[llvm-dev] Status of docs/BitCodeFormat.rst?

Mehdi Amini via llvm-dev llvm-dev at lists.llvm.org
Thu Oct 13 11:10:53 PDT 2016


It is more than that: the ID was *freed* and that’s why it has been reused for something else.
We only support bitcode from version 3.0 and above.
There is really no point keeping in the documentation construct from 2.9 and before that we can’t read anymore today.

Hope this makes sense.

— 
Mehdi

> On Oct 13, 2016, at 11:09 AM, Ismail Badawi (ibadawi) <ibadawi at cisco.com> wrote:
> 
> I think it just changed formats which prompted a change in ID -- the code now uses TYPE_BLOCK_ID_NEW (= 17). I haven’t looked deeply to see how different it is.
> 
> Ismail
> 
>> On Oct 13, 2016, at 2:02 PM, Mehdi Amini <mehdi.amini at apple.com> wrote:
>> 
>> 
>>> On Oct 13, 2016, at 10:24 AM, Ismail Badawi (ibadawi) via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>>> 
>>> Hi folks,
>>> 
>>> A while back I noticed some outdated information in docs/BitCodeFormat.rst about how parameter attributes were encoded — it describes an old encoding that was changed in 3.3 with the introduction of attribute groups. I opened a bug about this (https://llvm.org/bugs/show_bug.cgi?id=28941) and started trying to write a patch, but along the way ran into more and more issues (e.g. new things not documented, things that were removed or changed formats).
>>> 
>>> So I’m wondering whether there is an interest in keeping this document up to date. I see that there are some commits to this file in 2016 so it’s not totally abandoned, but at the same time there is information that has been outdated for 5+ years.
>>> 
>>> Assuming there is an interest, I’m also wondering whether (or how) to approach fixing this incrementally. For example, in trying to document the new paramattr format, I noticed that the type format is also outdated, and there is a conflict in block ids (i.e. the old TYPE_BLOCK format which is documented used blockid=10, but blockid=10 is now used for PARAMATTR_GROUP_BLOCK),
>> 
>> For this particular example, it should just be removed I think. If I read correctly the history the TYPE_BLOCK was a 2.9 thing.
>> 
>>>> Mehdi
>> 
>> 
>>> so that fixing the paramattr docs on their own might introduce inconsistencies. Would it be better to try & bring the whole document up to date at once, or would it be fine to do it incrementally & possibly introduce some strangeness in the intermediate steps?
>>> 
>>> Thanks,
>>> Ismail
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>> 
> 



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