Thanks for answer.
Let's say I don't know anything about try/catch/with and I'm using latest 
node/V8.
Which flag I need to set to know the reason that function isn't optimizable?
On older V8 versions I have the bailout info.


On Sunday, July 29, 2012 12:59:04 PM UTC+2, Jakob Kummerow wrote:
>
> --trace-bailout informs you when the optimizing compiler tried to optimize 
> a function but had to cancel this attempt half-way through. That's 
> unfortunate because it means that all the work it did before the 
> cancellation was a waste of time.
>
> Since V8 3.9.20, we have infrastructure in place that allows us to disable 
> optimization for functions that contain unsupported statements (such as 
> try-catch, with) right away, so the optimizing compiler never even tries to 
> optimize these and therefore doesn't have to bail out.
>
> There are other situations when the optimizing compiler has to bail out 
> that we don't detect up front, so the flag is still useful and it still 
> prints information in such cases.
>
> Long story short: it's a feature, not a bug :-)
>
>
> On Sun, Jul 29, 2012 at 2:09 AM, Sławek Janecki <[email protected]> wrote:
>
>> Using Node.js up to version  0.7.6 (v8 3.9.17) when I use --trace-bailout 
>> flag i have output as expected (bailouts info)
>>
>> Using Node from version 0.7.7 (v8 3.9.24.7) up to latest release 0.8.4 
>> --trace-bailout don't show any info.
>>
>> I've tried simple scripts with try/catch and 'with' (100% bailouts)
>>
>> Tracing hydrogen output on both node/v8 (0.7.6 and 0.7.7) versions tells 
>> that my test function (with try/catch and 'with') is'nt optimized (it's 
>> bailing-out) but I don't see any info on node >= 0.7.7
>>
>> Something changed? In V8 sources bailout flag is in place. 
>> Do I need to turn other flag on to get bailouts or this is a bug?
>>
>> Thanks
>>
>>
> 

-- 
v8-users mailing list
[email protected]
http://groups.google.com/group/v8-users

Reply via email to