compiled method info

[Xin Tong]

On Thu, May 3, 2012 at 6:07 PM, Krystal Mok <rednaxelafx at gmail.com> wrote:
> Hi Xin,
>
> +1 with John, Google is your friend when you start investigating things, especially when the top hits are pretty good.
>
> Comments inline,
>
> On 2012-5-4, at 4:20, Xin Tong <xerox.time.tech at gmail.com> wrote:
>
>> On Thu, May 3, 2012 at 4:13 PM, Christian Thalinger
>> <christian.thalinger at oracle.com> wrote:
>>>
>>> On May 3, 2012, at 11:54 AM, Xin Tong wrote:
>>>
>>>> I am new to hotspot JVM. I am wondering how can I get a log of all the
>>>> method compiled
>>>
>>> You can print the compiled methods with -XX:+PrintCompilation.
>>
>> This will print the compiled method to the stdout, is there a way to
>> force it to some output file ?
>
> You can learn more about all available VM options in the *globals.hpp files.
> Supposing you can read Chinese, there's a thread that I posted some time ago that had a list of all *globals.hpp files in it: http://hllvm.group.iteye.com/group/topic/27945
>
> In runtime/globals.hpp, you can find the flags LogVMOutput and LogFile that should meet your needs. Use them like this (if you're using a product build):
> -XX:+UnlockDiagnosticVMOptions -XX:+LogVMOutput -XX:LogFile=<file_path>
>
> The default path for the log is ./hotspot.log.
>

The debugging output gets printed to the file i specified. However the
same thing is printed to the stdout. How can i get it just print to
the file, not stdout. also, i have been looking at this document and
can not find the LogFile option in there.

http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html

Maybe this doc is out of date ? or the JVM version is old ?

>>>
>>>> and how can i get the intermediate representation
>>>
>>> This is more complicated.  Do you mean the graph that's produced during the compile?
>>>
>>>> and
>>>> optimizations performed on one particular method ?
>>
>> Yes. I used to work on some other compiler framework in which one is
>> able to print the graph after every optimization.
>
> Search for C1Visualizer and IdealGraphVisualizer and read their manual. Should be enough to get you started.
>
>>
>>>
>>> Depends on the compiler used.  You might get an idea what's going on using -XX:+TimeCompiler (this is only available in a non-product build).
>>>
>>
>> I used make all  to build openJDK. however, all the developer options
>> are not available. How do i make a non-product build. I do not want a
>> debug build, as debug build tend to run slower than prod build.
>>
>
> That's what a fastdebug build is for. It's faster than a (slow) "debug" build, even though slower than a product build. You could refer to a script that Charles Nutter wrote for building HotSpot:
> https://gist.github.com/1148321 . Use "build.sh fastdebug" to get a fastdebug build.
>
> - Kris
>
>>
>> -- Xin
>>
>>> -- Chris
>>>
>>>>
>>>> Thanks
>>>>
>>>> Xin
>>>
>