Bug 144001 – Make FunctionRareData allocation thread-safe

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

[Basile Clement]

Patch forthcoming.

[Basile Clement]

Created attachment 251293 [details]
Add fences in FunctionRareData::rareData() and FunctionRareData::rareData(ExecState, size_t inlineCapacity)

[Basile Clement]

Created attachment 251336 [details]
JSFunction's rare data + ObjectAllocationProfile's Structure&Allocator fenced

[Basile Clement]

I think the current fences are enough, here is my reasoning.

The two things we want to prevent are:

 1. A thread seeing a pointer to a not-yet-fully-created rare data from a JSFunction
 2. A thread seeing a pointer to a not-yet-fully-created Structure from an ObjectAllocationProfile

For 1., only the JS thread can be creating the rare data (in runtime/CommonSlowPaths.cpp or in dfg/DFGOperations.cpp), so we don't need to worry about concurrent writes, and we don't need any fences when *reading* the rare data from the JS thread. Thus we only need a storeStoreFence between the rare data creation and assignment to m_rareData in JSFunction::createAndInitializeRareData() to ensure that when the store to m_rareData is issued, the rare data has been properly created.

For the DFG compilation threads, the only place they can access the rare data is through JSFunction::rareData(), and so we only need a loadLoadFence there to ensure that when we see a non-null pointer in m_rareData, the pointed object will be seen as a fully created FunctionRareData.


For 2., the structure is created in ObjectAllocationProfile::initialize() (which appears to be called only by the JS thread as well, in bytecode/CodeBlock.cpp and on rare data initialization, which always happen in the JS thread), and read through ObjectAllocationProfile::structure() and ObjectAllocationProfile::inlineCapacity(), so following the same reasoning we put a storeStoreFence in ObjectAllocationProfile::initialize() and a loadLoadFence in ObjectAllocationProfile::structure() (and change ObjectAllocationProfile::inlineCapacity() to go through ObjectAllocationProfile::structure()).

We don't need a fence in ObjectAllocationProfile::clear() because clearing the structure is an atomic change.

Also notice that we don't care about the ObjectAllocationProfile's allocator as that is only used by ObjectAllocationProfile::initialize() and ObjectAllocationProfile::clear() that are always run in the JS thread.
ObjectAllocationProfile::isNull() could cause some trouble, but it looks like it is only used in the ObjectAllocationProfile::clear() check, which is also in the JS thread (trying to build w/ isNull() private to verify this).

[Basile Clement]

I was expecting this to be perf-neutral, but apparently it isn't?
I have run the Kraken benchmark several times w/ consistent results, but these numbers still seem really weird to me.

Benchmark report for SunSpider, LongSpider, V8Spider, Octane, Kraken, JSRegress, AsmBench, and CompressionBench on Basiles-MacBook-Pro (MacBookPro11,3).

VMs tested:
"Conf#1" at /Volumes/Data/SVN/Baseline/OpenSource/WebKitBuild/Release/jsc (r183114)
"Conf#2" at /Volumes/Data/SVN/WIP/OpenSource/WebKitBuild/Release/jsc (r183114)

Collected 6 samples per benchmark/VM, with 6 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.

                                                          Conf#1                    Conf#2                                      
SunSpider:
   3d-cube                                            4.4353+-0.1513     ?      4.6088+-0.4794        ? might be 1.0391x slower
   3d-morph                                           5.5881+-0.3794            5.3280+-0.2217          might be 1.0488x faster
   3d-raytrace                                        5.1925+-0.1924     ?      5.4993+-0.4735        ? might be 1.0591x slower
   access-binary-trees                                2.0345+-0.1422     ?      2.0935+-0.1290        ? might be 1.0290x slower
   access-fannkuch                                    5.4790+-0.1607     ?      5.5982+-0.3416        ? might be 1.0218x slower
   access-nbody                                       2.6063+-0.2451            2.5146+-0.0757          might be 1.0365x faster
   access-nsieve                                      3.3501+-0.1169            3.2323+-0.1266          might be 1.0364x faster
   bitops-3bit-bits-in-byte                           1.4320+-0.0569     ?      1.5517+-0.2076        ? might be 1.0836x slower
   bitops-bits-in-byte                                3.4915+-0.3205            3.2898+-0.2889          might be 1.0613x faster
   bitops-bitwise-and                                 2.0900+-0.1273     ?      2.1259+-0.2040        ? might be 1.0172x slower
   bitops-nsieve-bits                                 3.1307+-0.1492     ?      3.1919+-0.1255        ? might be 1.0195x slower
   controlflow-recursive                              2.1903+-0.1806     ^      1.9284+-0.0382        ^ definitely 1.1358x faster
   crypto-aes                                         3.8271+-0.6925     ?      3.8767+-0.4590        ? might be 1.0129x slower
   crypto-md5                                         2.1478+-0.0529     ?      2.1944+-0.1973        ? might be 1.0217x slower
   crypto-sha1                                        2.5313+-0.4351            2.5241+-0.2240        
   date-format-tofte                                  7.2346+-0.5479            7.0985+-0.2518          might be 1.0192x faster
   date-format-xparb                                  4.8761+-0.1878            4.8739+-0.1462        
   math-cordic                                        2.8952+-0.1415            2.7555+-0.0219          might be 1.0507x faster
   math-partial-sums                                  4.6932+-0.3237     ?      4.9536+-0.4962        ? might be 1.0555x slower
   math-spectral-norm                                 1.8273+-0.0941     ?      1.8685+-0.2294        ? might be 1.0226x slower
   regexp-dna                                         6.8654+-0.5735            6.6967+-0.2889          might be 1.0252x faster
   string-base64                                      4.4054+-0.3068            4.3634+-0.4383        
   string-fasta                                       6.2585+-0.3565            6.0610+-0.4245          might be 1.0326x faster
   string-tagcloud                                    8.6238+-0.1777     ?      8.8418+-0.3017        ? might be 1.0253x slower
   string-unpack-code                                20.1375+-1.0708           19.1556+-0.4400          might be 1.0513x faster
   string-validate-input                              4.5809+-0.1479     ?      4.7644+-0.6369        ? might be 1.0401x slower

   <arithmetic>                                       4.6894+-0.0408            4.6535+-0.0318          might be 1.0077x faster

                                                          Conf#1                    Conf#2                                      
LongSpider:
   3d-cube                                          832.3554+-15.6521         831.0989+-14.3630       
   3d-morph                                        1627.3334+-33.1397        1621.9746+-26.7117       
   3d-raytrace                                      694.9163+-16.7973    ?    701.6835+-7.6839        ?
   access-binary-trees                              883.6753+-7.8280     ?    892.4621+-6.1909        ?
   access-fannkuch                                  277.7843+-4.7717     ?    285.4883+-12.9451       ? might be 1.0277x slower
   access-nbody                                     585.0649+-14.4911    ?    606.5778+-21.0410       ? might be 1.0368x slower
   access-nsieve                                    688.0964+-15.0250    ?    688.3172+-9.0926        ?
   bitops-3bit-bits-in-byte                          43.7256+-2.6037           43.2418+-0.9959          might be 1.0112x faster
   bitops-bits-in-byte                               93.0723+-3.2182     ?     93.9191+-5.0233        ?
   bitops-nsieve-bits                               659.8131+-14.5542    ?    667.2841+-10.6044       ? might be 1.0113x slower
   controlflow-recursive                            493.0334+-23.9063         485.2687+-17.4088         might be 1.0160x faster
   crypto-aes                                       582.7811+-16.5314    ?    602.8807+-20.1678       ? might be 1.0345x slower
   crypto-md5                                       564.9390+-12.6393         562.1348+-8.9322        
   crypto-sha1                                      615.6455+-22.0219         614.1862+-12.7002       
   date-format-tofte                                542.0933+-12.4481    ?    554.2762+-11.1277       ? might be 1.0225x slower
   date-format-xparb                                681.9327+-9.1361          671.1212+-12.7448         might be 1.0161x faster
   math-cordic                                      537.7730+-10.6876    ?    542.5652+-16.6267       ?
   math-partial-sums                                462.7460+-8.4181     ?    465.7054+-10.7027       ?
   math-spectral-norm                               592.6882+-12.5627    ?    608.7194+-17.4317       ? might be 1.0270x slower
   string-base64                                    340.3506+-4.4849     ?    357.1724+-15.4188       ? might be 1.0494x slower
   string-fasta                                     404.1642+-6.5204          398.4764+-5.3441          might be 1.0143x faster
   string-tagcloud                                  206.3975+-3.3353     ?    210.4167+-8.5157        ? might be 1.0195x slower

   <geometric>                                      460.1916+-3.0129     ?    464.3788+-3.0547        ? might be 1.0091x slower

                                                          Conf#1                    Conf#2                                      
V8Spider:
   crypto                                            54.0349+-2.3798     ?     54.3095+-2.6325        ?
   deltablue                                         81.9799+-2.8865     ?     84.8230+-7.8300        ? might be 1.0347x slower
   earley-boyer                                      41.9612+-1.4242     ?     43.6582+-1.8849        ? might be 1.0404x slower
   raytrace                                          33.8180+-3.4671           32.9440+-2.1068          might be 1.0265x faster
   regexp                                            81.3009+-4.1615           78.2463+-3.9613          might be 1.0390x faster
   richards                                          78.2319+-2.0493           76.0116+-2.9068          might be 1.0292x faster
   splay                                             39.9360+-2.8778           36.8094+-2.4762          might be 1.0849x faster

   <geometric>                                       55.3134+-0.9687           54.5553+-1.1820          might be 1.0139x faster

                                                          Conf#1                    Conf#2                                      
Octane:
   encrypt                                           0.21501+-0.00498          0.21261+-0.00310         might be 1.0113x faster
   decrypt                                           3.65038+-0.07951          3.63887+-0.04564       
   deltablue                                x2       0.17133+-0.00322    ?     0.17166+-0.00195       ?
   earley                                            0.45896+-0.00373    ?     0.46667+-0.00666       ? might be 1.0168x slower
   boyer                                             6.27579+-0.16581          6.21558+-0.06588       
   navier-stokes                            x2       5.47150+-0.08585          5.41433+-0.04577         might be 1.0106x faster
   raytrace                                 x2       1.08489+-0.06070    ?     1.12508+-0.04542       ? might be 1.0370x slower
   richards                                 x2       0.10282+-0.00119          0.09898+-0.00300         might be 1.0388x faster
   splay                                    x2       0.37825+-0.01238          0.37564+-0.00729       
   regexp                                   x2      29.81069+-1.03843    ?    30.10510+-0.99517       ?
   pdfjs                                    x2      40.44447+-0.42128    ?    40.63084+-0.46205       ?
   mandreel                                 x2      48.65925+-0.57836         48.20755+-0.58695       
   gbemu                                    x2      36.29409+-0.80857    ?    37.29404+-2.90085       ? might be 1.0276x slower
   closure                                           0.51882+-0.01557    ?     0.53285+-0.02216       ? might be 1.0270x slower
   jquery                                            6.57081+-0.15217          6.52869+-0.14826       
   box2d                                    x2      11.03558+-0.16908    ?    11.05483+-0.17349       ?
   zlib                                     x2     374.78502+-23.58295   ?   380.38261+-5.38599       ? might be 1.0149x slower
   typescript                               x2     683.28288+-10.84315   ?   687.96252+-13.16831      ?

   <geometric>                                       6.13569+-0.02919    ?     6.15439+-0.06829       ? might be 1.0030x slower

                                                          Conf#1                    Conf#2                                      
Kraken:
   ai-astar                                          434.666+-22.080     ^     303.440+-7.230         ^ definitely 1.4325x faster
   audio-beat-detection                              100.509+-0.998      ?     103.678+-4.352         ? might be 1.0315x slower
   audio-dft                                         174.509+-2.672      ?     174.850+-10.737        ?
   audio-fft                                          82.892+-1.443             81.713+-3.502           might be 1.0144x faster
   audio-oscillator                                  188.824+-5.888      ?     191.953+-10.438        ? might be 1.0166x slower
   imaging-darkroom                                   99.557+-2.777      ?     101.775+-2.967         ? might be 1.0223x slower
   imaging-desaturate                                 61.896+-3.449      ?      63.477+-3.888         ? might be 1.0256x slower
   imaging-gaussian-blur                              92.599+-4.179      ?      92.918+-3.284         ?
   json-parse-financial                               39.892+-1.750      ?      40.628+-3.869         ? might be 1.0185x slower
   json-stringify-tinderbox                           54.225+-2.224      ?      55.813+-3.232         ? might be 1.0293x slower
   stanford-crypto-aes                                59.995+-1.289      ?      60.090+-4.229         ?
   stanford-crypto-ccm                                51.436+-5.030      ?      51.614+-4.797         ?
   stanford-crypto-pbkdf2                            162.319+-6.810            156.031+-2.616           might be 1.0403x faster
   stanford-crypto-sha256-iterative                   52.126+-1.789      ?      53.658+-1.888         ? might be 1.0294x slower

   <arithmetic>                                      118.246+-1.662      ^     109.403+-1.025         ^ definitely 1.0808x faster

                                                          Conf#1                    Conf#2                                      
JSRegress:
   abs-boolean                                        2.4167+-0.0478     ?      2.8230+-0.7388        ? might be 1.1681x slower
   adapt-to-double-divide                            16.8736+-1.0876           16.7283+-0.5923        
   aliased-arguments-getbyval                         1.1803+-0.1241     ?      1.4742+-0.5141        ? might be 1.2489x slower
   allocate-big-object                                2.7050+-0.5142            2.5432+-0.1782          might be 1.0636x faster
   arguments-named-and-reflective                    12.1755+-0.7318           11.8265+-0.6290          might be 1.0295x faster
   arguments-out-of-bounds                           11.0167+-0.8931     ?     11.1595+-0.5796        ? might be 1.0130x slower
   arguments-strict-mode                             10.5916+-0.6123           10.4898+-0.7511        
   arguments                                          9.6276+-0.4310            9.3225+-0.5027          might be 1.0327x faster
   arity-mismatch-inlining                            0.9342+-0.1754            0.8137+-0.0471          might be 1.1481x faster
   array-access-polymorphic-structure                 6.9198+-1.0319            6.2931+-0.5897          might be 1.0996x faster
   array-nonarray-polymorhpic-access                 29.2566+-1.3096           29.0380+-1.2310        
   array-prototype-every                             85.5088+-2.4437           85.1174+-2.0088        
   array-prototype-forEach                           82.9918+-1.8932     ?     84.7477+-5.5181        ? might be 1.0212x slower
   array-prototype-map                               93.4983+-4.7102           91.3628+-4.8674          might be 1.0234x faster
   array-prototype-some                              84.4172+-4.3054     ?     86.4408+-3.8639        ? might be 1.0240x slower
   array-splice-contiguous                           43.9795+-2.3918     ?     44.0281+-1.9634        ?
   array-with-double-add                              3.5132+-0.1293            3.4739+-0.1188          might be 1.0113x faster
   array-with-double-increment                        3.1622+-0.1935     ?      3.2814+-0.2808        ? might be 1.0377x slower
   array-with-double-mul-add                          4.2835+-0.1722     ?      4.3679+-0.2506        ? might be 1.0197x slower
   array-with-double-sum                              3.4087+-0.2409            3.2313+-0.0377          might be 1.0549x faster
   array-with-int32-add-sub                           5.9524+-0.2121     ?      6.0045+-0.3445        ?
   array-with-int32-or-double-sum                     3.5087+-0.3663            3.4414+-0.3217          might be 1.0196x faster
   ArrayBuffer-DataView-alloc-large-long-lived   
                                                     29.5104+-2.5135           29.2418+-2.7326        
   ArrayBuffer-DataView-alloc-long-lived             13.3108+-1.3882     ?     13.3159+-0.7134        ?
   ArrayBuffer-Int32Array-byteOffset                  3.8005+-0.2229            3.7770+-0.2651        
   ArrayBuffer-Int8Array-alloc-large-long-lived   
                                                     31.2364+-3.2885           28.3175+-1.0144          might be 1.1031x faster
   ArrayBuffer-Int8Array-alloc-long-lived-buffer   
                                                     21.8736+-1.3013     ?     22.3775+-1.1947        ? might be 1.0230x slower
   ArrayBuffer-Int8Array-alloc-long-lived            12.9710+-1.0949           12.0900+-0.2507          might be 1.0729x faster
   ArrayBuffer-Int8Array-alloc                       10.7196+-0.8474     ?     11.4655+-3.1165        ? might be 1.0696x slower
   asmjs_bool_bug                                     7.7023+-0.3996     ?      7.8442+-0.8108        ? might be 1.0184x slower
   assign-custom-setter-polymorphic                   2.5416+-0.1326     ?      2.6241+-0.3422        ? might be 1.0325x slower
   assign-custom-setter                               3.7146+-0.3140            3.6717+-0.1589          might be 1.0117x faster
   basic-set                                          7.7248+-0.3996     ?      8.1038+-0.8269        ? might be 1.0491x slower
   big-int-mul                                        3.6631+-0.3389            3.6445+-0.3519        
   boolean-test                                       3.1919+-0.7690            2.8603+-0.0607          might be 1.1159x faster
   branch-fold                                        3.6932+-0.1170            3.6468+-0.1287          might be 1.0127x faster
   by-val-generic                                     7.6178+-0.1708            7.4012+-0.1909          might be 1.0293x faster
   call-spread-apply                                 27.7551+-1.2217     ?     27.9482+-1.4726        ?
   call-spread-call                                  22.8534+-0.6498     ?     22.9357+-0.8219        ?
   captured-assignments                               0.4224+-0.0301            0.3942+-0.0422          might be 1.0717x faster
   cast-int-to-double                                 4.9629+-0.1371     ?      5.0190+-0.3199        ? might be 1.0113x slower
   cell-argument                                      6.5756+-0.3714            6.5167+-0.5087        
   cfg-simplify                                       2.9827+-0.0461     ?      3.0035+-0.2543        ?
   chain-getter-access                                9.5176+-0.2910            9.3426+-0.3532          might be 1.0187x faster
   cmpeq-obj-to-obj-other                            12.2694+-0.8453           12.0483+-1.4419          might be 1.0183x faster
   constant-test                                      4.5533+-0.0464     !      4.6884+-0.0769        ! definitely 1.0297x slower
   create-lots-of-functions                          10.0383+-1.9324     ?     10.0472+-0.5893        ?
   DataView-custom-properties                        35.1123+-3.1334     ?     35.8569+-3.8184        ? might be 1.0212x slower
   deconstructing-parameters-overridden-by-function   
                                                      0.4677+-0.1327     ?      0.5406+-0.2202        ? might be 1.1561x slower
   delay-tear-off-arguments-strictmode               12.7437+-0.5581     ?     12.8787+-0.3374        ? might be 1.0106x slower
   deltablue-varargs                                149.3834+-1.5594     ?    152.2106+-3.8107        ? might be 1.0189x slower
   destructuring-arguments                           14.9521+-1.6548     ?     15.4644+-1.3411        ? might be 1.0343x slower
   destructuring-swap                                 4.7980+-0.1448            4.7359+-0.1229          might be 1.0131x faster
   direct-arguments-getbyval                          1.1604+-0.0934     ?      1.1986+-0.1247        ? might be 1.0330x slower
   div-boolean-double                                 5.4127+-0.1479     ?      5.4220+-0.1604        ?
   div-boolean                                        8.5641+-0.1970            8.5043+-0.1811        
   double-get-by-val-out-of-bounds                    4.2892+-0.2478     ?      4.4900+-0.2344        ? might be 1.0468x slower
   double-pollution-getbyval                          9.2493+-0.5698            8.9575+-0.2614          might be 1.0326x faster
   double-pollution-putbyoffset                       3.9415+-0.1636     ?      5.3841+-3.4205        ? might be 1.3660x slower
   double-to-int32-typed-array-no-inline              2.0848+-0.0961            2.0504+-0.0869          might be 1.0168x faster
   double-to-int32-typed-array                        1.6521+-0.0420     ?      1.7169+-0.1121        ? might be 1.0392x slower
   double-to-uint32-typed-array-no-inline             2.2035+-0.1788            2.2030+-0.1939        
   double-to-uint32-typed-array                       1.7822+-0.0766            1.7768+-0.0435        
   elidable-new-object-dag                           38.8936+-4.9598           37.5815+-3.4315          might be 1.0349x faster
   elidable-new-object-roflcopter                    42.0613+-3.1489           40.9705+-3.9674          might be 1.0266x faster
   elidable-new-object-then-call                     33.8572+-2.9101           33.3957+-1.5640          might be 1.0138x faster
   elidable-new-object-tree                          40.0110+-3.3110     ?     40.3750+-3.3847        ?
   empty-string-plus-int                              4.8594+-0.2043     ?      5.1221+-0.5582        ? might be 1.0541x slower
   emscripten-cube2hash                              29.4589+-0.9935           29.2051+-1.6557        
   exit-length-on-plain-object                       13.1971+-0.7219     ?     13.7371+-0.7052        ? might be 1.0409x slower
   external-arguments-getbyval                        1.2583+-0.1615     ?      1.3683+-0.2537        ? might be 1.0875x slower
   external-arguments-putbyval                        2.2881+-0.4736            2.2376+-0.1925          might be 1.0226x faster
   fixed-typed-array-storage-var-index                1.2150+-0.1091            1.2031+-0.1363        
   fixed-typed-array-storage                          0.9455+-0.3363            0.8676+-0.1480          might be 1.0898x faster
   Float32Array-matrix-mult                           3.9729+-0.3510            3.8196+-0.0688          might be 1.0402x faster
   Float32Array-to-Float64Array-set                  50.8818+-3.1112     ?     52.5493+-3.3516        ? might be 1.0328x slower
   Float64Array-alloc-long-lived                     68.5358+-7.2021     ?     69.2657+-5.3305        ? might be 1.0106x slower
   Float64Array-to-Int16Array-set                    61.7324+-2.1826     ?     63.4322+-2.2190        ? might be 1.0275x slower
   fold-double-to-int                                12.9622+-0.3145     ?     13.0689+-0.4892        ?
   fold-get-by-id-to-multi-get-by-offset-rare-int   
                                                     10.4813+-0.7112            9.9407+-0.6032          might be 1.0544x faster
   fold-get-by-id-to-multi-get-by-offset              7.9404+-0.7041            7.8822+-0.4075        
   fold-multi-get-by-offset-to-get-by-offset   
                                                      8.5785+-1.0104            7.6311+-1.2708          might be 1.1241x faster
   fold-multi-get-by-offset-to-poly-get-by-offset   
                                                      7.3379+-1.1628            6.9028+-1.1903          might be 1.0630x faster
   fold-multi-put-by-offset-to-poly-put-by-offset   
                                                      7.1982+-0.7196     ?      7.7133+-1.5306        ? might be 1.0716x slower
   fold-multi-put-by-offset-to-put-by-offset   
                                                      4.3297+-0.7220            4.3253+-0.5187        
   fold-multi-put-by-offset-to-replace-or-transition-put-by-offset   
                                                      9.5320+-1.0301            8.9991+-0.8375          might be 1.0592x faster
   fold-put-by-id-to-multi-put-by-offset              8.7173+-0.6786            8.4754+-0.6840          might be 1.0285x faster
   fold-put-structure                                 4.1141+-0.6161            3.7417+-0.2409          might be 1.0995x faster
   for-of-iterate-array-entries                       4.1770+-0.1260     ?      4.2598+-0.1427        ? might be 1.0198x slower
   for-of-iterate-array-keys                          3.4222+-0.4347            3.2863+-0.1032          might be 1.0413x faster
   for-of-iterate-array-values                        3.8211+-0.6362            3.3150+-0.1867          might be 1.1527x faster
   fround                                            18.9028+-1.2775           18.4106+-1.0793          might be 1.0267x faster
   ftl-library-inlining-dataview                     62.4405+-1.9515     ?     62.8280+-2.3589        ?
   ftl-library-inlining                             119.3035+-4.4261          116.3825+-4.2533          might be 1.0251x faster
   function-dot-apply                                 2.0017+-0.0707     ?      2.0693+-0.0447        ? might be 1.0337x slower
   function-test                                      2.9897+-0.1040     ?      3.0708+-0.2172        ? might be 1.0271x slower
   function-with-eval                                98.1050+-6.6907           97.3850+-2.4958        
   gcse-poly-get-less-obvious                        15.2463+-0.4843     ?     15.3335+-0.7207        ?
   gcse-poly-get                                     16.9200+-0.4172           16.9054+-0.8368        
   gcse                                               3.8682+-0.2160     ?      3.9013+-0.1458        ?
   get-by-id-bimorphic-check-structure-elimination-simple   
                                                      2.7301+-0.1596     ?      2.8475+-0.4200        ? might be 1.0430x slower
   get-by-id-bimorphic-check-structure-elimination   
                                                      6.0665+-0.4300            5.9204+-0.1839          might be 1.0247x faster
   get-by-id-chain-from-try-block                     7.0569+-0.5146            6.8019+-0.2569          might be 1.0375x faster
   get-by-id-check-structure-elimination              4.7083+-0.6591            4.5090+-0.0962          might be 1.0442x faster
   get-by-id-proto-or-self                           14.5393+-0.6130     ?     15.1705+-1.0026        ? might be 1.0434x slower
   get-by-id-quadmorphic-check-structure-elimination-simple   
                                                      2.9860+-0.1442            2.9550+-0.1453          might be 1.0105x faster
   get-by-id-self-or-proto                           15.5522+-1.4049           15.4950+-0.7216        
   get-by-val-out-of-bounds                           4.0091+-0.1338     ?      4.2081+-0.2444        ? might be 1.0496x slower
   get_callee_monomorphic                             2.4390+-0.2349     ?      2.5741+-0.2855        ? might be 1.0554x slower
   get_callee_polymorphic                             3.5576+-0.1683     ?      3.6161+-0.3018        ? might be 1.0164x slower
   getter-no-activation                               4.9987+-0.3392     ?      5.1001+-0.4686        ? might be 1.0203x slower
   getter-richards                                  115.4798+-6.8709     ?    121.8240+-7.8064        ? might be 1.0549x slower
   getter                                             5.2617+-0.2036     ?      5.7078+-0.5992        ? might be 1.0848x slower
   global-var-const-infer-fire-from-opt               0.8716+-0.1633     ?      0.9450+-0.1441        ? might be 1.0842x slower
   global-var-const-infer                             0.8320+-0.1120     ?      0.9356+-0.1235        ? might be 1.1245x slower
   HashMap-put-get-iterate-keys                      24.3960+-0.7000           24.0010+-0.5066          might be 1.0165x faster
   HashMap-put-get-iterate                           24.6828+-1.0917     ?     24.7902+-0.5964        ?
   HashMap-string-put-get-iterate                    25.5018+-2.9609           23.8171+-1.4325          might be 1.0707x faster
   hoist-make-rope                                    8.9097+-1.5407     ?      9.1958+-0.9647        ? might be 1.0321x slower
   hoist-poly-check-structure-effectful-loop   
                                                      4.4798+-0.6212            4.2600+-0.1759          might be 1.0516x faster
   hoist-poly-check-structure                         3.3848+-0.2386     ?      3.3925+-0.1887        ?
   imul-double-only                                   6.9112+-0.4667     ?      7.7718+-1.2264        ? might be 1.1245x slower
   imul-int-only                                      9.0255+-1.0025            8.6974+-0.3245          might be 1.0377x faster
   imul-mixed                                         7.0025+-0.4039            6.9930+-0.6957        
   in-four-cases                                     16.1306+-0.6578           15.8482+-0.6254          might be 1.0178x faster
   in-one-case-false                                  8.7791+-0.6551     ?      8.8798+-1.0469        ? might be 1.0115x slower
   in-one-case-true                                   8.9371+-0.5134     ?      9.2900+-1.0707        ? might be 1.0395x slower
   in-two-cases                                       9.4810+-1.1853            9.1688+-0.8586          might be 1.0340x faster
   indexed-properties-in-objects                      3.3002+-0.4603            3.0675+-0.5033          might be 1.0759x faster
   infer-closure-const-then-mov-no-inline             3.1357+-0.0943            3.1094+-0.1607        
   infer-closure-const-then-mov                      18.2635+-1.2450           17.5389+-0.6736          might be 1.0413x faster
   infer-closure-const-then-put-to-scope-no-inline   
                                                     14.2855+-1.2141           13.7454+-1.3018          might be 1.0393x faster
   infer-closure-const-then-put-to-scope             25.1483+-1.5993           24.2054+-0.7731          might be 1.0390x faster
   infer-closure-const-then-reenter-no-inline   
                                                     63.0570+-1.6493     ?     65.1399+-2.4728        ? might be 1.0330x slower
   infer-closure-const-then-reenter                  26.2822+-1.8759           24.5947+-0.7131          might be 1.0686x faster
   infer-constant-global-property                    32.7149+-2.3522           31.6355+-0.7032          might be 1.0341x faster
   infer-constant-property                            2.6896+-0.2072            2.5971+-0.0224          might be 1.0356x faster
   infer-one-time-closure-ten-vars                    8.9458+-0.8092     ?      9.1481+-0.6326        ? might be 1.0226x slower
   infer-one-time-closure-two-vars                    8.3568+-0.4844            8.3114+-0.2080        
   infer-one-time-closure                             8.2540+-0.5320            8.0311+-0.2146          might be 1.0278x faster
   infer-one-time-deep-closure                       13.4673+-0.5099     ?     13.6945+-0.6222        ? might be 1.0169x slower
   inline-arguments-access                            4.7100+-1.2382            4.1682+-0.2451          might be 1.1300x faster
   inline-arguments-aliased-access                    3.8919+-0.1417     ?      4.0637+-0.3933        ? might be 1.0441x slower
   inline-arguments-local-escape                      4.2133+-0.2358     ?      4.2351+-0.6076        ?
   inline-get-scoped-var                              4.7782+-0.2465            4.6715+-0.1311          might be 1.0228x faster
   inlined-put-by-id-transition                      10.4067+-1.2255     ?     10.8631+-0.9509        ? might be 1.0439x slower
   int-or-other-abs-then-get-by-val                   4.9307+-0.4399            4.6764+-0.1379          might be 1.0544x faster
   int-or-other-abs-zero-then-get-by-val             17.0365+-1.0412           16.9250+-0.4475        
   int-or-other-add-then-get-by-val                   4.1591+-0.3232            3.9647+-0.0693          might be 1.0490x faster
   int-or-other-add                                   4.9397+-0.1705     ?      4.9594+-0.2071        ?
   int-or-other-div-then-get-by-val                   3.9275+-0.0851     ?      4.4276+-0.5979        ? might be 1.1273x slower
   int-or-other-max-then-get-by-val                   4.1619+-0.3147            4.1224+-0.2884        
   int-or-other-min-then-get-by-val                   4.0415+-0.1020     ?      4.1794+-0.2763        ? might be 1.0341x slower
   int-or-other-mod-then-get-by-val                   3.7520+-0.1917            3.7306+-0.1455        
   int-or-other-mul-then-get-by-val                   3.7437+-0.1302     ?      3.8400+-0.1927        ? might be 1.0257x slower
   int-or-other-neg-then-get-by-val                   4.3582+-0.1546     ?      4.5470+-0.3540        ? might be 1.0433x slower
   int-or-other-neg-zero-then-get-by-val             16.6822+-0.3658     ?     16.9685+-0.6315        ? might be 1.0172x slower
   int-or-other-sub-then-get-by-val                   4.1799+-0.2960            4.1213+-0.1811          might be 1.0142x faster
   int-or-other-sub                                   3.5047+-0.3617     ?      3.5776+-0.3126        ? might be 1.0208x slower
   int-overflow-local                                 4.1756+-0.2734            4.0972+-0.1606          might be 1.0191x faster
   Int16Array-alloc-long-lived                       50.0232+-3.5200           49.4485+-5.4940          might be 1.0116x faster
   Int16Array-bubble-sort-with-byteLength            18.7257+-1.9756           18.0610+-0.4210          might be 1.0368x faster
   Int16Array-bubble-sort                            17.6900+-0.6539           17.5111+-0.4134          might be 1.0102x faster
   Int16Array-load-int-mul                            1.4528+-0.0929            1.4059+-0.0468          might be 1.0333x faster
   Int16Array-to-Int32Array-set                      47.7124+-1.7959           46.6479+-1.8089          might be 1.0228x faster
   Int32Array-alloc-large                            14.2405+-2.0780           13.1156+-0.9148          might be 1.0858x faster
   Int32Array-alloc-long-lived                       52.6025+-2.9181     ?     53.1608+-2.5637        ? might be 1.0106x slower
   Int32Array-alloc                                   2.8603+-0.2361     ?      2.8843+-0.2397        ?
   Int32Array-Int8Array-view-alloc                    6.8857+-1.1322            6.3975+-0.2348          might be 1.0763x faster
   int52-spill                                        6.0297+-0.2357            5.8714+-0.2345          might be 1.0270x faster
   Int8Array-alloc-long-lived                        44.1742+-3.1438     ?     45.1311+-5.0734        ? might be 1.0217x slower
   Int8Array-load-with-byteLength                     3.5967+-0.3884            3.5354+-0.2613          might be 1.0173x faster
   Int8Array-load                                     3.3956+-0.1306     ?      3.5472+-0.2857        ? might be 1.0446x slower
   integer-divide                                    11.1696+-0.6322           11.1178+-0.3585        
   integer-modulo                                     1.7227+-0.1354     ?      1.7573+-0.2303        ? might be 1.0201x slower
   large-int-captured                                 4.2350+-0.3715     ?      4.2855+-0.2902        ? might be 1.0119x slower
   large-int-neg                                     15.0682+-0.3768     ?     15.1535+-0.5773        ?
   large-int                                         14.2997+-0.2745     ?     15.3568+-1.2258        ? might be 1.0739x slower
   logical-not                                        4.4715+-0.3244            4.2217+-0.2594          might be 1.0592x faster
   lots-of-fields                                    10.6672+-0.7729     ?     10.9335+-0.5022        ? might be 1.0250x slower
   make-indexed-storage                               2.7259+-0.2566     ?      3.0432+-0.2270        ? might be 1.1164x slower
   make-rope-cse                                      3.9144+-0.2405            3.7549+-0.1004          might be 1.0425x faster
   marsaglia-larger-ints                             35.2551+-1.8262     ?     35.5552+-2.5509        ?
   marsaglia-osr-entry                               21.7434+-0.7198     ?     22.5769+-1.3098        ? might be 1.0383x slower
   max-boolean                                        2.7700+-0.0831            2.6952+-0.0599          might be 1.0278x faster
   method-on-number                                  17.7487+-1.3370           17.2074+-0.3127          might be 1.0315x faster
   min-boolean                                        2.7546+-0.1671            2.6766+-0.1225          might be 1.0291x faster
   minus-boolean-double                               3.1838+-0.2049            3.1503+-0.1162          might be 1.0106x faster
   minus-boolean                                      2.4468+-0.3131            2.3403+-0.0537          might be 1.0455x faster
   misc-strict-eq                                    32.0657+-3.0548           30.9404+-0.6344          might be 1.0364x faster
   mod-boolean-double                                11.6159+-0.6137           11.5835+-0.3905        
   mod-boolean                                        8.5605+-0.0809     ?      8.7320+-0.4243        ? might be 1.0200x slower
   mul-boolean-double                                 3.8188+-0.2741            3.7526+-0.2638          might be 1.0176x faster
   mul-boolean                                        2.9638+-0.1526            2.7923+-0.0512          might be 1.0614x faster
   neg-boolean                                        3.0915+-0.0774     ?      3.1283+-0.1542        ? might be 1.0119x slower
   negative-zero-divide                               0.3129+-0.0254            0.3111+-0.0286        
   negative-zero-modulo                               0.3678+-0.1594            0.2966+-0.0231          might be 1.2401x faster
   negative-zero-negate                               0.3048+-0.0708            0.2813+-0.0251          might be 1.0835x faster
   nested-function-parsing                           35.4219+-2.8303           34.0065+-0.9362          might be 1.0416x faster
   new-array-buffer-dead                             98.6464+-4.5235           96.4295+-5.6975          might be 1.0230x faster
   new-array-buffer-push                              6.0331+-0.2927     ?      6.6875+-1.3320        ? might be 1.1085x slower
   new-array-dead                                    13.8396+-0.7789     ?     15.3411+-1.4017        ? might be 1.1085x slower
   new-array-push                                     3.5367+-0.1052            3.4415+-0.3015          might be 1.0277x faster
   no-inline-constructor                            111.0593+-2.3227          106.3672+-4.3100          might be 1.0441x faster
   number-test                                        2.9524+-0.1849            2.9148+-0.1279          might be 1.0129x faster
   object-closure-call                                5.1482+-0.4793            5.0535+-0.2463          might be 1.0187x faster
   object-test                                        2.8591+-0.0648     ?      2.9816+-0.3384        ? might be 1.0428x slower
   obvious-sink-pathology-taken                     111.9813+-4.2488          109.4659+-6.0788          might be 1.0230x faster
   obvious-sink-pathology                           108.2312+-7.0478          104.2853+-6.4327          might be 1.0378x faster
   obviously-elidable-new-object                     30.7822+-2.3513     ?     31.8637+-1.5855        ? might be 1.0351x slower
   plus-boolean-arith                                 2.4429+-0.1379            2.4294+-0.1210        
   plus-boolean-double                                3.2247+-0.1970            3.1247+-0.0968          might be 1.0320x faster
   plus-boolean                                       2.5488+-0.0699     ?      2.6059+-0.1741        ? might be 1.0224x slower
   poly-chain-access-different-prototypes-simple   
                                                      2.8197+-0.2496     ?      2.8395+-0.1731        ?
   poly-chain-access-different-prototypes             2.4945+-0.0609     ?      2.6626+-0.1697        ? might be 1.0674x slower
   poly-chain-access-simpler                          2.7429+-0.1150            2.6925+-0.0250          might be 1.0187x faster
   poly-chain-access                                  2.6879+-0.3927            2.6584+-0.3185          might be 1.0111x faster
   poly-stricteq                                     54.8625+-2.3990     ?     55.5979+-3.7765        ? might be 1.0134x slower
   polymorphic-array-call                             1.2641+-0.4155            1.2065+-0.1826          might be 1.0478x faster
   polymorphic-get-by-id                              2.8175+-0.0427     ?      2.8947+-0.1137        ? might be 1.0274x slower
   polymorphic-put-by-id                             26.9848+-1.1718           26.1658+-0.6853          might be 1.0313x faster
   polymorphic-structure                             13.6088+-0.5545     ?     13.8648+-0.2574        ? might be 1.0188x slower
   polyvariant-monomorphic-get-by-id                  7.1073+-1.3167            7.0912+-0.7548        
   proto-getter-access                                9.4326+-0.3320     ?      9.4626+-0.4573        ?
   put-by-id-replace-and-transition                   8.1292+-0.3976     ?      8.9200+-1.5409        ? might be 1.0973x slower
   put-by-id-slightly-polymorphic                     2.7738+-0.4763            2.7209+-0.2497          might be 1.0194x faster
   put-by-id                                         10.2069+-0.3066     ?     10.8580+-1.2601        ? might be 1.0638x slower
   put-by-val-direct                                  0.3853+-0.0213            0.3809+-0.0430          might be 1.0115x faster
   put-by-val-large-index-blank-indexing-type   
                                                      5.7926+-0.5807            5.3792+-0.6324          might be 1.0769x faster
   put-by-val-machine-int                             2.7236+-0.2734            2.5609+-0.1057          might be 1.0635x faster
   rare-osr-exit-on-local                            15.1539+-0.4465     ?     15.3346+-0.3351        ? might be 1.0119x slower
   register-pressure-from-osr                        17.8601+-0.2759     ?     18.4645+-1.4084        ? might be 1.0338x slower
   setter                                             5.7569+-0.3490            5.7215+-0.1335        
   simple-activation-demo                            25.7653+-1.1622     ?     27.1953+-2.1483        ? might be 1.0555x slower
   simple-getter-access                              12.6530+-0.7928           12.3588+-0.2583          might be 1.0238x faster
   simple-poly-call-nested                            9.6672+-0.8043            9.4338+-0.3212          might be 1.0247x faster
   simple-poly-call                                   1.2802+-0.2142            1.2644+-0.2409          might be 1.0125x faster
   sin-boolean                                       19.2299+-1.9395     ?     19.5778+-2.1724        ? might be 1.0181x slower
   singleton-scope                                   65.5336+-2.1845     ?     68.9616+-4.7326        ? might be 1.0523x slower
   sinkable-new-object-dag                           61.6789+-4.1304     ?     62.1704+-3.5265        ?
   sinkable-new-object-taken                         48.3709+-2.9668           48.2065+-2.4714        
   sinkable-new-object                               34.1097+-2.3564           33.1188+-2.6903          might be 1.0299x faster
   slow-array-profile-convergence                     2.6855+-0.2409            2.6090+-0.1579          might be 1.0294x faster
   slow-convergence                                   2.5417+-0.2627            2.5209+-0.1934        
   sorting-benchmark                                 23.2951+-1.1998           22.1348+-0.7030          might be 1.0524x faster
   sparse-conditional                                 1.1222+-0.0467     ?      1.3260+-0.5395        ? might be 1.1816x slower
   splice-to-remove                                  14.9962+-0.8462           14.2574+-0.3521          might be 1.0518x faster
   string-char-code-at                               15.3922+-1.1045     ?     15.8472+-0.6751        ? might be 1.0296x slower
   string-concat-object                               2.2163+-0.1407     ?      2.5015+-0.1543        ? might be 1.1287x slower
   string-concat-pair-object                          2.2235+-0.1529     ?      2.2640+-0.1439        ? might be 1.0182x slower
   string-concat-pair-simple                         10.0750+-0.8607            9.9739+-0.8822          might be 1.0101x faster
   string-concat-simple                              10.4784+-1.0256           10.1696+-1.1498          might be 1.0304x faster
   string-cons-repeat                                 7.3133+-0.8916            7.1814+-0.6686          might be 1.0184x faster
   string-cons-tower                                  7.6784+-1.1937            7.4449+-1.1918          might be 1.0314x faster
   string-equality                                   15.2191+-0.2651     ?     15.7612+-0.5652        ? might be 1.0356x slower
   string-get-by-val-big-char                         7.2392+-1.4160            6.7185+-0.1084          might be 1.0775x faster
   string-get-by-val-out-of-bounds-insane             3.3553+-0.2733     ?      3.4134+-0.2755        ? might be 1.0173x slower
   string-get-by-val-out-of-bounds                    4.1635+-0.1638     ?      4.2227+-0.3365        ? might be 1.0142x slower
   string-get-by-val                                  2.8412+-0.1197     ?      2.9137+-0.2432        ? might be 1.0255x slower
   string-hash                                        1.9895+-0.3024            1.8647+-0.0790          might be 1.0669x faster
   string-long-ident-equality                        13.1139+-0.7039           12.9958+-0.4658        
   string-out-of-bounds                              10.7131+-0.3183     ?     11.3811+-0.9807        ? might be 1.0624x slower
   string-repeat-arith                               27.6097+-0.5811           27.2865+-1.0052          might be 1.0118x faster
   string-sub                                        59.5830+-4.5310           55.0962+-2.2548          might be 1.0814x faster
   string-test                                        2.6607+-0.0699     ?      2.6846+-0.0984        ?
   string-var-equality                               26.9023+-1.2809           26.8898+-1.6893        
   structure-hoist-over-transitions                   2.4460+-0.1960     ?      2.4542+-0.1483        ?
   substring-concat-weird                            37.0975+-1.8696     ?     37.9767+-2.6965        ? might be 1.0237x slower
   substring-concat                                  38.9295+-1.0435     ?     40.2652+-3.5428        ? might be 1.0343x slower
   substring                                         46.7250+-1.4061           46.1477+-2.4334          might be 1.0125x faster
   switch-char-constant                               2.6931+-0.1853            2.6267+-0.0442          might be 1.0252x faster
   switch-char                                        6.5503+-0.8534            6.1363+-0.7513          might be 1.0675x faster
   switch-constant                                    8.4766+-0.6868            8.3603+-1.4272          might be 1.0139x faster
   switch-string-basic-big-var                       13.5207+-0.4127     ?     13.9292+-0.9656        ? might be 1.0302x slower
   switch-string-basic-big                           13.4317+-1.2721     ?     13.6340+-0.5171        ? might be 1.0151x slower
   switch-string-basic-var                           13.3404+-0.7639     ?     13.9514+-1.0679        ? might be 1.0458x slower
   switch-string-basic                               12.0618+-0.2756     ?     12.3399+-0.2263        ? might be 1.0231x slower
   switch-string-big-length-tower-var                19.5382+-0.8883           19.3960+-0.6414        
   switch-string-length-tower-var                    13.5964+-0.3844     ?     14.3957+-1.6032        ? might be 1.0588x slower
   switch-string-length-tower                        12.3685+-0.3465           12.3418+-1.0001        
   switch-string-short                               12.0588+-0.2471           11.8566+-0.2656          might be 1.0171x faster
   switch                                            13.0385+-1.6912           12.7917+-1.3384          might be 1.0193x faster
   tear-off-arguments-simple                          3.1045+-0.1385     ?      3.1536+-0.3092        ? might be 1.0158x slower
   tear-off-arguments                                 4.5518+-0.4994            4.4827+-0.5349          might be 1.0154x faster
   temporal-structure                                12.5994+-0.3181     ?     12.9323+-0.9252        ? might be 1.0264x slower
   to-int32-boolean                                  13.2832+-0.5729     ?     13.4223+-0.4928        ? might be 1.0105x slower
   try-catch-get-by-val-cloned-arguments             13.7481+-0.6119     ?     14.4667+-0.6819        ? might be 1.0523x slower
   try-catch-get-by-val-direct-arguments              6.3370+-0.9073            6.0754+-0.2570          might be 1.0431x faster
   try-catch-get-by-val-scoped-arguments              7.4062+-0.3904            7.3315+-0.7334          might be 1.0102x faster
   undefined-property-access                        235.4623+-6.2249     ?    236.4904+-8.8459        ?
   undefined-test                                     2.8496+-0.1264     ?      3.0185+-0.2179        ? might be 1.0593x slower
   unprofiled-licm                                   15.3687+-0.9217           15.0091+-0.7997          might be 1.0240x faster
   varargs-call                                      14.4001+-0.1857     ?     14.6958+-0.2039        ? might be 1.0205x slower
   varargs-construct-inline                          19.7086+-1.6777           19.4824+-1.6487          might be 1.0116x faster
   varargs-construct                                 32.7043+-2.3200           31.8022+-1.8111          might be 1.0284x faster
   varargs-inline                                     8.7878+-0.2908     ?      9.1469+-1.0000        ? might be 1.0409x slower
   varargs-strict-mode                                9.8503+-0.4560            9.6945+-0.3129          might be 1.0161x faster
   varargs                                            9.5750+-0.1729     ?      9.7299+-0.5440        ? might be 1.0162x slower
   weird-inlining-const-prop                          2.0314+-0.2221     ?      2.3809+-0.4849        ? might be 1.1720x slower

   <geometric>                                        8.0533+-0.0405            8.0521+-0.0274          might be 1.0002x faster

                                                          Conf#1                    Conf#2                                      
AsmBench:
   bigfib.cpp                                       471.7764+-3.5017     ?    487.9275+-12.7784       ? might be 1.0342x slower
   cray.c                                           424.0862+-8.3635     ?    440.9827+-34.3008       ? might be 1.0398x slower
   dry.c                                            462.8022+-18.7109    ?    464.1502+-37.2670       ?
   FloatMM.c                                        754.9574+-23.9107         750.7539+-15.4918       
   gcc-loops.cpp                                   3793.5697+-36.0436    ?   4015.4735+-488.3612      ? might be 1.0585x slower
   n-body.c                                         887.3397+-34.1997    ?    889.0302+-8.3727        ?
   Quicksort.c                                      446.3313+-11.9112         436.6346+-7.8387          might be 1.0222x faster
   stepanov_container.cpp                         10277.3720+-15907.1606     4092.1757+-91.8203         might be 2.5115x faster
   Towers.c                                         256.8579+-4.7076     ?    259.0417+-7.1674        ?

   <geometric>                                      820.3285+-92.5167         792.0148+-9.7260          might be 1.0357x faster

                                                          Conf#1                    Conf#2                                      
CompressionBench:
   huffman                                          321.3388+-5.9491     ?    323.2857+-12.3924       ?
   arithmetic-simple                                371.3127+-7.7131     ?    382.4933+-30.4509       ? might be 1.0301x slower
   arithmetic-precise                               288.2277+-1.7735     ?    293.5511+-7.8305        ? might be 1.0185x slower
   arithmetic-complex-precise                       284.7605+-6.0316     ?    290.5964+-7.4715        ? might be 1.0205x slower
   arithmetic-precise-order-0                       394.0160+-8.3638          387.5076+-6.2389          might be 1.0168x faster
   arithmetic-precise-order-1                       316.5880+-6.3783     ?    320.7105+-8.6065        ? might be 1.0130x slower
   arithmetic-precise-order-2                       367.7725+-9.4551          367.7529+-10.7545       
   arithmetic-simple-order-1                        363.1527+-8.8705          359.3105+-8.9938          might be 1.0107x faster
   arithmetic-simple-order-2                        423.5934+-10.9974         411.1817+-14.4727         might be 1.0302x faster
   lz-string                                        358.4060+-8.6524     ?    358.7869+-12.2153       ?

   <geometric>                                      346.1999+-2.7604     ?    347.1796+-4.7292        ? might be 1.0028x slower

                                                          Conf#1                    Conf#2                                      
Geomean of preferred means:
   <scaled-result>                                   61.2170+-0.6778     ^     60.3380+-0.1998        ^ definitely 1.0146x faster

[Basile Clement]

Reran AsmBench due to huge hiccup.

Benchmark report for AsmBench on Basiles-MacBook-Pro (MacBookPro11,3).

VMs tested:
"Conf#1" at /Volumes/Data/SVN/Baseline/OpenSource/WebKitBuild/Release/jsc (r183123)
"Conf#2" at /Volumes/Data/SVN/WIP/OpenSource/WebKitBuild/Release/jsc (r183123)

Collected 6 samples per benchmark/VM, with 6 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.

                                  Conf#1                    Conf#2                                      

bigfib.cpp                  472.8986+-3.8969     ?    478.9491+-6.4586        ? might be 1.0128x slower
cray.c                      424.3024+-9.7129          422.5944+-14.4131       
dry.c                       456.4883+-23.2965    ?    465.4514+-15.5756       ? might be 1.0196x slower
FloatMM.c                   752.8911+-12.8045    ?    757.6528+-17.3431       ?
gcc-loops.cpp              3787.7625+-63.5631    ?   3802.5506+-37.2358       ?
n-body.c                    895.4360+-15.5858    ?    905.3407+-30.6225       ? might be 1.0111x slower
Quicksort.c                 437.3180+-9.9509     ?    444.9053+-8.9211        ? might be 1.0173x slower
stepanov_container.cpp     4103.7755+-78.1070        4065.5324+-67.4782       
Towers.c                    259.8154+-8.6392          251.0401+-4.2857          might be 1.0350x faster

<geometric>                 781.6373+-12.5174    ?    783.5936+-6.2165        ? might be 1.0025x slower

[Basile Clement]

Created attachment 251361 [details]
Patch w/ ChangeLog

[Basile Clement]

Created attachment 251478 [details]
Also ObjectAllocationProfile::isNull to private scope

The previous benchmarking issues were apparently present for unrelated reasons.
I am getting weird results:

Basiles-MacBook-Pro:OpenSource elarnon$ JSC_useFTLJIT1=true /Volumes/Data/SVN/Baseline/Internal/Tools/Scripts/run-jsc-benchmarks /Volumes/Data/SVN/Baseline/OpenSource/WebKitBuild/Release/jsc --outer 6 --kraken --benchmark astar
32/32                                        
Generating benchmark report at /Volumes/Data/SVN/Baseline/OpenSource/Kraken_Basiles-MacBook-Pro_20150423_1135_report.txt
And raw data at /Volumes/Data/SVN/Baseline/OpenSource/Kraken_Basiles-MacBook-Pro_20150423_1135.json

Benchmark report for Kraken on Basiles-MacBook-Pro (MacBookPro11,3).

VMs tested:
"Conf#1" at /Volumes/Data/SVN/Baseline/OpenSource/WebKitBuild/Release/jsc (r183152)

Collected 6 samples per benchmark/VM, with 6 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.

                          Conf#1            

ai-astar             424.889+-7.874     

<arithmetic>         424.889+-7.874     


(note the useFTLJIT1=true, so the option has no effect, just triggers the parsing code) VS

Basiles-MacBook-Pro:OpenSource elarnon$ /Volumes/Data/SVN/Baseline/Internal/Tools/Scripts/run-jsc-benchmarks /Volumes/Data/SVN/Baseline/OpenSource/WebKitBuild/Release/jsc --outer 6 --kraken --benchmark astar
32/32                                        
Generating benchmark report at /Volumes/Data/SVN/Baseline/OpenSource/Kraken_Basiles-MacBook-Pro_20150423_1132_report.txt
And raw data at /Volumes/Data/SVN/Baseline/OpenSource/Kraken_Basiles-MacBook-Pro_20150423_1132.json

Benchmark report for Kraken on Basiles-MacBook-Pro (MacBookPro11,3).

VMs tested:
"Conf#1" at /Volumes/Data/SVN/Baseline/OpenSource/WebKitBuild/Release/jsc (r183152)

Collected 6 samples per benchmark/VM, with 6 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.

                          Conf#1            

ai-astar             591.127+-5.260     

<arithmetic>         591.127+-5.260     

Note that this is on the *Baseline*, i.e. w/o patches applied (actually the timings are similar w/ the patch applied but reversed, i.e. around 600 w/ options and around 420 w/ no options).
I discussed this with mlam, who thinks this might be memory alignment issues, which are in any case not related to this patch.

I have also run tests for Kraken/ai-astar (which was the only test w/ significant difference) against r183069 :

Benchmark report for Kraken on Basiles-MacBook-Pro (MacBookPro11,3).

VMs tested:
"Conf#1" at /Volumes/Data/BenchTest/ICloudFix/OpenSource/WebKitBuild/Release/jsc
"Conf#2" at /Volumes/Data/BenchTest/RemoveNode/OpenSource/WebKitBuild/Release/jsc
"Conf#3" at /Volumes/Data/BenchTest/NoDeallocate/OpenSource/WebKitBuild/Release/jsc

Collected 6 samples per benchmark/VM, with 6 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.

                          Conf#1                    Conf#2                    Conf#3                 Conf#3 v. Conf#1     

ai-astar             399.571+-4.196      ?     400.163+-3.402            399.722+-4.901         ?

<arithmetic>         399.571+-4.196      ?     400.163+-3.402            399.722+-4.901         ? might be 1.0004x slower

(Conf#1 is r183069, Conf#2 is r183069 + https://bugs.webkit.org/show_bug.cgi?id=143999, and Conf#3 is Conf#2 + https://bugs.webkit.org/show_bug.cgi?id=144000 + this patch).

So I think this can safely be considered perf-neutral.

[Basile Clement]

Created attachment 251483 [details]
Too many different working directories are bad for your health

[Geoffrey Garen]

Comment on attachment 251483 [details]
Too many different working directories are bad for your health

View in context: https://bugs.webkit.org/attachment.cgi?id=251483&action=review

> Source/JavaScriptCore/runtime/JSFunction.h:127
> +        FunctionRareData* rareData = m_rareData.get();
>  
> -        return m_rareData.get()->allocationStructure();
> +        // The JS thread may be concurrently creating the rare data
> +        // If we see it, we want to ensure it has been properly created
> +        WTF::loadLoadFence();

Sometimes, we load this pointer in JIT code. Does our JIT code need to include a load-load fence?

[Basile Clement]

Comment on attachment 251483 [details]
Too many different working directories are bad for your health

View in context: https://bugs.webkit.org/attachment.cgi?id=251483&action=review

>> Source/JavaScriptCore/runtime/JSFunction.h:127
>> +        WTF::loadLoadFence();
> 
> Sometimes, we load this pointer in JIT code. Does our JIT code need to include a load-load fence?

The load-load fence is only needed if there is possibly a concurrent thread writing to that pointer. 
The only thread writing to the pointer being the JS thread, which is also the only thread running the JIT code (as far as I understand), no fence should be needed.

[WebKit Commit Bot]

Comment on attachment 251483 [details]
Too many different working directories are bad for your health

Clearing flags on attachment: 251483

Committed r183212: <http://trac.webkit.org/changeset/183212>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.