[llvm-dev] [GPUCC] how to remove _ZL21__nvvm_reflect_anchorv() automatically?

[Artem Belevich via llvm-dev]

David's change makes nvvm_reflect_anchor unnecessary. The issue with dots
in names generated by llvm still needs to be fixed.
On Apr 9, 2016 8:32 AM, "Jingyue Wu" <jingyue at google.com> wrote:

> Artem,
>
> With David's http://reviews.llvm.org/rL265060, do you think
> __nvvm_reflect_anchor is still necessary?
>
> On Fri, Apr 8, 2016 at 9:37 AM, Yuanfeng Peng via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Yeah, '.' is the direct reason for the ptxas failure here.  I'm curious,
>> however, about what the purpose of nvvm_reflect_anchorv() is here, and why
>> does the front-end always generate this function? Since the current PTX
>> emission doesn't mangle dots, it would be a reasonable workaround for me to
>> prevent the front-end from generating this function in the first place.
>> Is there any magic option available to do so?
>>
>> Thanks!
>> yuanfeng
>>
>> On Thu, Apr 7, 2016 at 5:19 PM, Reid Kleckner <rnk at google.com> wrote:
>>
>>> The actual problem here is that PTX appears to not allow '.' in symbol
>>> names. We should probably just change our PTX emission to mangle dots
>>> somehow.
>>>
>>> On Thu, Apr 7, 2016 at 4:24 PM, Yuanfeng Peng via llvm-dev <
>>> llvm-dev at lists.llvm.org> wrote:
>>>
>>>> Hi,
>>>>
>>>> I needed to compile a cuda source file (say, a.cu) into IR (a.bc), and
>>>> then merge a.bc with another bitcode file (b.bc, compiled from b.cu).
>>>> So I used *llvm-link a.bc b.bc -o c.bc*
>>>>
>>>> However, I noticed that an internal function '* _ZL21__nvvm_reflect_anchorv()
>>>> *' is defined in both a.bc & b.bc, and when merging these two files,
>>>> one of the two definitions was renamed to  '
>>>> *_ZL21__nvvm_reflect_anchorv.2()*', and written into c.bc.
>>>>
>>>>  Then I did *llc c.bc -o c.s -march=nvptx ; ptxas c.s -o c.o*
>>>>
>>>> However, ptxas would give the following complaint:
>>>>
>>>> *ptxas c.s, line 171; error   : Duplicate definition of function
>>>> '_ZL21__nvvm_reflect_anchorv'*
>>>>
>>>> *ptxas c.s, line 171; fatal   : Parsing error near '.2': syntax error*
>>>>
>>>> So I inspected c.s and found the issue above was caused by the
>>>> following line:
>>>>
>>>> .*func**  (.param .b32 func_retval0) _ZL21__nvvm_reflect_anchorv.2()
>>>> // @_ZL21__nvvm_reflect_anchorv.2*
>>>>
>>>> After I manually deleted the definition of this function in c.s, the
>>>> compilation works file.  I wonder how could I force llc to remove  *`*
>>>> _ZL21__nvvm_reflect_anchorv.2*()`*? Or is that possible to prevent
>>>> _ZL21__nvvm_reflect_anchorv*() *from being generated into a.bc & b.bc
>>>> in the first place?  Or is this possible to ask llvm-link to NOT
>>>> rename *_ZL21__nvvm_reflect_anchorv() **into *
>>>> *ZL21__nvvm_reflect_anchorv**.2**()*?
>>>>
>>>>
>>>> Thanks!
>>>>
>>>> *Yuanfeng Peng *
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> LLVM Developers mailing list
>>>> llvm-dev at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>>
>>>>
>>>
>>
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>
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