nitroflex bencher] ./bencher TipOfTree:/Volumes/Data/pizlo/quinary/OpenSource/WebKitBuild/Release/jsc SlowPathFreq:/Volumes/Data/pizlo/tertiary/OpenSource/WebKitBuild/Release/jsc --remote oldmac,bigmac
Packaging VM builds for remote hosts...
Sending VM builds to oldmac...
Running on oldmac...
376/376                                                           
Generating benchmark report at TipOfTree_SlowPathFreq_SunSpiderV8Kraken_20111213_0019_benchReport.txt

Benchmark report for SunSpider, V8, and Kraken on oldmac.local (MacPro4,1).

VMs tested:
"TipOfTree" at /Volumes/Data/pizlo/quinary/OpenSource/WebKitBuild/Release/jsc (r102562)
"SlowPathFreq" at /Volumes/Data/pizlo/tertiary/OpenSource/WebKitBuild/Release/jsc (r102562)

Collected 12 samples per benchmark/VM, with 4 VM invocations per benchmark. Emitted a call to gc() between sample
measurements. Used 1 benchmark iteration per VM invocation for warm-up. Used the jsc-specific preciseTime()
function to get microsecond-level timing. Reporting benchmark execution times with 95% confidence intervals in
milliseconds.

                                            TipOfTree              SlowPathFreq                                  
SunSpider:
   3d-cube                                8.8537+-0.0418          8.8348+-0.0360       
   3d-morph                              10.0126+-0.0337    ?    10.0364+-0.0569       ?
   3d-raytrace                            9.2705+-0.0833    ?     9.3075+-0.0829       ?
   access-binary-trees                    1.9180+-0.0113          1.9117+-0.0096       
   access-fannkuch                        9.0954+-0.0176    ?     9.1007+-0.0099       ?
   access-nbody                           4.7385+-0.0082    ?     4.7480+-0.0106       ?
   access-nsieve                          3.7839+-0.0161          3.7817+-0.0047       
   bitops-3bit-bits-in-byte               1.5116+-0.0262          1.4914+-0.0073         might be 1.0136x faster
   bitops-bits-in-byte                    6.1183+-0.0333          6.1153+-0.0153       
   bitops-bitwise-and                     3.9754+-0.0045          3.9723+-0.0054       
   bitops-nsieve-bits                     6.8446+-0.0439    ?     6.8711+-0.0342       ?
   controlflow-recursive                  2.8318+-0.0134          2.8117+-0.0151       
   crypto-aes                             8.6727+-0.0778    ?     8.7265+-0.0741       ?
   crypto-md5                             2.9831+-0.0511          2.9571+-0.0347       
   crypto-sha1                            2.6242+-0.0427    ?     2.6282+-0.0349       ?
   date-format-tofte                     12.8675+-0.0976    ?    13.0371+-0.2123       ? might be 1.0132x slower
   date-format-xparb                     12.0446+-0.0974         12.0009+-0.1378       
   math-cordic                            8.6462+-0.0370          8.6418+-0.0214       
   math-partial-sums                     12.5511+-0.0403    ?    12.5806+-0.0218       ?
   math-spectral-norm                     3.1285+-0.0067    ?     3.1378+-0.0046       ?
   regexp-dna                            10.7195+-0.0460         10.6978+-0.0606       
   string-base64                          5.1285+-0.0427    ?     5.1960+-0.0392       ? might be 1.0132x slower
   string-fasta                           8.7138+-0.0261          8.7121+-0.0231       
   string-tagcloud                       15.0303+-0.0631    ^    14.7932+-0.0552       ^ definitely 1.0160x faster
   string-unpack-code                    26.0091+-0.1118    ^    25.5598+-0.2073       ^ definitely 1.0176x faster
   string-validate-input                  6.7967+-0.0649          6.7567+-0.0726       

   <arithmetic> *                         7.8796+-0.0276          7.8619+-0.0286         might be 1.0023x faster
   <geometric>                            6.3770+-0.0228          6.3696+-0.0224         might be 1.0012x faster
   <harmonic>                             5.0324+-0.0197          5.0210+-0.0185         might be 1.0023x faster

                                            TipOfTree              SlowPathFreq                                  
V8:
   crypto                                91.9402+-0.2729    ?    92.4680+-0.3077       ?
   deltablue                            210.3022+-2.0088    ^   202.4297+-0.9445       ^ definitely 1.0389x faster
   earley-boyer                         119.7940+-1.0201    ?   119.9616+-1.7648       ?
   raytrace                              63.2143+-0.2426    ?    63.6921+-0.4632       ?
   regexp                               146.0133+-0.2159    !   147.0763+-0.3609       ! definitely 1.0073x slower
   richards                             168.4466+-0.5277    ?   169.0543+-0.9127       ?
   splay                                108.6495+-0.8520        107.1163+-1.0375         might be 1.0143x faster

   <arithmetic>                         129.7657+-0.3659    ^   128.8283+-0.4251       ^ definitely 1.0073x faster
   <geometric> *                        121.5136+-0.2987        121.0456+-0.3954         might be 1.0039x faster
   <harmonic>                           113.2842+-0.2703        113.1795+-0.3618         might be 1.0009x faster

                                            TipOfTree              SlowPathFreq                                  
Kraken:
   ai-astar                             895.9352+-0.8130    ?   896.4024+-0.4021       ?
   audio-beat-detection                 248.6911+-0.5466        248.5920+-0.6787       
   audio-dft                            333.3400+-2.7790        331.6210+-3.0525       
   audio-fft                            161.0966+-0.4296        161.0934+-0.7409       
   audio-oscillator                     342.2135+-5.6457    ?   353.6643+-7.7995       ? might be 1.0335x slower
   imaging-darkroom                     413.3798+-8.7537    ^   392.9760+-7.6859       ^ definitely 1.0519x faster
   imaging-desaturate                   287.2541+-0.2385    ?   287.2603+-0.1409       ?
   imaging-gaussian-blur                759.8175+-1.6110        758.5884+-0.3347       
   json-parse-financial                  84.5241+-0.4509    !    85.9248+-0.2761       ! definitely 1.0166x slower
   json-stringify-tinderbox              99.8472+-0.2651    ?   100.0103+-0.2507       ?
   stanford-crypto-aes                  142.0881+-0.9562        141.3378+-0.5837       
   stanford-crypto-ccm                  135.5311+-0.5801    ?   135.7462+-0.6035       ?
   stanford-crypto-pbkdf2               278.7077+-1.7176    ?   279.0637+-2.1180       ?
   stanford-crypto-sha256-iterative     116.7660+-0.4616        116.2726+-0.0987       

   <arithmetic> *                       307.0851+-0.7445        306.3252+-0.8887         might be 1.0025x faster
   <geometric>                          238.7213+-0.5459        238.4980+-0.6135         might be 1.0009x faster
   <harmonic>                           192.0314+-0.3293    ?   192.2999+-0.3633       ? might be 1.0014x slower

                                            TipOfTree              SlowPathFreq                                  
All benchmarks:
   <arithmetic>                         115.1579+-0.2095        114.7821+-0.3217         might be 1.0033x faster
   <geometric>                           29.0997+-0.0711         29.0564+-0.0847         might be 1.0015x faster
   <harmonic>                             8.8659+-0.0342          8.8463+-0.0321         might be 1.0022x faster

                                            TipOfTree              SlowPathFreq                                  
Geomean of preferred means:
   <scaled-result>                       66.4958+-0.1303         66.3057+-0.1910         might be 1.0029x faster

Sending VM builds to bigmac...
Running on bigmac...
376/376                                                           
Generating benchmark report at TipOfTree_SlowPathFreq_SunSpiderV8Kraken_20111213_0023_benchReport.txt

Benchmark report for SunSpider, V8, and Kraken on bigmac.local (MacPro5,1).

VMs tested:
"TipOfTree" at /Volumes/Data/pizlo/quinary/OpenSource/WebKitBuild/Release/jsc (r102562)
"SlowPathFreq" at /Volumes/Data/pizlo/tertiary/OpenSource/WebKitBuild/Release/jsc (r102562)

Collected 12 samples per benchmark/VM, with 4 VM invocations per benchmark. Emitted a call to gc() between sample
measurements. Used 1 benchmark iteration per VM invocation for warm-up. Used the jsc-specific preciseTime()
function to get microsecond-level timing. Reporting benchmark execution times with 95% confidence intervals in
milliseconds.

                                            TipOfTree              SlowPathFreq                                  
SunSpider:
   3d-cube                                7.3496+-0.0191          7.3342+-0.0248       
   3d-morph                               8.3914+-0.1279    ?     8.4922+-0.1617       ? might be 1.0120x slower
   3d-raytrace                            7.7298+-0.0734          7.7275+-0.0661       
   access-binary-trees                    1.5971+-0.0062    ?     1.6089+-0.0161       ?
   access-fannkuch                        7.5285+-0.0065    ?     7.5354+-0.0162       ?
   access-nbody                           3.9722+-0.0376          3.9436+-0.0082       
   access-nsieve                          3.2177+-0.0644          3.1874+-0.0412       
   bitops-3bit-bits-in-byte               1.2329+-0.0050    ?     1.2454+-0.0142       ? might be 1.0101x slower
   bitops-bits-in-byte                    5.0886+-0.0433          5.0775+-0.0170       
   bitops-bitwise-and                     3.2872+-0.0044          3.2872+-0.0057       
   bitops-nsieve-bits                     5.6650+-0.0341    ?     5.6770+-0.0306       ?
   controlflow-recursive                  2.3524+-0.0171          2.3325+-0.0282       
   crypto-aes                             7.1755+-0.0338    ?     7.2163+-0.0356       ?
   crypto-md5                             2.4668+-0.0273    ?     2.4882+-0.0270       ?
   crypto-sha1                            2.1764+-0.0247    ?     2.1816+-0.0341       ?
   date-format-tofte                     10.5628+-0.0405    ?    10.7561+-0.1757       ? might be 1.0183x slower
   date-format-xparb                      9.8099+-0.0632    !    10.1406+-0.1309       ! definitely 1.0337x slower
   math-cordic                            7.2481+-0.0737          7.1668+-0.0421         might be 1.0113x faster
   math-partial-sums                     10.4499+-0.0604         10.4214+-0.0482       
   math-spectral-norm                     2.6001+-0.0034    ?     2.6060+-0.0026       ?
   regexp-dna                             8.8181+-0.0134    ?     8.8221+-0.0136       ?
   string-base64                          4.2187+-0.0183    ?     4.2351+-0.0269       ?
   string-fasta                           7.1984+-0.0136          7.1975+-0.0083       
   string-tagcloud                       12.4292+-0.0447    ^    12.2340+-0.0319       ^ definitely 1.0159x faster
   string-unpack-code                    20.9372+-0.1241         20.7755+-0.2039       
   string-validate-input                  5.5901+-0.0305    ?     5.6698+-0.0779       ? might be 1.0143x slower

   <arithmetic> *                         6.5036+-0.0209    ?     6.5138+-0.0189       ? might be 1.0016x slower
   <geometric>                            5.2804+-0.0171    ?     5.2912+-0.0176       ? might be 1.0020x slower
   <harmonic>                             4.1695+-0.0140    ?     4.1804+-0.0172       ? might be 1.0026x slower

                                            TipOfTree              SlowPathFreq                                  
V8:
   crypto                                75.9742+-0.1769    ?    76.3517+-0.2398       ?
   deltablue                            172.8290+-0.4310    ^   168.2014+-0.7885       ^ definitely 1.0275x faster
   earley-boyer                          99.1258+-0.9898    ?    99.3990+-1.3403       ?
   raytrace                              52.6548+-0.3492         52.6276+-0.4544       
   regexp                               122.8457+-0.3108    ?   123.3843+-0.7095       ?
   richards                             139.8939+-0.5605    ?   140.1635+-0.4490       ?
   splay                                 92.0049+-1.4515    ?    92.0586+-1.7017       ?

   <arithmetic>                         107.9040+-0.3600        107.4552+-0.3193         might be 1.0042x faster
   <geometric> *                        101.1485+-0.3840        100.9556+-0.3413         might be 1.0019x faster
   <harmonic>                            94.3474+-0.3875         94.3129+-0.3536         might be 1.0004x faster

                                            TipOfTree              SlowPathFreq                                  
Kraken:
   ai-astar                             826.8116+-0.6011        817.1519+-11.0256        might be 1.0118x faster
   audio-beat-detection                 203.4016+-0.7946        203.0116+-0.5714       
   audio-dft                            275.2446+-2.4037    ?   276.8894+-1.9989       ?
   audio-fft                            131.7718+-0.2776        131.7168+-0.2538       
   audio-oscillator                     285.5972+-4.8680        284.5543+-4.3878       
   imaging-darkroom                     345.3616+-7.5269    ^   323.4195+-6.6397       ^ definitely 1.0678x faster
   imaging-desaturate                   237.5173+-0.0433    ?   237.6266+-0.1685       ?
   imaging-gaussian-blur                626.0200+-0.1894    ?   626.1248+-0.2975       ?
   json-parse-financial                  69.9829+-0.2149    !    70.9664+-0.4633       ! definitely 1.0141x slower
   json-stringify-tinderbox              82.6340+-0.3166         82.4322+-0.1534       
   stanford-crypto-aes                  117.9230+-0.8331    ?   119.7628+-1.7808       ? might be 1.0156x slower
   stanford-crypto-ccm                  114.0365+-0.4470        113.6476+-0.5184       
   stanford-crypto-pbkdf2               228.7191+-0.6243    ?   230.2047+-1.7885       ?
   stanford-crypto-sha256-iterative      96.2021+-0.7075         96.0268+-0.4065       

   <arithmetic> *                       260.0874+-0.6421    ^   258.1097+-1.1704       ^ definitely 1.0077x faster
   <geometric>                          199.0161+-0.4565        198.3234+-0.6149         might be 1.0035x faster
   <harmonic>                           159.1484+-0.2925    ?   159.2616+-0.3870       ? might be 1.0007x slower

                                            TipOfTree              SlowPathFreq                                  
All benchmarks:
   <arithmetic>                          97.1414+-0.2101    ^    96.4911+-0.3598       ^ definitely 1.0067x faster
   <geometric>                           24.1635+-0.0588         24.1587+-0.0625         might be 1.0002x faster
   <harmonic>                             7.3461+-0.0242    ?     7.3649+-0.0297       ? might be 1.0026x slower

                                            TipOfTree              SlowPathFreq                                  
Geomean of preferred means:
   <scaled-result>                       55.5148+-0.1256         55.3673+-0.1331         might be 1.0027x faster

[Filip Pizlo]

Created attachment 118969 [details]
the patch

[WebKit Review Bot]

Attachment 118969 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/JavaScriptCore/ChangeLog', u'Source..." exit_code: 1

Source/JavaScriptCore/dfg/DFGOSRExit.h:85:  The parameter name "kind" adds no information, so it should be removed.  [readability/parameter_name] [5]
Source/JavaScriptCore/bytecode/DFGExitProfile.h:162:  The parameter name "site" adds no information, so it should be removed.  [readability/parameter_name] [5]
Total errors found: 2 in 18 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Filip Pizlo]

Created attachment 118970 [details]
the patch

Fix style.

[Early Warning System Bot]

Comment on attachment 118970 [details]
the patch

Attachment 118970 [details] did not pass qt-ews (qt):
Output: http://queues.webkit.org/results/10850281

[Filip Pizlo]

Created attachment 118973 [details]
the patch

Ooops, forgot to write the same code twice.

[Early Warning System Bot]

Comment on attachment 118973 [details]
the patch

Attachment 118973 [details] did not pass qt-ews (qt):
Output: http://queues.webkit.org/results/10847292

[Filip Pizlo]

Created attachment 118976 [details]
the patch

Forgot to add some build stuff.

[WebKit Review Bot]

Comment on attachment 118976 [details]
the patch

Clearing flags on attachment: 118976

Committed r102694: <http://trac.webkit.org/changeset/102694>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.