563564 - TM: Investigate benchmark regexp execution time

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Chris Leary [:cdleary] (not checking bugmail)]

V8 w/JIT:
       compiled:    46ms (268635 data points)
     uncompiled:   343ms (309420 data points)

V8 w/o JIT:
       compiled:     0ms (0 data points)
     uncompiled:   507ms (578055 data points)

Indicates a 3.6x speedup on JITted regexps.

SunSpider w/JIT:
       compiled:    17ms (5310 data points)
     uncompiled:    32ms (95648 data points)

SunSpider w/o JIT:
       compiled:     0ms (0 data points)
     uncompiled:   132ms (100920 data points)

Indicates a 5.9x speedup on JITted regexps.

List of top uncompiled culprits soon to follow...

Comment 1

[Chris Leary [:cdleary] (not checking bugmail)]

Attachment: Probe regexp execution.

Comment 2

[Chris Leary [:cdleary] (not checking bugmail)]

Scores on v8-regexp:

moz-central nightly: 183
webkit nightly: 1065
chrome for mac beta: 1431

Comment 3

[Chris Leary [:cdleary] (not checking bugmail)]

Attachment: Regexp top contenders.

Regular expression execution times sorted by milliseconds spent in them, descending.

Comment 4

[Chris Leary [:cdleary] (not checking bugmail)]

(In reply to comment #3)
> by milliseconds spent in them,

Er, make that microseconds. Upon further reflection, I do not have a 2.9MHz CPU.

Comment 5

[Chris Leary [:cdleary] (not checking bugmail)]

Marking as resolved.

Comment 6

[Andreas Gal :gal]

Whats your total sunspider time? I am trying to figure out what % of time we spend in regexp of a total SS score. That shows us the max speedup we can obtain from this.

Comment 7

[Chris Leary [:cdleary] (not checking bugmail)]

With JIT: ~443ms
Without JIT: ~1374ms

Numbers have probably changed a little since I took those measurements, but not by much. So about 7% time spent in uncompiled regexps. We could shave an estimated 26.5ms off of the total time with all compiled regexps at the same projected speedup (5.9x) -- that's idealized because the regexps we'd be compiling would be significantly more complex.