Bug 153226 – [mips] Unaligned halfword load is not handled properly in macro assembler

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Julien Brianceau]

In mips macro assembler, the load16Unaligned(BaseIndex address, RegisterID dest) implementation is not efficient.

[Julien Brianceau]

Created attachment 269259 [details]
Provide a load16Unaligned implementation in mips macro assembler

Note: already contributed in qtwekbit http://code.qt.io/cgit/qt/qtwebkit.git/commit/?id=ea22657d17a934b04c8621dc8891a1d4d80510e3

[Julien Brianceau]

SunSpider's regexp-dna results on my mips board:

- without patch

    ============================================
    RESULTS (means and 95% confidence intervals)
    --------------------------------------------
    Total:     353.9ms +/- 0.5%
    --------------------------------------------

      regexp:  353.9ms +/- 0.5%
        dna:   353.9ms +/- 0.5%

- with patch

    ============================================
    RESULTS (means and 95% confidence intervals)
    --------------------------------------------
    Total:     136.5ms +/- 2.6%
    --------------------------------------------

      regexp:  136.5ms +/- 2.6%
        dna:   136.5ms +/- 2.6%

[Julien Brianceau]

Guillaume, do you have any feedback on this one ?

[Guillaume Emont]

(In reply to comment #3)
> Guillaume, do you have any feedback on this one ?

I couldn't say whether this is the fastest solution, though it might well be. It looks correct to me, and it runs well on my device.

[Michael Catanzaro]

Comment on attachment 269259 [details]
Provide a load16Unaligned implementation in mips macro assembler

rs=me. I don't understand all the code, but any error here would clearly be isolated to the MIPS platform, Guillaume has given his unofficial r+, it's been used in QtWebKit for almost two years, and no reviewer is working on MIPS.

[Konstantin Tokarev]

Comment on attachment 269259 [details]
Provide a load16Unaligned implementation in mips macro assembler

Works fine here and improves benchmark results. cq+

[WebKit Commit Bot]

Comment on attachment 269259 [details]
Provide a load16Unaligned implementation in mips macro assembler

Clearing flags on attachment: 269259

Committed r203226: <http://trac.webkit.org/changeset/203226>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.