Bug 70460 – DFG JIT 32_64 - remove unnecessary double unboxings in fillDouble/fillSpeculateDouble

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Yuqiang Xian]

As pointed out by Gavin in bug #70418, when a value is already in memory we can avoid loading it to two GPRs at first and then unboxing them to a FPR.

[Yuqiang Xian]

Created attachment 111703 [details]
the patch

[Yuqiang Xian]

Performance result based on current code base w/ DFG 32bit turned on (on Linux ia32 Core i7 Nehalem) -

Kraken:

TEST                         COMPARISON            FROM                 TO             DETAILS

=============================================================================

** TOTAL **:                 1.087x as fast    7272.1ms +/- 0.3%   6688.4ms +/- 0.1%     significant

=============================================================================

  ai:                        1.002x as fast     797.2ms +/- 0.2%    795.3ms +/- 0.1%     significant
    astar:                   1.002x as fast     797.2ms +/- 0.2%    795.3ms +/- 0.1%     significant

  audio:                     1.116x as fast    2376.4ms +/- 0.8%   2130.0ms +/- 0.2%     significant
    beat-detection:          1.108x as fast     702.2ms +/- 2.7%    634.0ms +/- 0.5%     significant
    dft:                     1.27x as fast      557.7ms +/- 0.2%    439.4ms +/- 0.5%     significant
    fft:                     1.123x as fast     534.6ms +/- 0.4%    476.1ms +/- 0.1%     significant
    oscillator:              -                  581.9ms +/- 0.3%    580.5ms +/- 0.1%

  imaging:                   1.129x as fast    2920.6ms +/- 0.2%   2586.2ms +/- 0.1%     significant
    gaussian-blur:           1.35x as fast     1278.9ms +/- 0.1%    950.8ms +/- 0.1%     significant
    darkroom:                1.003x as fast     715.8ms +/- 0.2%    713.5ms +/- 0.1%     significant
    desaturate:              -                  925.9ms +/- 0.5%    921.9ms +/- 0.3%

  json:                      -                  194.6ms +/- 0.5%    193.9ms +/- 0.5%
    parse-financial:         1.006x as fast      82.1ms +/- 0.3%     81.6ms +/- 0.5%     significant
    stringify-tinderbox:     -                  112.5ms +/- 1.0%    112.3ms +/- 0.8%

  stanford:                  -                  983.3ms +/- 0.2%    983.0ms +/- 0.3%
    crypto-aes:              ??                 164.7ms +/- 0.5%    165.6ms +/- 0.6%     not conclusive: might be *1.005x as slow*
    crypto-ccm:              -                  141.3ms +/- 0.7%    140.5ms +/- 0.6%
    crypto-pbkdf2:           -                  572.7ms +/- 0.2%    572.4ms +/- 0.3%
    crypto-sha256-iterative: -                  104.6ms +/- 0.4%    104.5ms +/- 0.5%

[WebKit Review Bot]

Comment on attachment 111703 [details]
the patch

Clearing flags on attachment: 111703

Committed r97928: <http://trac.webkit.org/changeset/97928>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.