[Webkit-unassigned] [Bug 67176] JavaScriptCore does not have tiered compilation

bugzilla-daemon at webkit.org bugzilla-daemon at webkit.org
Mon Aug 29 19:21:48 PDT 2011


https://bugs.webkit.org/show_bug.cgi?id=67176





--- Comment #1 from Filip Pizlo <fpizlo at apple.com>  2011-08-29 19:21:48 PST ---
Here is the performance of tiered compilation, without any optimizations that would benefit from tiered compilation.  As in:

1) There is no profile-driven compilation.

2) We always JIT code.  The first tier JIT is the old JIT, and the second tier JIT is the DFG.

3) The DFG JIT is not so much more expensive than the old JIT that tiering would reduce compile times significantly.

As in, this is an worst-case scenario measurement - it gives us the worst-case pathological cost of not immediately compiling with the DFG.


Benchmark report for SunSpider, V8, and Kraken.

VMs tested:
"TipOfTree" at /Volumes/Data/pizlo/quinary/OpenSource/WebKitBuild/Release/jsc
"TieringEnabled" at /Volumes/Data/pizlo/octonary/OpenSource/WebKitBuild/Release/jsc

Collected 12 samples per benchmark/VM, with 4 VM invocations per benchmark. 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             TieringEnabled                                 
SunSpider:
   3d-cube                                7.5697+-0.1302    !     8.1947+-0.1789       ! definitely 1.0826x slower
   3d-morph                               7.3310+-0.1581    !     7.6346+-0.1198       ! definitely 1.0414x slower
   3d-raytrace                            7.5872+-0.1801    !     8.6595+-0.2115       ! definitely 1.1413x slower
   access-binary-trees                    2.3936+-0.1317    ?     2.4144+-0.0996       ?
   access-fannkuch                       11.7383+-0.1824    ?    12.0820+-0.2585       ? might be 1.0293x slower
   access-nbody                           4.2421+-0.0683    ?     4.3795+-0.1220       ? might be 1.0324x slower
   access-nsieve                          2.4851+-0.0591    !     2.6592+-0.0485       ! definitely 1.0701x slower
   bitops-3bit-bits-in-byte               1.7253+-0.0628    ?     1.8459+-0.0681       ? might be 1.0699x slower
   bitops-bits-in-byte                    4.5103+-0.2142    !     4.9207+-0.0933       ! definitely 1.0910x slower
   bitops-bitwise-and                     3.6722+-0.0712    !     4.0303+-0.1294       ! definitely 1.0975x slower
   bitops-nsieve-bits                     5.4084+-0.1234    ?     5.4185+-0.0880       ?
   controlflow-recursive                  2.0106+-0.0685    ?     2.0777+-0.0619       ? might be 1.0334x slower
   crypto-aes                             6.4807+-0.1584    !     7.1072+-0.2762       ! definitely 1.0967x slower
   crypto-md5                             2.8333+-0.0827    !     3.0637+-0.0605       ! definitely 1.0813x slower
   crypto-sha1                            2.1963+-0.0656    !     2.4276+-0.0576       ! definitely 1.1053x slower
   date-format-tofte                     10.1948+-0.3012    ?    10.3135+-0.3361       ? might be 1.0116x slower
   date-format-xparb                      8.3079+-0.1122    !     9.1526+-0.2566       ! definitely 1.1017x slower
   math-cordic                            6.4793+-0.3005    ?     6.5032+-0.1603       ?
   math-partial-sums                      7.7221+-0.1542          7.4640+-0.1467         might be 1.0346x faster
   math-spectral-norm                     2.4993+-0.0623    ?     2.6149+-0.0656       ? might be 1.0463x slower
   regexp-dna                            10.2265+-0.2753         10.0736+-0.2134         might be 1.0152x faster
   string-base64                          6.0017+-0.2027          6.0012+-0.0787       
   string-fasta                           7.4792+-0.2292          7.1326+-0.1780         might be 1.0486x faster
   string-tagcloud                       13.4894+-0.2745         13.0466+-0.2483         might be 1.0339x faster
   string-unpack-code                    18.3762+-0.3810    ?    19.0636+-0.4548       ? might be 1.0374x slower
   string-validate-input                  6.9764+-0.2309          6.8614+-0.2039         might be 1.0168x faster

   <arithmetic>                           6.5360+-0.0434    !     6.7363+-0.0402       ! definitely 1.0306x slower
   <geometric>                            5.4317+-0.0374    !     5.6435+-0.0279       ! definitely 1.0390x slower
   <harmonic>                             4.4484+-0.0301    !     4.6648+-0.0340       ! definitely 1.0486x slower

                                            TipOfTree             TieringEnabled                                 
V8:
   crypto                                90.1561+-0.4657    !    92.6007+-0.5567       ! definitely 1.0271x slower
   deltablue                            261.2825+-1.2059    !   265.1254+-1.7597       ! definitely 1.0147x slower
   earley-boyer                         101.1890+-0.4968    !   104.4750+-0.2499       ! definitely 1.0325x slower
   raytrace                              77.7841+-0.3200    ?    77.9236+-0.4897       ?
   regexp                               108.4768+-0.6381    !   111.4160+-0.3292       ! definitely 1.0271x slower
   richards                             241.2977+-1.2640    !   249.0259+-2.2002       ! definitely 1.0320x slower
   splay                                109.6627+-0.5339    ^   108.3732+-0.5277       ^ definitely 1.0119x faster

   <arithmetic>                         141.4070+-0.2960    !   144.1343+-0.6120       ! definitely 1.0193x slower
   <geometric>                          126.9741+-0.2363    !   129.1974+-0.3898       ! definitely 1.0175x slower
   <harmonic>                           116.3908+-0.2368    !   118.2490+-0.2897       ! definitely 1.0160x slower

                                            TipOfTree             TieringEnabled                                 
Kraken:
   ai-astar                            1099.4152+-8.6736    ^  1081.0538+-7.3193       ^ definitely 1.0170x faster
   audio-beat-detection                 464.7362+-1.6339    !   475.2486+-2.9215       ! definitely 1.0226x slower
   audio-dft                            421.8051+-3.9788    ?   423.8868+-3.3273       ?
   audio-fft                            374.3489+-3.1956    ^   369.9372+-0.9839       ^ definitely 1.0119x faster
   audio-oscillator                     375.2353+-0.4462    ^   357.1955+-3.6390       ^ definitely 1.0505x faster
   imaging-darkroom                     534.1020+-7.4953    ?   536.1056+-3.3782       ?
   imaging-desaturate                   591.7430+-6.5169    ?   596.3413+-6.6589       ?
   imaging-gaussian-blur               1727.0032+-7.2924    !  2019.4240+-18.6047      ! definitely 1.1693x slower
   json-parse-financial                  49.2286+-1.2706         48.5747+-0.3344         might be 1.0135x faster
   json-stringify-tinderbox              61.5364+-0.3364    ?    62.2929+-0.4507       ? might be 1.0123x slower
   stanford-crypto-aes                  145.0281+-0.7231    ?   147.0604+-1.3901       ? might be 1.0140x slower
   stanford-crypto-ccm                  110.8017+-0.2247    !   113.3705+-0.4937       ! definitely 1.0232x slower
   stanford-crypto-pbkdf2               337.3557+-1.4168    ?   339.8807+-3.2412       ?
   stanford-crypto-sha256-iterative     129.9748+-0.6521    ?   130.0296+-0.8055       ?

   <arithmetic>                         458.7367+-1.0545    !   478.6001+-1.4694       ! definitely 1.0433x slower
   <geometric>                          293.5137+-0.6624    !   296.9148+-0.5346       ! definitely 1.0116x slower
   <harmonic>                           179.3067+-1.1042    ?   179.8807+-0.5467       ?

                                            TipOfTree             TieringEnabled                                 
All benchmarks:
   <arithmetic>                         161.3213+-0.3186    !   167.7550+-0.4560       ! definitely 1.0399x slower
   <geometric>                           28.5043+-0.0949    !    29.2899+-0.0912       ! definitely 1.0276x slower
   <harmonic>                             7.8556+-0.0515    !     8.2301+-0.0588       ! definitely 1.0477x slower

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