[webkit-qt] QtWebKit 2.3.1 on MIPS

[Allan Sandfeld Jensen]

On Wednesday 24 April 2013, Massimo Callegari wrote:
> - V8 engine: it seems it has been abandoned for WebKit1 and it is the
> default on Qt5/WebKit2. Is this correct or is there still a way to use V8
> on QtWebKit 2.3.1 (like the old option --v8) ?
> 
I have not experimented with V8 and QtWebKit, and I don't know how much work 
it will be to reintegrate that, but I think it has not been maintained for 
some time.

> - JSC MIPS: reading around, I've seen it should be possible to use MIPS
> assembler code into JavaScriptCore. Anyone knows how I can do it? Right
> now I'm passing -mips32 flag but it seems to be not enough. Shoud I add
> -march=mips or something similar to enable CPU(MIPS) into JSC ?
> 
JavaScriptCore in QtWebKit 2.3.1 and Qt 5 should be using MIPS JIT already, 
but only the first generation JIT. The second generation DFG JIT for MIPS is 
in WebKit trunk, and so is LLInt for MIPS. LLInt is the low level interpreter 
that is used when JIT doesn't look profitable. Neither has been cherry-picked 
for Qt 5.1 nor QtWebKit 2.3 yet, but I am expected it to be in Qt 5.2.

It shouldn't be too hard to cherry-pick MIPS LLInt which should be somewhat 
faster than without, but the DFG JIT code is much more invasive and would take 
more effort. If you want to give a try at MIPS LLInt you can start at 
https://bugs.webkit.org/show_bug.cgi?id=99706

`Allan