1687143 - [meta] Reduce XDR size

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P1)

Description

[Tooru Fujisawa [:arai]]

After stencil-mvp, the size of XDR encoded data increases ~20%, and that affects IPC performance in JSBC, and that seems to affect raptor tp6 yahoo-mail performance.

Comment 1

[Tooru Fujisawa [:arai]]

Attachment: testing patch to gather XDR file size stat

Here's a testing patch that collects XDR data size, for each kind of data,
and prints them on decode
(I use decode because JSScript XDR replaces encoded data for delazifications)

the target of the stat can be specified by js::IsFileTargetOfStat in Xdr.cpp
currently set to gather raptor tp6 yahoo-mail JS files.

Comment 2

[Tooru Fujisawa [:arai]]

comparison of raptor yahoo-mail, mail_app_es6_09* JS file's XDR:

	before	after	diff	ratio
Version	22	22	0	0 %
AtomTable	594,193	1,977,500	+1,383,307	+232.8 %
ImmutableScriptData	1,982,888	1,984,138	+1,250	0 %
Scope	130,943	164,428	+33,485	+25.5 %
ScopeName	140,588	212,848	+72,260	+51.3 %
BigInt	0	18,808	+18,808	- %
Object	328,312	180,382	-147,930	-45.1 %
RegExp	320	19,320	+19,000	+5,937.5 %
GCThingData	646,028	479,194	-166,834	-25.9 %
ScriptData	343,395	765,064	+421,669	+122.7 %
ScriptExtra	428,848	490,212	+61,364	+14.3 %
SharedData	0	4,702	+4,702	- %
Module	0	0	0	- %
Source	3,071,613	3,071,613	0	0 %
Chunk	0	37,621	+37,621	- %
Total	7,667,150	9,405,852	+1,738,702	+22.6 %

also the data taken by initial vs delazifications in stencil XDR:

	initial	delazification
Version	22	0
AtomTable	19,065	1,958,435
ImmutableScriptData	14,369	1,969,769
Scope	27	164,401
ScopeName	16	212,832
BigInt	4	18,804
Object	4	180,378
RegExp	4	19,316
GCThingData	117,318	361,876
ScriptData	367,660	397,404
ScriptExtra	490,212	0
SharedData	1	4,701
Module	0	0
Source	3,071,613	0
Chunk	13	37,608
Total	4,080,328	5,325,524

Comment 3

[Tooru Fujisawa [:arai]]

Attachment: testing patch to gather XDR file size stat

• bug 1687093: span size data taken Scope/ScopeName/BigInt/Object/RegExp/GCThingData/ScriptData is reduced
• bug 1688327: memberInitializer is moved from ScriptData (initial and delazification) to ScriptExtra (only initial)

	2020-01-18	2020-01-26	Diff	Diff (%)
Version	22	22	0	0
AtomTable	1,977,500	1,977,500	0	0
ImmutableScriptData	1,984,138	1,984,138	0	0
Scope	164,428	150,321	-14,107	-8.6 %
ScopeName	212,848	194,040	-18,808	-8.9 %
BigInt	18,808	1,729	-17,079	-90.9 %
Object	180,382	163,303	-17,079	-9.5 %
RegExp	19,320	2,241	-17,079	-88.5 %
GCThingData	479,194	465,139	-14,055	-3 %
ScriptData	765,064	626,633	-138,431	-18.1 %
ScriptExtra	490,212	551,488	+61,276	+12.4 %
SharedData	4,702	4,702	0	0
Module	0	0	0	-
Source	3,071,613	3,071,613	0	0
Chunk	37,621	23,515	-14,106	-37.5 %
Total	9,405,852	9,216,384	-189,468	-2.1 %

Comment 4

[Tooru Fujisawa [:arai]]

Attachment: testing patch to gather XDR file size stat

• bug 1687428: Removed 4 bytes field (index) from ParserAtomEntry
• bug 1688886: Directly encode ImmutableScriptData that removes redundancy

(edited: there was error in GCThingData and ScriptExtra numbers)

	2020-01-26	2020-01-30	Diff	Diff (%)
Version	22	22	0	0%
AtomTable	1,977,500	1,777,768	-199,732	-10.2%
ImmutableScriptData	1,984,138	1,967,736	-16,402	-0.9%
Scope	150,321	150,321	0	0
ScopeName	194,040	194,040	0	0
BigInt	1,729	1,729	0	0
Object	163,303	163,303	0	0
RegExp	2,241	2,241	0	0
GCThingData	465,139	468,701	+3,562	+0.7%
ScriptData	626,633	626,633	0	0
ScriptExtra	551,488	551,488	0	0
SharedData	4,702	4,702	0	0
Module	0	0	0	-
Source	3,071,613	3,071,613	0	0
Chunk	23,515	23,515	0	0
Total	9,216,384	9,003,812	-212,572	-2.4%

Comment 5

[Tooru Fujisawa [:arai]]

Attachment: testing patch to gather XDR file size stat

• bug 1688534 : added the number of properties into XDR (increased the "Object" size)

(other difference seems to be caused by different number of delazifications, given different SharedData size)

	2020-01-30	2020-02-12	Diff	Diff (%)
Version	22	22	0	0.0%
AtomTable	1,777,768	1,778,008	+240	+0.0%
ImmutableScriptData	1,967,736	1,969,360	+1,624	+0.1%
Scope	150,321	150,951	+630	+0.4%
ScopeName	194,040	194,752	+712	+0.4%
BigInt	1,729	1,729	0	0.0%
Object	163,303	196,123	+32,820	+20.1%
RegExp	2,241	2,241	0	0.0%
GCThingData	468,701	469,877	+1,176	+0.3%
ScriptData	626,633	630,243	+3,610	+0.6%
ScriptExtra	551,488	554,188	+2,700	+0.5%
SharedData	4,702	4,732	+30	+0.6%
Module	0	0	0	-
Source	3,071,613	3,071,613	0	0.0%
Chunk	23,515	23,665	+150	+0.6%
Total	9,003,812	9,047,504	+43,692	+0.5%

Comment 6

[Tooru Fujisawa [:arai]]

also, here's self-hosted JS XDR size, on JS shell

category	bytes
Version	17
AtomTable	42702
ImmutableScriptData	158636
Scope	13925
ScopeName	20024
BigInt	4
Object	2323
RegExp	4
GCThingData	18280
ScriptData	9524
ScriptExtra	17140
SharedData	481
Module	0
Source	19
Chunk	9

Comment 7

[Tooru Fujisawa [:arai]]

• bug 1687095 : merge delazifications into initial stencil before encoding. now there's only one chunk with all data. (removed AtomTable duplication, and ScriptData duplication)

	2020-02-12	2020-03-03	Diff	Diff (%)
Version	22	22	0	0.0%
AtomTable	1,778,008	867,509	-910,499	-51.2%
ImmutableScriptData	1,969,360	1,969,360	0	0.0%
Scope	150,951	141,226	-9,725	-6.4%
ScopeName	194,752	194,752	0	0.0%
BigInt	1,729	4	-1,725	-99.8%
Object	196,123	192,557	-3,566	-1.8%
RegExp	2,241	516	-1,725	-77.0%
GCThingData	469,877	453,390	-16,487	-3.5%
ScriptData	630,243	307,884	-322,359	-51.1%
ScriptExtra	554,188	554,188	0	0.0%
SharedData	4,732	18,933	+14,201	+300.1%
Module	0	0	0	-
Source	3,071,613	3,071,613	0	0.0%
Chunk	23,665	6	-23,659	-100.0%
Total	9,047,504	7,771,960	-1,275,544	-14.1%

Now it's almost same as 7,667,150 bytes, that's before stencil XDR,
and this bug can be closed :)

Comment 8

[Tooru Fujisawa [:arai]]

(edited. the previous data was with --enable-debug)

self-hosted JS XDR data

category	bytes	borrowed bytes
Version	17	0
AtomTable	42,998	35,683
ImmutableScriptData	159,416	0
Scope	14,005	14,000
ScopeName	20,108	20,108
BigInt	4	0
Object	2,323	1,464
RegExp	4	0
GCThingData	18,398	18,392
ScriptData	9,564	9,560
ScriptExtra	17,212	17,208
SharedData	483	0
Module	0	0
Source	19	0
Chunk	45	0
TOTAL	284,596	116,415 (40.9%)

Comment 9

[Tooru Fujisawa [:arai]]

Attachment: testing patch to gather XDR file size stat

Comment 10

[Tooru Fujisawa [:arai]]

self-hosted JS XDR data, after bytecode pinning

category	bytes	borrowed bytes
Version	17	0
AtomTable	43,114	35,781
ImmutableScriptData	160,742	157,396
Scope	14,005	14,000
ScopeName	20,104	20,104
BigInt	4	0
Object	2,319	1,464
RegExp	4	0
GCThingData	18,324	18,320
ScriptData	9,564	9,560
ScriptExtra	17,212	17,208
SharedData	483	0
Module	0	0
Source	19	0
Chunk	49	0
TOTAL	285,960	273,833 (95.8%)

Comment 11

[Tooru Fujisawa [:arai]]

Attachment: testing patch to gather XDR file size stat