[webkit-dev] jit for arm
Gavin Barraclough
barraclough at apple.com
Wed Nov 18 00:40:29 PST 2009
From http://lists.webkit.org/:
List Description
webkit-help [no description available]
Hmmm, yes, there would seem to be some scope to make that a little
more descriptive! ;-)
G.
On Nov 17, 2009, at 11:46 PM, Zoltan Herczeg wrote:
> Hi,
>
> seems the original mail was sent to both webkit-dev and webkit-help.
> My
> reply was on webkit-help, and the discussion continued there.
>
> https://lists.webkit.org/pipermail/webkit-help/2009-November/000380.html
>
> Perhaps we should clarify better the purpose of these mailing lists,
> since
> if people can't decide which list is better for them, they do double
> posts.
>
> Zoltan
>
>> On Nov 4, 2009, at 8:37 AM, ll Jefferry wrote:
>>
>>> Hi,
>>>
>>> when i reading the jit for arm source code, i am not very clear the
>>> functionality of the flowing functions:
>>> ctiTrampoline
>>
>> This code is used when entering from the C runtime into JIT generated
>> code. JIT generated code does not necessarily respect C calling
>> conventions, so this routine sets up the stack frame, preserves
>> registers, etc, as necessary to allow the JIT code to be run.
>>
>>> ctiVMThrowTrampoline
>>
>> To perform certain operations the JIT will call back into C code.
>> Usually the C callback can just return in a perfectly normal fashion
>> and continue execution once it has completed, however in the case
>> that
>> an exception is thrown special handling is required to change the
>> control flow. The return address of the C callback is instead
>> changed
>> to point to this, and this piece of code handles looking up the
>> exception handler at which execution will be resumed.
>>
>>> ctiOpThrowNotCaught
>>
>> This is used to from within cti_op_throw, which implements the
>> 'throw'
>> keyword in JavaScript. The cti_op_throw method will attempt to look
>> up a handler routine that catches the exception. However if the
>> exception is not caught it is necessary to force an early termination
>> of JIT execution. The cti_op_throw C callback always modifies its
>> return address, either to point to the code for the appropriate
>> exception handler to catch the exception, or to ctiOpThrowNotCaught
>> if
>> no handler is found.
>>
>>>
>>> could you explain to me?
>>> and another question is that: in cacheFlush function, why the
>>> system call number is 0xf0002? if it is defined by the toolchain?
>>
>> Zoltan, Gabor?
>>
>>>
>>>
>>> thanks!
>>>
>>> BR,
>>> Jeff
>>>
>>> _______________________________________________
>>> webkit-dev mailing list
>>> webkit-dev at lists.webkit.org
>>> http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
>>
>> _______________________________________________
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>> webkit-dev at lists.webkit.org
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>>
>
>
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