[llvm-dev] llvm outlining question

[Michael Kuperstein via llvm-dev]

I'm not aware of anything else in LLVM that performs outlining.
Ayal (CCed) may be able to help you regarding CodeExtractor fixes.

Thanks,
  Michael

On 12 April 2016 at 14:21, Minghwa Wang <mwang2 at cse.scu.edu> wrote:

> Thank you Michael and Tom for the quick reply.
>
> According to your experience and comments, CodeExtractor is buggy only
> works for special cases but not general enough for most usages. Then do we
> have other outlining solution in llvm? Or I have to repeat what Michel done
> before?
>
> Best regards,
> Ming-Hwa
>
> On Tue, Apr 12, 2016 at 1:48 PM, Michael Kuperstein <
> michael.kuperstein at gmail.com> wrote:
>
>> CodeExtractor sort of does this.
>>
>> First, it's a utility, not a pass - you'd still need to wrap it up with
>> pass that actually causes it to outlines what you want it to outline.
>>
>> Second, it's a bit buggy. There are, as far as I know, two in-tree users
>> of this utility: bugpoint, and partial inlining. Both of them are fairly
>> specialized use-cases, and don't actually exercise the full generality of
>> outlining an arbitrary region. And since a lot of cases are in practice
>> untested - they don't quite work.
>> I've had some fixes for this internally, but never actually upstreamed
>> them, and no longer have access to that codebase. So, you'll probably run
>> into the same issues if you try to do anything untrivial with it.
>>
>> Michael
>>
>>
>>
>> On 12 April 2016 at 13:24, Tom Chen via llvm-dev <llvm-dev at lists.llvm.org
>> > wrote:
>>
>>> Does this do what you want
>>> http://llvm.org/docs/doxygen/html/classllvm_1_1CodeExtractor.html?
>>>
>>> 2016-04-12 14:58 GMT-05:00 Minghwa Wang via llvm-dev <
>>> llvm-dev at lists.llvm.org>:
>>>
>>>> Is there any support for outlining in llvm?
>>>>
>>>> As we know outlining is the opposite of inlining and while refactoring,
>>>> if we can outlining common code into functions, then function merge
>>>> (supported by llvm) can be more efficient in reducing code size.
>>>>
>>>> If llvm support outlining, how to use it? Any documentation for it?
>>>>
>>>> Thanks,
>>>> Ming-Hwa
>>>>
>>>>
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>>>>
>>>
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>>
>
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