Closed Bug 554535 Opened 15 years ago Closed 15 years ago

JM: Measure per-site property access variation

Categories

(Core :: JavaScript Engine, defect)

Product:
Core
Component:
JavaScript Engine
Type:
defect
Priority:
Not set
Severity:
normal

Tracking

()

Status:
RESOLVED FIXED

People

(Reporter: dmandelin, Assigned: dmandelin)

References

Details

Basically, what we need to know is how much flexibility is required at each PIC site for GETPROP.
Here are the |length| usages in SS:

--------+--------+----------+
| pc        | op   | key    | base   | count(*) |
+-----------+------+--------+--------+----------+
| 0x128ce76 | p    | length | object |     1000 |
| 0x128d1c6 | p    | length | object |      500 |
| 0x128d776 | p    | length | object |      500 |
| 0x128e004 | l    | length | string |       24 |
| 0x128e016 | l    | length | string |        2 |
| 0x128efb7 | l    | length | array  |    63000 |
| 0x128efd1 | l    | length | array  |     1880 |
| 0x128f087 | l    | length | array  |    63000 |
| 0x128f0a1 | l    | length | array  |     1880 |
| 0x129050c | l    | length | string |     6772 |
| 0x129050c | p    | length | object |    20000 |
| 0x1292167 | l    | length | string |    23334 |
| 0x12921ac | l    | length | string |     4878 |
| 0x1292a5c | l    | length | string |    32774 |
| 0x1292c93 | l    | length | array  |      934 |
| 0x1292cf2 | l    | length | array  |    56934 |
| 0x1292d11 | l    | length | array  |      934 |
| 0x129c8f8 | l    | length | string |        1 |
| 0x129d708 | l    | length | string |        1 |
| 0x129d7cb | l    | length | string |    15825 |
| 0x129da34 | l    | length | array  |       17 |
| 0x129e268 | l    | length | array  |   227500 |
| 0x129ea32 | l    | length | string |    10065 |
| 0x129ec5a | l    | length | array  |       21 |
| 0x30c09a  | l    | length | array  |       27 |
| 0x30c0a9  | l    | length | string |        1 |
| 0x30c1c3  | l    | length | array  |        1 |
| 0x30c247  | l    | length | array  |       27 |
| 0x3104fe  | l    | length | array  |    17084 |
| 0x311d98  | l    | length | array  |        4 |
| 0x31231a  | l    | length | array  |        8 |
| 0x81de39  | l    | length | array  |      159 |
| 0x81e04e  | l    | length | array  |        4 |
| 0x821c75  | l    | length | array  |     4500 |
| 0x82485a  | l    | length | array  |      170 |
| 0x825749  | l    | length | array  |      249 |
| 0x831cf8  | l    | length | array  |    20295 |
| 0x831eb4  | l    | length | array  |     1760 |
| 0x83d8b2  | l    | length | string |      448 |
| 0x83e3b7  | l    | length | string |        1 |
| 0x83e462  | l    | length | string |        1 |
| 0x843d8b  | l    | length | array  |        1 |
| 0x843e85  | l    | length | string |     1427 |
| 0x843ea1  | l    | length | array  |       85 |
| 0x844dc8  | l    | length | string |    28000 |
| 0x844dd6  | l    | length | string |     2000 |
| 0x8456e5  | l    | length | array  |       28 |
| 0x845a4f  | l    | length | string |        2 |
| 0x845bd7  | l    | length | string |        1 |
| 0x845bf3  | l    | length | string |        1 |
| 0x845c30  | l    | length | array  |        9 |
| 0x84df04  | l    | length | string |    29589 |
| 0x84df99  | l    | length | array  |     2501 |
+-----------+------+--------+--------+----------+

Note that at each site, either the base (|o| in |o.length|) is an array always, an object always, or a string always, not mixtures. Here are the totals:

+--------+----------+
| base   | count(*) |
+--------+----------+
| array  |   463012 |
| object |    22000 |
| string |   155147 |
+--------+----------+

The array optimization looks more important.
Another key point about the above is that in SS, JSOP_LENGTH always gets an array or an string, never an object.
(SunSpider) Here are the non-fast-path GETELEM accesses:

+-----------+-------+--------+-------+----------+
| pc        | key   | base   | shape | count(*) |
+-----------+-------+--------+-------+----------+
| 0x128ddaa | Y-m-d | object |  3823 |     8000 |
| 0x128ddc7 | Y-m-d | object |  3887 |     8000 |
| 0x1292307 | c     | object |  4045 |       17 |
| 0x129230e | a     | object |  4045 |       17 |
| 0x1292cd0 | a     | object |  4045 |   175116 |
| 0x12934d5 | tag   | object |  4092 |     5000 |
| 0x1294977 | d     | object |  9017 |     9726 |
| 0x30e687  | if    | object |  8415 |    24180 |
| 0x3126a7  | if    | object |  6084 |    32974 |
| 0x312757  | G     | object |  6702 |    14586 |
| 0x845c5b  | B     | object |  3966 |       11 |
+-----------+-------+--------+-------+----------+

It looks like a PIC could be useful even here, given that the prop names don't seem to change.
(SunSpider) GETPROP accesses. It seems there is only one shape per site--it's hard for me to believe that, but maybe it's true.

+-----------+-------+--------+----------+
| pc        | shape | base   | count(*) |
+-----------+-------+--------+----------+
| 0x128ce76 |   293 | object |     1000 |
| 0x128d1c6 |   293 | object |      500 |
| 0x128d776 |   293 | object |      500 |
| 0x128d95c |   218 | object |     1000 |
| 0x128dc85 |   217 | object |        1 |
| 0x128dda4 |  3884 | object |     8000 |
| 0x128ddc1 |  3885 | object |     8000 |
| 0x128df4f |  3885 | object |        2 |
| 0x128df5d |  3885 | object |        2 |
| 0x129050c |   293 | object |    20000 |
| 0x1290e98 |  3885 | object |        1 |
| 0x12915f8 |  3885 | object |        1 |
| 0x12916e0 |  3885 | object |     4000 |
| 0x12916f5 |  3885 | object |     4000 |
| 0x12934b1 |    39 | object |    10001 |
| 0x12934b4 |  4086 | object |    10001 |
| 0x1293d99 |  4092 | object |    26617 |
| 0x1293d9e |  4092 | object |    26617 |
| 0x1293dad |  4092 | object |    13059 |
| 0x1293db2 |  4092 | object |    13059 |
| 0x1293ea3 |    39 | object |        1 |
| 0x1293ea6 |   653 | object |        1 |
| 0x1293eb0 |   148 | object |        1 |
| 0x1293ebd |    17 | object |        1 |
| 0x1293eca |  3885 | object |        1 |
| 0x1293ed7 |   578 | object |        1 |
| 0x1293ee4 |    39 | object |        1 |
| 0x1293ef5 |  3855 | object |        1 |
| 0x1294581 |  9045 | object |    12000 |
| 0x30df16  |   411 | object |      204 |
| 0x30e036  |   411 | object |      204 |
| 0x30e156  |   411 | object |      204 |
| 0x30e71c  |   411 | object |       15 |
| 0x30e72d  |   411 | object |       15 |
| 0x30e73f  |   411 | object |       15 |
| 0x30e9fc  |   430 | object |      120 |
| 0x30ff4d  |   495 | object |    35000 |
| 0x30ff59  |   495 | object |    35000 |
| 0x30ff69  |   495 | object |    35000 |
| 0x30ff6d  |   495 | object |    35000 |
| 0x30ff79  |   495 | object |    35000 |
| 0x30ff89  |   495 | object |    35000 |
| 0x30ff8f  |   495 | object |    35000 |
| 0x30ff94  |   495 | object |    35000 |
| 0x30ffa0  |   495 | object |    35000 |
| 0x30ffdd  |   495 | object |    23336 |
| 0x30fff8  |   495 | object |    23336 |
| 0x310003  |   495 | object |    23336 |
| 0x31000a  |   495 | object |    23336 |
| 0x310020  |   500 | object |    14041 |
| 0x310027  |   500 | object |    14041 |
| 0x3104ad  |   505 | object |    16058 |
| 0x3104fb  |   505 | object |    17084 |
| 0x310686  |   513 | object |       30 |
| 0x310692  |   513 | object |       30 |
| 0x3106a4  |   513 | object |       30 |
| 0x3106b3  |   513 | object |       30 |
| 0x3106d5  |   513 | object |       30 |
| 0x3106e4  |   513 | object |       30 |
| 0x310aa0  |   517 | object |      900 |
| 0x310ab2  |   517 | object |      900 |
| 0x310ad4  |   517 | object |      900 |
| 0x310ae6  |   517 | object |      900 |
| 0x311055  |   546 | object |    42072 |
| 0x31105d  |   546 | object |    21440 |
| 0x311064  |   546 | object |    20632 |
| 0x311068  |   546 | object |    20632 |
| 0x311074  |   546 | object |    20632 |
| 0x311d95  |   618 | object |        4 |
| 0x311da6  |   618 | object |       20 |
| 0x311db1  |   616 | object |       20 |
| 0x311dbd  |   616 | object |       20 |
| 0x311dce  |   616 | object |       20 |
| 0x311ddf  |   616 | object |       20 |
| 0x311dfb  |   618 | object |        4 |
| 0x312317  |   618 | object |        8 |
| 0x312328  |   618 | object |       40 |
| 0x312339  |   616 | object |       40 |
| 0x31233f  |   616 | object |       40 |
| 0x312344  |   616 | object |       40 |
| 0x31234a  |   616 | object |       40 |
| 0x31234f  |   616 | object |       40 |
| 0x312356  |   616 | object |       40 |
| 0x31235b  |   616 | object |       40 |
| 0x312375  |   618 | object |       80 |
| 0x312380  |   616 | object |       80 |
| 0x312385  |   616 | object |       80 |
| 0x31238f  |   616 | object |       80 |
| 0x312394  |   616 | object |       80 |
| 0x31239e  |   616 | object |       80 |
| 0x3123a3  |   616 | object |       80 |
| 0x3123d5  |   616 | object |       80 |
| 0x3123da  |   616 | object |       80 |
| 0x312691  |    10 | object |        1 |
| 0x3126a4  |    10 | object |        1 |
| 0x3126b1  |   357 | object |        1 |
| 0x818c4d  |   360 | object |     1852 |
| 0x818c58  |   360 | object |     1852 |
| 0x818c63  |   360 | object |     1852 |
| 0x818c6e  |   360 | object |     1852 |
| 0x818d7f  |   416 | array  |     1852 |
| 0x818d91  |   416 | array  |     1852 |
| 0x81c4b1  |    10 | object |        1 |
| 0x821c72  |   618 | object |     4500 |
| 0x821c83  |   618 | object |    22500 |
| 0x821c9b  |   618 | object |    45000 |
| 0x821ca6  |   616 | object |    45000 |
| 0x821cab  |   616 | object |    45000 |
| 0x821cb5  |   616 | object |    45000 |
| 0x821cba  |   616 | object |    45000 |
| 0x821cc4  |   616 | object |    45000 |
| 0x821cc9  |   616 | object |    45000 |
| 0x821d0f  |   616 | object |    45000 |
| 0x821d15  |   616 | object |    45000 |
| 0x821d28  |   616 | object |    45000 |
| 0x821d2e  |   616 | object |    45000 |
| 0x821d41  |   616 | object |    45000 |
| 0x821d47  |   616 | object |    45000 |
| 0x821d5a  |   616 | object |    45000 |
| 0x821d60  |   616 | object |    45000 |
| 0x821d73  |   616 | object |    45000 |
| 0x821d79  |   616 | object |    45000 |
| 0x821d8c  |   616 | object |    45000 |
| 0x821d92  |   616 | object |    45000 |
| 0x821dc6  |   618 | object |    22500 |
| 0x821dd5  |   616 | object |    22500 |
| 0x821ddb  |   616 | object |    22500 |
| 0x821dea  |   616 | object |    22500 |
| 0x821df0  |   616 | object |    22500 |
| 0x821dff  |   616 | object |    22500 |
| 0x821e05  |   616 | object |    22500 |
| 0x82a417  |  3826 | object |        1 |
| 0x82a456  |  3833 | object |        1 |
| 0x82a463  |  3833 | object |        1 |
| 0x82a470  |  3833 | object |        1 |
| 0x82a47d  |  3833 | object |        1 |
| 0x82a48a  |  3833 | object |        1 |
| 0x82a497  |  3833 | object |        1 |
| 0x82a4a4  |  3833 | object |        1 |
| 0x82a4b1  |  3833 | object |        1 |
| 0x82a4be  |  3833 | object |        1 |
| 0x82ad3f  |   484 | object |       14 |
| 0x82ad4b  |   484 | object |       14 |
| 0x82ad9e  |   485 | object |       14 |
| 0x82adb2  |   486 | object |       14 |
| 0x82adcc  |   487 | object |       14 |
| 0x82f942  |  3931 | object |    31744 |
| 0x82f95e  |  3931 | object |    31744 |
| 0x82f975  |  3931 | object |    31744 |
| 0x82f98e  |  3931 | object |    31744 |
| 0x82f9a7  |  3931 | object |    31744 |
| 0x82f9b8  |  3931 | object |    31744 |
| 0x82f9c9  |  3931 | object |    31744 |
| 0x82f9dc  |  3931 | object |    31744 |
| 0x831c9b  |   505 | object |    18942 |
| 0x831cf5  |   505 | object |    20295 |
| 0x831d04  |   505 | object |      460 |
| 0x831d09  |   505 | object |      460 |
| 0x831d0e  |   505 | object |      460 |
| 0x831d18  |   500 | object |      893 |
| 0x831d6d  |   500 | object |      893 |
| 0x831d8f  |   495 | object |       98 |
| 0x831d9d  |    -1 | array  |      893 |
| 0x831dea  |   499 | array  |      453 |
| 0x831dfa  |   505 | object |      440 |
| 0x831dff  |   505 | object |      440 |
| 0x831e04  |   505 | object |      440 |
| 0x831e1a  |   505 | object |     1320 |
| 0x831e98  |   506 | array  |     1019 |
| 0x831eb1  |   505 | object |     1760 |
| 0x838169  |   513 | object |        1 |
| 0x838180  |   513 | object |        1 |
| 0x838197  |   513 | object |        1 |
| 0x8381af  |   513 | object |        1 |
| 0x8381c7  |   513 | object |        1 |
| 0x8381d1  |   513 | object |        1 |
| 0x8381dc  |   513 | object |        1 |
| 0x8381e6  |   513 | object |        1 |
| 0x8381f1  |   513 | object |        1 |
| 0x8381fc  |   513 | object |        1 |
| 0x838208  |   513 | object |        1 |
| 0x838213  |   513 | object |        1 |
| 0x83a082  |   416 | array  |     1248 |
| 0x83a161  |   416 | array  |      100 |
| 0x83a182  |   416 | array  |      100 |
| 0x83a18d  |   416 | array  |      100 |
| 0x83a1ae  |   416 | array  |      100 |
| 0x83a1b9  |   416 | array  |      100 |
| 0x83a1da  |   416 | array  |      100 |
| 0x83a1e5  |   416 | array  |      100 |
| 0x83a206  |   416 | array  |      100 |
| 0x83a21f  |   416 | array  |      208 |
| 0x83a240  |   416 | array  |      208 |
| 0x83a24b  |   416 | array  |      208 |
| 0x83a26c  |   416 | array  |      208 |
| 0x83a277  |   416 | array  |      208 |
| 0x83a298  |   416 | array  |      108 |
| 0x83a2a3  |   416 | array  |      208 |
| 0x83a2c4  |   416 | array  |      208 |
| 0x83a2dd  |   416 | array  |      104 |
| 0x83a309  |   416 | array  |      104 |
| 0x83a329  |   416 | array  |      104 |
| 0x83a334  |   416 | array  |      104 |
| 0x83a352  |   416 | array  |      104 |
| 0x83a35c  |   416 | array  |      104 |
| 0x83a37c  |   416 | array  |      104 |
| 0x83a395  |   416 | array  |      204 |
| 0x83a3b5  |   416 | array  |      100 |
| 0x83a3c0  |   416 | array  |      204 |
| 0x83a3e0  |   416 | array  |      204 |
| 0x83a3eb  |   416 | array  |      204 |
| 0x83a40c  |   416 | array  |      104 |
| 0x83a417  |   416 | array  |      204 |
| 0x83d880  |   356 | object |      208 |
| 0x83d886  |   356 | object |      208 |
| 0x83d895  |   356 | object |      204 |
| 0x83d8c8  |   360 | object |      204 |
| 0x83d8d4  |   360 | object |      204 |
| 0x83d8e0  |   360 | object |      204 |
| 0x83d936  |   360 | object |      204 |
| 0x83d941  |   360 | object |      204 |
| 0x83d94c  |   360 | object |      204 |
| 0x83d98d  |   360 | object |     1836 |
| 0x84568f  |   371 | array  |       24 |
| 0x84569e  |   371 | array  |       24 |
| 0x8456a8  |   360 | object |       24 |
| 0x8456b1  |   371 | array  |       24 |
| 0x8456bb  |   360 | object |       24 |
| 0x8456c4  |   371 | array  |       24 |
| 0x8456cf  |   360 | object |       24 |
| 0x8456e2  |   371 | array  |       28 |
| 0x84572e  |   413 | array  |     5404 |
| 0x845741  |   348 | object |        4 |
| 0x845749  |   348 | object |        4 |
| 0x845751  |   348 | object |        4 |
| 0x845791  |   360 | object |       36 |
| 0x845c12  |   673 | object |        9 |
| 0x84a53a  |   505 | object |        1 |
| 0x84a54f  |   505 | object |        1 |
| 0x84a56a  |   505 | object |        1 |
| 0x84a57f  |   505 | object |        1 |
| 0x84a59a  |   505 | object |        1 |
| 0x84a5b0  |   505 | object |        1 |
| 0x84bf36  |    10 | object |        1 |
| 0x84bf52  |    10 | object |        1 |
| 0x84bf5f  |   357 | object |        1 |
| 0x84bf6d  |    10 | object |        1 |
| 0x84bf7b  |   357 | object |        1 |
| 0x84deba  |  4092 | object |     2500 |
| 0x84df39  |  4092 | object |     2500 |
+-----------+-------+--------+----------+
(SunSpider) GETPROP. This supersedes comment 4. I noticed a bug in my SQL.

+-----------+-------+--------+-----------------+----------+
| pc        | shape | base   | key             | count(*) |
+-----------+-------+--------+-----------------+----------+
| 0x128ce76 |   293 | object | length          |     1000 |
| 0x128d1c6 |   293 | object | length          |      500 |
| 0x128d776 |   293 | object | length          |      500 |
| 0x128d95c |   218 | object | getFullYear     |     1000 |
| 0x128dc85 |   217 | object | prototype       |        1 |
| 0x128dda4 |  3884 | object | formatFunctions |        1 |
| 0x128dda4 |  3885 | object | formatFunctions |     7999 |
| 0x128ddc1 |  3885 | object | formatFunctions |     8000 |
| 0x128df4f |  3885 | object | formatFunctions |        2 |
| 0x128df5d |  3885 | object | formatFunctions |        2 |
| 0x129050c |   293 | object | length          |    20000 |
| 0x1290e98 |  3885 | object | prototype       |        1 |
| 0x12915f8 |  3885 | object | prototype       |        1 |
| 0x12916e0 |  3885 | object | dayNames        |     4000 |
| 0x12916f5 |  3885 | object | monthNames      |     4000 |
| 0x12934b1 |    39 | object | prototype       |    10001 |
| 0x12934b4 |  4086 | object | hasOwnProperty  |    10001 |
| 0x1293d99 |  4092 | object | tag             |    26617 |
| 0x1293d9e |  4092 | object | tag             |    26617 |
| 0x1293dad |  4092 | object | tag             |    13059 |
| 0x1293db2 |  4092 | object | tag             |    13059 |
| 0x1293ea3 |    39 | object | prototype       |        1 |
| 0x1293ea6 |   653 | object | toJSONString    |        1 |
| 0x1293eb0 |   148 | object | prototype       |        1 |
| 0x1293ebd |    17 | object | prototype       |        1 |
| 0x1293eca |  3885 | object | prototype       |        1 |
| 0x1293ed7 |   578 | object | prototype       |        1 |
| 0x1293ee4 |    39 | object | prototype       |        1 |
| 0x1293ef5 |  3855 | object | prototype       |        1 |
| 0x1294581 |  9045 | object | endResult       |    12000 |
| 0x30df16  |   411 | object | PI              |      204 |
| 0x30e036  |   411 | object | PI              |      204 |
| 0x30e156  |   411 | object | PI              |      204 |
| 0x30e71c  |   411 | object | PI              |       15 |
| 0x30e72d  |   411 | object | sin             |       15 |
| 0x30e73f  |   411 | object | PI              |       15 |
| 0x30e9fc  |   430 | object | testOutput      |      120 |
| 0x30ff4d  |   495 | object | axis            |    30242 |
| 0x30ff4d  |   500 | object | axis            |       45 |
| 0x30ff4d  |   518 | object | axis            |     2378 |
| 0x30ff4d  |   519 | object | axis            |     2335 |
| 0x30ff59  |   495 | object | axis            |    30242 |
| 0x30ff59  |   500 | object | axis            |       45 |
| 0x30ff59  |   518 | object | axis            |     2378 |
| 0x30ff59  |   519 | object | axis            |     2335 |
| 0x30ff69  |   495 | object | axis            |    30242 |
| 0x30ff69  |   500 | object | axis            |       45 |
| 0x30ff69  |   518 | object | axis            |     2378 |
| 0x30ff69  |   519 | object | axis            |     2335 |
| 0x30ff6d  |   495 | object | nu              |    30242 |
| 0x30ff6d  |   500 | object | nu              |       45 |
| 0x30ff6d  |   518 | object | nu              |     2378 |
| 0x30ff6d  |   519 | object | nu              |     2335 |
| 0x30ff79  |   495 | object | nv              |    30242 |
| 0x30ff79  |   500 | object | nv              |       45 |
| 0x30ff79  |   518 | object | nv              |     2378 |
| 0x30ff79  |   519 | object | nv              |     2335 |
| 0x30ff89  |   495 | object | nd              |    30242 |
| 0x30ff89  |   500 | object | nd              |       45 |
| 0x30ff89  |   518 | object | nd              |     2378 |
| 0x30ff89  |   519 | object | nd              |     2335 |
| 0x30ff8f  |   495 | object | axis            |    30242 |
| 0x30ff8f  |   500 | object | axis            |       45 |
| 0x30ff8f  |   518 | object | axis            |     2378 |
| 0x30ff8f  |   519 | object | axis            |     2335 |
| 0x30ff94  |   495 | object | nu              |    30242 |
| 0x30ff94  |   500 | object | nu              |       45 |
| 0x30ff94  |   518 | object | nu              |     2378 |
| 0x30ff94  |   519 | object | nu              |     2335 |
| 0x30ffa0  |   495 | object | nv              |    30242 |
| 0x30ffa0  |   500 | object | nv              |       45 |
| 0x30ffa0  |   518 | object | nv              |     2378 |
| 0x30ffa0  |   519 | object | nv              |     2335 |
| 0x30ffdd  |   495 | object | eu              |    21672 |
| 0x30ffdd  |   500 | object | eu              |       18 |
| 0x30ffdd  |   518 | object | eu              |      831 |
| 0x30ffdd  |   519 | object | eu              |      815 |
| 0x30fff8  |   495 | object | ev              |    21672 |
| 0x30fff8  |   500 | object | ev              |       18 |
| 0x30fff8  |   518 | object | ev              |      831 |
| 0x30fff8  |   519 | object | ev              |      815 |
| 0x310003  |   495 | object | nu1             |    21672 |
| 0x310003  |   500 | object | nu1             |       18 |
| 0x310003  |   518 | object | nu1             |      831 |
| 0x310003  |   519 | object | nu1             |      815 |
| 0x31000a  |   495 | object | nv1             |    21672 |
| 0x31000a  |   500 | object | nv1             |       18 |
| 0x31000a  |   518 | object | nv1             |      831 |
| 0x31000a  |   519 | object | nv1             |      815 |
| 0x310020  |   495 | object | nu2             |    12798 |
| 0x310020  |   500 | object | nu2             |        3 |
| 0x310020  |   518 | object | nu2             |      831 |
| 0x310020  |   519 | object | nu2             |      409 |
| 0x310027  |   495 | object | nv2             |    12798 |
| 0x310027  |   500 | object | nv2             |        3 |
| 0x310027  |   518 | object | nv2             |      831 |
| 0x310027  |   519 | object | nv2             |      409 |
| 0x3104ad  |   505 | object | triangles       |    16058 |
| 0x3104fb  |   505 | object | triangles       |    17084 |
| 0x310686  |   513 | object | origin          |       30 |
| 0x310692  |   513 | object | origin          |       30 |
| 0x3106a4  |   513 | object | directions      |       30 |
| 0x3106b3  |   513 | object | directions      |       30 |
| 0x3106d5  |   513 | object | directions      |       30 |
| 0x3106e4  |   513 | object | directions      |       30 |
| 0x310aa0  |   517 | object | origin          |      900 |
| 0x310ab2  |   517 | object | origin          |      900 |
| 0x310ad4  |   517 | object | dir             |      900 |
| 0x310ae6  |   517 | object | dir             |      900 |
| 0x311055  |   546 | object | left            |    42072 |
| 0x31105d  |   546 | object | item            |    21440 |
| 0x311064  |   546 | object | item            |    20632 |
| 0x311068  |   546 | object | left            |    20632 |
| 0x311074  |   546 | object | right           |    20632 |
| 0x311d95  |   618 | object | bodies          |        4 |
| 0x311da6  |   618 | object | bodies          |       20 |
| 0x311db1  |   616 | object | mass            |       20 |
| 0x311dbd  |   616 | object | vx              |       20 |
| 0x311dce  |   616 | object | vy              |       20 |
| 0x311ddf  |   616 | object | vz              |       20 |
| 0x311dfb  |   618 | object | bodies          |        4 |
| 0x312317  |   618 | object | bodies          |        8 |
| 0x312328  |   618 | object | bodies          |       40 |
| 0x312339  |   616 | object | mass            |       40 |
| 0x31233f  |   616 | object | vx              |       40 |
| 0x312344  |   616 | object | vx              |       40 |
| 0x31234a  |   616 | object | vy              |       40 |
| 0x31234f  |   616 | object | vy              |       40 |
| 0x312356  |   616 | object | vz              |       40 |
| 0x31235b  |   616 | object | vz              |       40 |
| 0x312375  |   618 | object | bodies          |       80 |
| 0x312380  |   616 | object | x               |       80 |
| 0x312385  |   616 | object | x               |       80 |
| 0x31238f  |   616 | object | y               |       80 |
| 0x312394  |   616 | object | y               |       80 |
| 0x31239e  |   616 | object | z               |       80 |
| 0x3123a3  |   616 | object | z               |       80 |
| 0x3123d5  |   616 | object | mass            |       80 |
| 0x3123da  |   616 | object | mass            |       80 |
| 0x312691  |    10 | object | prototype       |        1 |
| 0x3126a4  |    10 | object | prototype       |        1 |
| 0x3126b1  |   357 | object | prototype       |        1 |
| 0x818c4d  |   360 | object | V               |     1852 |
| 0x818c58  |   360 | object | V               |     1852 |
| 0x818c63  |   360 | object | V               |     1852 |
| 0x818c6e  |   360 | object | V               |     1852 |
| 0x818d7f  |   416 | array  | LastPx          |     1852 |
| 0x818d91  |   416 | array  | LastPx          |     1852 |
| 0x81c4b1  |    10 | object | prototype       |        1 |
| 0x821c72  |   618 | object | bodies          |     4500 |
| 0x821c83  |   618 | object | bodies          |    22500 |
| 0x821c9b  |   618 | object | bodies          |    45000 |
| 0x821ca6  |   616 | object | x               |    45000 |
| 0x821cab  |   616 | object | x               |    45000 |
| 0x821cb5  |   616 | object | y               |    45000 |
| 0x821cba  |   616 | object | y               |    45000 |
| 0x821cc4  |   616 | object | z               |    45000 |
| 0x821cc9  |   616 | object | z               |    45000 |
| 0x821d0f  |   616 | object | vx              |    45000 |
| 0x821d15  |   616 | object | mass            |    45000 |
| 0x821d28  |   616 | object | vy              |    45000 |
| 0x821d2e  |   616 | object | mass            |    45000 |
| 0x821d41  |   616 | object | vz              |    45000 |
| 0x821d47  |   616 | object | mass            |    45000 |
| 0x821d5a  |   616 | object | vx              |    45000 |
| 0x821d60  |   616 | object | mass            |    45000 |
| 0x821d73  |   616 | object | vy              |    45000 |
| 0x821d79  |   616 | object | mass            |    45000 |
| 0x821d8c  |   616 | object | vz              |    45000 |
| 0x821d92  |   616 | object | mass            |    45000 |
| 0x821dc6  |   618 | object | bodies          |    22500 |
| 0x821dd5  |   616 | object | x               |    22500 |
| 0x821ddb  |   616 | object | vx              |    22500 |
| 0x821dea  |   616 | object | y               |    22500 |
| 0x821df0  |   616 | object | vy              |    22500 |
| 0x821dff  |   616 | object | z               |    22500 |
| 0x821e05  |   616 | object | vz              |    22500 |
| 0x82a417  |  3826 | object | prototype       |        1 |
| 0x82a456  |  3833 | object | prototype       |        1 |
| 0x82a463  |  3833 | object | prototype       |        1 |
| 0x82a470  |  3833 | object | prototype       |        1 |
| 0x82a47d  |  3833 | object | prototype       |        1 |
| 0x82a48a  |  3833 | object | prototype       |        1 |
| 0x82a497  |  3833 | object | prototype       |        1 |
| 0x82a4a4  |  3833 | object | prototype       |        1 |
| 0x82a4b1  |  3833 | object | prototype       |        1 |
| 0x82a4be  |  3833 | object | prototype       |        1 |
| 0x82ad3f  |   484 | object | axis            |       14 |
| 0x82ad4b  |   484 | object | axis            |       14 |
| 0x82ad9e  |   485 | object | axis            |       14 |
| 0x82adb2  |   486 | object | axis            |       14 |
| 0x82adcc  |   487 | object | axis            |       14 |
| 0x82f942  |  3931 | object | a2              |    31744 |
| 0x82f95e  |  3931 | object | a3              |    31744 |
| 0x82f975  |  3931 | object | a4              |    31744 |
| 0x82f98e  |  3931 | object | a5              |    31744 |
| 0x82f9a7  |  3931 | object | a6              |    31744 |
| 0x82f9b8  |  3931 | object | a7              |    31744 |
| 0x82f9c9  |  3931 | object | a8              |    31744 |
| 0x82f9dc  |  3931 | object | a9              |    31744 |
| 0x831c9b  |   505 | object | triangles       |    18942 |
| 0x831cf5  |   505 | object | triangles       |    20295 |
| 0x831d04  |   505 | object | background      |      460 |
| 0x831d09  |   505 | object | background      |      460 |
| 0x831d0e  |   505 | object | background      |      460 |
| 0x831d18  |   495 | object | normal          |       98 |
| 0x831d18  |   500 | object | normal          |        2 |
| 0x831d18  |   518 | object | normal          |      420 |
| 0x831d18  |   519 | object | normal          |      373 |
| 0x831d6d  |   495 | object | shader          |       98 |
| 0x831d6d  |   500 | object | shader          |        2 |
| 0x831d6d  |   518 | object | shader          |      420 |
| 0x831d6d  |   519 | object | shader          |      373 |
| 0x831d8f  |   495 | object | material        |       98 |
| 0x831d9d  |    -1 | array  | reflection      |      440 |
| 0x831d9d  |   499 | array  | reflection      |      453 |
| 0x831dea  |   499 | array  | reflection      |      453 |
| 0x831dfa  |   505 | object | ambient         |      440 |
| 0x831dff  |   505 | object | ambient         |      440 |
| 0x831e04  |   505 | object | ambient         |      440 |
| 0x831e1a  |   505 | object | lights          |     1320 |
| 0x831e98  |   506 | array  | colour          |     1019 |
| 0x831eb1  |   505 | object | lights          |     1760 |
| 0x838169  |   513 | object | directions      |        1 |
| 0x838180  |   513 | object | directions      |        1 |
| 0x838197  |   513 | object | directions      |        1 |
| 0x8381af  |   513 | object | directions      |        1 |
| 0x8381c7  |   513 | object | directions      |        1 |
| 0x8381d1  |   513 | object | directions      |        1 |
| 0x8381dc  |   513 | object | directions      |        1 |
| 0x8381e6  |   513 | object | directions      |        1 |
| 0x8381f1  |   513 | object | directions      |        1 |
| 0x8381fc  |   513 | object | directions      |        1 |
| 0x838208  |   513 | object | directions      |        1 |
| 0x838213  |   513 | object | directions      |        1 |
| 0x83a082  |   416 | array  | Normal          |     1248 |
| 0x83a161  |   416 | array  | Line            |      100 |
| 0x83a182  |   416 | array  | Line            |      100 |
| 0x83a18d  |   416 | array  | Line            |      100 |
| 0x83a1ae  |   416 | array  | Line            |      100 |
| 0x83a1b9  |   416 | array  | Line            |      100 |
| 0x83a1da  |   416 | array  | Line            |      100 |
| 0x83a1e5  |   416 | array  | Line            |      100 |
| 0x83a206  |   416 | array  | Line            |      100 |
| 0x83a21f  |   416 | array  | Line            |      208 |
| 0x83a240  |   416 | array  | Line            |      208 |
| 0x83a24b  |   416 | array  | Line            |      208 |
| 0x83a26c  |   416 | array  | Line            |      208 |
| 0x83a277  |   416 | array  | Line            |      208 |
| 0x83a298  |   416 | array  | Line            |      108 |
| 0x83a2a3  |   416 | array  | Line            |      208 |
| 0x83a2c4  |   416 | array  | Line            |      208 |
| 0x83a2dd  |   416 | array  | Line            |      104 |
| 0x83a309  |   416 | array  | Line            |      104 |
| 0x83a329  |   416 | array  | Line            |      104 |
| 0x83a334  |   416 | array  | Line            |      104 |
| 0x83a352  |   416 | array  | Line            |      104 |
| 0x83a35c  |   416 | array  | Line            |      104 |
| 0x83a37c  |   416 | array  | Line            |      104 |
| 0x83a395  |   416 | array  | Line            |      204 |
| 0x83a3b5  |   416 | array  | Line            |      100 |
| 0x83a3c0  |   416 | array  | Line            |      204 |
| 0x83a3e0  |   416 | array  | Line            |      204 |
| 0x83a3eb  |   416 | array  | Line            |      204 |
| 0x83a40c  |   416 | array  | Line            |      104 |
| 0x83a417  |   416 | array  | Line            |      204 |
| 0x83d880  |   356 | object | LoopCount       |      208 |
| 0x83d886  |   356 | object | LoopMax         |      208 |
| 0x83d895  |   356 | object | LoopCount       |      204 |
| 0x83d8c8  |   360 | object | V               |      204 |
| 0x83d8d4  |   360 | object | V               |      204 |
| 0x83d8e0  |   360 | object | V               |      204 |
| 0x83d936  |   360 | object | V               |      204 |
| 0x83d941  |   360 | object | V               |      204 |
| 0x83d94c  |   360 | object | V               |      204 |
| 0x83d98d  |   360 | object | V               |     1836 |
| 0x84568f  |   371 | array  | Normal          |        6 |
| 0x84568f  |   416 | array  | Normal          |       18 |
| 0x84569e  |   371 | array  | Edge            |        6 |
| 0x84569e  |   416 | array  | Edge            |       18 |
| 0x8456a8  |   360 | object | V               |       24 |
| 0x8456b1  |   371 | array  | Edge            |        6 |
| 0x8456b1  |   416 | array  | Edge            |       18 |
| 0x8456bb  |   360 | object | V               |       24 |
| 0x8456c4  |   371 | array  | Edge            |        6 |
| 0x8456c4  |   416 | array  | Edge            |       18 |
| 0x8456cf  |   360 | object | V               |       24 |
| 0x8456e2  |   371 | array  | Edge            |        7 |
| 0x8456e2  |   416 | array  | Edge            |       21 |
| 0x84572e  |   413 | array  | NumPx           |      361 |
| 0x84572e  |   416 | array  | NumPx           |     5043 |
| 0x845741  |   348 | object | V               |        4 |
| 0x845749  |   348 | object | V               |        4 |
| 0x845751  |   348 | object | V               |        4 |
| 0x845791  |   360 | object | V               |       36 |
| 0x845c12  |   673 | object | source          |        9 |
| 0x84a53a  |   505 | object | lights          |        1 |
| 0x84a54f  |   505 | object | lights          |        1 |
| 0x84a56a  |   505 | object | lights          |        1 |
| 0x84a57f  |   505 | object | lights          |        1 |
| 0x84a59a  |   505 | object | lights          |        1 |
| 0x84a5b0  |   505 | object | lights          |        1 |
| 0x84bf36  |    10 | object | prototype       |        1 |
| 0x84bf52  |    10 | object | prototype       |        1 |
| 0x84bf5f  |   357 | object | prototype       |        1 |
| 0x84bf6d  |    10 | object | prototype       |        1 |
| 0x84bf7b  |   357 | object | prototype       |        1 |
| 0x84deba  |  4092 | object | tag             |     2500 |
| 0x84df39  |  4092 | object | popularity      |     2500 |
+-----------+-------+--------+-----------------+----------+
SunSpider, GETPROP, histogram of number of shapes per static GETPROP pc:

+---------+----------+
| nshapes | count(*) |
+---------+----------+
|       1 |      225 |
|       2 |        8 |
|       4 |       17 |
+---------+----------+

SunSpider, GETPROP, histogram of number of dynamic accesses sites with a given number of shapes:

+---------+------------+
| nshapes | sum(natpc) |
+---------+------------+
|       1 |    1680263 |
|       2 |      14421 |
|       4 |     438212 |
+---------+------------+
V8-V4, LENGTH. Here, only the array optimization is probably worthwhile. It kind of makes sense that programs loop over arrays element-by-element much more often than they do strings.

    PC      jsop  base type       dynamic count

0x0020bc2a length   array               8
0x0020bc39 length   string              1
0x0020bd53 length   array               1
0x0020bdd7 length   array               8
0x00213f81 length   array             256
0x0021443c length   array             257
0x0021453f length   array             224
0x002148c7 length   string              8
0x002148ea length   string              8
0x00214ba0 length   string             16
0x00214ba9 length   string             16
0x00214d92 length   string              8
0x00214ea6 length   array               8
0x00214eba length   array               8
0x00214ee5 length   array             112
0x00214f22 length   array             896
0x00215198 length   string             16
0x002151a1 length   string             16
0x00216296 length   array           32705
0x00216d9d length   array         2794185
0x008178fc length   array               8
0x008178fc length   string            136
0x008b47ba length   array               1
0x008ec075 length   array           13752
0x00955abf length   array              32
0x009566cd length   array               4
0x00956764 length   array               4
0x009567ca length   array               4
0x0095890b length   array               4
0x00958913 length   array               4
0x009589ba length   array               4
0x009589c2 length   array               4
0x009589ca length   array               4
0x07b01e06 length   array               1
0x09804806 getprop  object          16742
0x09807e21 length   array               4
0x09807fd3 length   array            4304
0x09817390 length   array              48
0x09817950 length   array              32
0x098187f5 length   array               4
0x0c66384e length   array           79872
V8-V4, GETPROP, shape variation.

 #shapes   #sites   #execs
       1     1240 85143982
       2       73  1700639
       3       41  1185392
       4       15  4060595
       5       19  2184436
      10       20  8628540
      14        1   399566

 #shapes = number of shapes at a given getprop pc
 #sites  = number of static getprop pcs with #shapes different shapes
 #execs  = number of getprop ops executed at pcs with #shapes diff. shapes
I looked at GETELEM for v8-v4. I found that there are very few (~30,000) accesses that don't hit dense arrays, and those don't have many shapes in common (usually a different shape each time) so I think there we just need a fast path for dense arrays. As we already know, we aren't getting dense arrays for all the numeric code there, so being more aggressive about that would also help.
Conclusions:

- For |.length| accesses, the PIC only needs to generate one stub, either for strings or arrays, and then go to the slow path always after that.

- For |.foo| accesses, SunSpider requires only 4 stubs per site, but V8 can require up to 14 stubs per site. Whether that actually makes things faster requires another test.

- For |[foo]| accesses, it's not worth caching, except possibly if |foo| is a constant non-numeric string.
Status: NEW → RESOLVED
Closed: 15 years ago
Resolution: --- → FIXED
A question I haven't treated yet is what kind of variation we see in prototype chains. In particular, WebKit always generates only self stubs, direct proto stubs, or proto chain stubs for a given PIC, and I want to know if this is sufficient. Here are stats for SunSpider:

Histogram of chain lengths (dynamic):

  len    count
  1    2109348
  2      23009

This means there are 2.1M dynamic accesses with chain length 1 (i.e., self property) and 23K with chain length 2 (i.e., direct proto). Nothing more is needed for SS, apparently.

Histogram of chain length combinations (static):
  lens      count
  (1,)     567405
  (2,)      14010

This means there are .5M getprop sites where the chain length is always 1, and 14K where it is always 2. Thus, at each site we have only proto accesses or only self accesses, never both.

Histogram of chains (s/d):
       1      225  1680715
       2        7    13528
       3        1      795
       4       16   437319

This is like the histograms above except it is for every shape on the chain, not just the base object. Not surprisingly, given the preponderance of self accesses, it's about the same as the original result.
Proto chain counts for v8:

Histogram of chain lengths (dynamic):
1  102894899
2     426671

Histogram of chain length combinations (static):
(1,)       1397
(1, 2)          8
(2,)          2

Histogram of chains (s/d):
       0     1237 85143142
       1       65  1596759
       2       49  1291790
       3        7  3917685
       4       11   247246
       5       16  2080100
       6       20  8628540
       7        1    16742
       8        1   399566

Not sure why the shapes don't quite match up with the earlier results. Another thing to note is that this didn't find any chains longer than 2. We know some chains are in there because we had to improve handling of them to get stuff to trace. Maybe those are for callprops.

v8, at least, looks like it might benefit from being able to have both self and proto entries at a given site.
Check gmail. As noted in bug 411630 comment 2 it used to have very deep chains, and varying length for a given site. This was (and I believe is still) due to the closure compiler. Google open-sourced that last year.

/be
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