Bug 19116 – SquirrelFish shouldn't regress on variable lookups

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Anthony Ricaud]

Nightlies have great performance improvements compared to Safari 3.1. SquirellFish shouldn't regress on that point. It's a test to compare lookups performance with variables in different scopes

For the record, here are the results I have on my machine :
FF3ß5
global : average : 44ms
local1 : average : 57.6ms
local2 : average : 55.8ms
local3 : average : 36.4ms

Opera 9.27
global : average : 79ms
local1 : average : 78.4ms
local2 : average : 79.2ms
local3 : average : 74.8ms

Opera 9.5
global : average : 51.4ms
local1 : average : 26.8ms
local2 : average : 35.6ms
local3 : average : 24ms

Safari 3.1
global : average : 90.8ms
local1 : average : 54.8ms
local2 : average : 44.8ms
local3 : average : 34.4ms

Webkit r33561
global : average : 17.8ms
local1 : average : 17.4ms
local2 : average : 16.4ms
local3 : average : 16ms

[Anthony Ricaud]

The original blog post of the author for more information : http://flesler.blogspot.com/2008/04/benchmarking-javascript-variables-and.html

[Mark Rowe (bdash)]

Are there measurements that suggest SquirrelFish is a regression over trunk on this microbenchmark?

[Oliver Hunt]

Mark, this is basically the tracking bug for the multiscope optimisation, squirrelfish performance is currently effectively a faster version of S3.1 -- basically resolve time for an out of scope var is O(N) wrt to closure depth, vs. effectively O(1) on trunk

[Oliver Hunt]

(I'm actually working on this atm)

[Oliver Hunt]

resolve is corrected
Committing to http://svn.webkit.org/repository/webkit/branches/squirrelfish ...
	M	JavaScriptCore/ChangeLog
	M	JavaScriptCore/VM/CodeBlock.cpp
	M	JavaScriptCore/VM/CodeBlock.h
	M	JavaScriptCore/VM/CodeGenerator.cpp
	M	JavaScriptCore/VM/CodeGenerator.h
	M	JavaScriptCore/VM/Machine.cpp
	M	JavaScriptCore/VM/Opcode.h
	M	JavaScriptCore/kjs/JSVariableObject.h
Committed r33958

Looks to be twice as fast as in trunk, still have base resolution to go

[Anthony Ricaud]

Squirellfish branch r33967:

global : average : 9.6ms
local1 : average : 8.8ms
local2 : average : 8.4ms
local3 : average : 8ms

I think it's not regressing :)

[Oliver Hunt]

Last fix (for read/write/modify operations) 
Committing to http://svn.webkit.org/repository/webkit/trunk ...
	M	JavaScriptCore/ChangeLog
	M	JavaScriptCore/kjs/nodes.cpp
Committed r34030

[Oliver Hunt]

*** Bug 18645 has been marked as a duplicate of this bug. ***

[Oliver Hunt]

*** Bug 18823 has been marked as a duplicate of this bug. ***