407600 - Compile SpiderMonkey with -Os on mac

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Robert Sayre]

Right now it uses -O2 because that is the global setting. It should probably use MODULE_OPTIMIZE_FLAGS to indicate -Os. I have tried using -Os as the global setting for mac, but it was slightly slower overall on our pageload tests. Last time I tried this, I was getting mixed results at -Os, but now it is uniformly faster.

SunSpider results:

-Os
============================================
RESULTS (means and 95% confidence intervals)
--------------------------------------------
Total:                  6566.4ms +/- 1.4%
--------------------------------------------

  3d:                    896.5ms +/- 3.0%
    cube:                321.5ms +/- 2.5%
    morph:               307.7ms +/- 3.9%
    raytrace:            267.3ms +/- 3.5%

  access:               1177.8ms +/- 4.3%
    binary-trees:        104.9ms +/- 6.0%
    fannkuch:            510.4ms +/- 4.3%
    nbody:               327.9ms +/- 4.4%
    nsieve:              234.6ms +/- 6.2%

  bitops:                952.4ms +/- 1.1%
    3bit-bits-in-byte:    89.5ms +/- 0.9%
    bits-in-byte:        132.1ms +/- 1.8%
    bitwise-and:         491.3ms +/- 1.4%
    nsieve-bits:         239.5ms +/- 2.1%

  controlflow:            82.6ms +/- 1.1%
    recursive:            82.6ms +/- 1.1%

  crypto:                469.5ms +/- 4.0%
    aes:                 231.8ms +/- 5.3%
    md5:                 114.2ms +/- 1.2%
    sha1:                123.5ms +/- 5.0%

  date:                  557.6ms +/- 2.7%
    format-tofte:        369.5ms +/- 3.7%
    format-xparb:        188.1ms +/- 1.8%

  math:                  679.5ms +/- 3.4%
    cordic:              272.4ms +/- 2.7%
    partial-sums:        264.7ms +/- 1.9%
    spectral-norm:       142.4ms +/- 10.1%

  regexp:                574.1ms +/- 2.3%
    dna:                 574.1ms +/- 2.3%

  string:               1176.4ms +/- 2.9%
    base64:              231.6ms +/- 2.9%
    fasta:               286.9ms +/- 4.6%
    tagcloud:            230.5ms +/- 1.8%
    unpack-code:         306.9ms +/- 2.7%
    validate-input:      120.5ms +/- 6.4%

-O2
============================================
RESULTS (means and 95% confidence intervals)
--------------------------------------------
Total:                  7086.0ms +/- 4.1%
--------------------------------------------

  3d:                    972.3ms +/- 5.0%
    cube:                342.6ms +/- 4.2%
    morph:               338.5ms +/- 6.1%
    raytrace:            291.2ms +/- 7.8%

  access:               1250.0ms +/- 4.1%
    binary-trees:        119.4ms +/- 8.5%
    fannkuch:            510.6ms +/- 4.9%
    nbody:               376.5ms +/- 4.4%
    nsieve:              243.5ms +/- 6.0%

  bitops:               1013.2ms +/- 2.9%
    3bit-bits-in-byte:    94.0ms +/- 2.7%
    bits-in-byte:        139.1ms +/- 7.5%
    bitwise-and:         526.0ms +/- 3.0%
    nsieve-bits:         254.1ms +/- 3.4%

  controlflow:            83.2ms +/- 9.1%
    recursive:            83.2ms +/- 9.1%

  crypto:                493.9ms +/- 9.5%
    aes:                 250.8ms +/- 9.8%
    md5:                 115.7ms +/- 6.9%
    sha1:                127.4ms +/- 11.8%

  date:                  591.4ms +/- 8.2%
    format-tofte:        395.1ms +/- 8.5%
    format-xparb:        196.3ms +/- 8.8%

  math:                  740.4ms +/- 7.7%
    cordic:              295.0ms +/- 6.5%
    partial-sums:        295.2ms +/- 9.2%
    spectral-norm:       150.2ms +/- 8.2%

  regexp:                726.8ms +/- 5.4%
    dna:                 726.8ms +/- 5.4%

  string:               1214.8ms +/- 3.1%
    base64:              246.6ms +/- 3.8%
    fasta:               295.1ms +/- 2.7%
    tagcloud:            241.1ms +/- 5.1%
    unpack-code:         312.3ms +/- 3.5%
    validate-input:      119.7ms +/- 3.2%

Comment 1

[Robert Sayre]

Attachment: Always use the production settings when building Firefox. (changes Mac to -Os, like linux)

Comment 2

[Robert Sayre]

Comment on attachment 292465 [details] [diff] [review]
Always use the production settings when building Firefox. (changes Mac to -Os, like linux)

I have this building on the tryserver to check for bustage.

Comment 3

[Brendan Eich [:brendan]]

Comment on attachment 292465 [details] [diff] [review]
Always use the production settings when building Firefox. (changes Mac to -Os, like linux)

Would be best to get bsmedberg or luser or another build module owner or peer to r+ -- I can sr (I always build my optimized test js shells with -Os on Mac OS X; IIRC there's a bug about using -Os globally, not sure where that stands).

Optimistically pre-approving.

/be

Comment 4

[Robert Sayre]

(In reply to comment #3)
> (From update of attachment 292465 [details] [diff] [review])
> IIRC there's a bug about using -Os globally, not sure where that stands).

I tried it and it was ~2-5% slower on Tp/Ts/Tdhtml, but much smaller. I am going to try selectively building modules with -O2 on linux to see if there are a few more hotspots that would benefit from higher optimization (gfx and sqlite already do this).

Comment 5

[(not currently active) Ted Mielczarek]

Sadly this won't actually help our nightly builds, since we explicitly set optimize flags:
http://lxr.mozilla.org/mozilla/source/tools/tinderbox-configs/firefox/macosx/mozconfig#15

We should probably change that to --enable-optimize and --enable-debugger-info-modules, although we still might be screwed if we want to do that on Linux, since we need to explicitly specify -gstabs+ there for breakpad.

Comment 6

[(not currently active) Ted Mielczarek]

Comment on attachment 292465 [details] [diff] [review]
Always use the production settings when building Firefox. (changes Mac to -Os, like linux)

Regardless of that, this patch is correct for what you want.  Maybe file a followup on the tinderbox mozconfigs?

Comment 7

[Robert Sayre]

(In reply to comment #6)
> (From update of attachment 292465 [details] [diff] [review])
> Regardless of that, this patch is correct for what you want.  Maybe file a
> followup on the tinderbox mozconfigs?

Filed bug 407794.

Comment 8

[Robert Sayre]

This is the wrong way to solve this problem. Fixing bug 407794 will give us the correct defaults here. This build junk can be added later if necessary.

Comment 9

[Brian Crowder]

Actually, we should probably still address this for Makefile.ref

Comment 10

[Robert Sayre]

(In reply to comment #9)
> Actually, we should probably still address this for Makefile.ref
> 

Fair enough. Should be -Os on gcc and -O1 for msvc.

Comment 11

[Brian Crowder]

Attachment: config.mk

Modifies the spidermonkey-local config.mk (the one used by Makefile.ref, shouldn't be used by Makefile.in -- someone please correct me if I am mistaken).

Comment 12

[(not currently active) Ted Mielczarek]

Comment on attachment 292477 [details] [diff] [review]
config.mk

passing the buck

Comment 13

[Robert Sayre]

Comment on attachment 292465 [details] [diff] [review]
Always use the production settings when building Firefox. (changes Mac to -Os, like linux)

I actually did land this as part of 407794, because we were unable to make -Os the default on mac.

Comment 14

[Brian Crowder]

config.mk: 3.19