llvm dev - Apr 2012 - [LLVMdev] Question about PTXFrameLowering

Hi all,

I'm learning the PTX backend and confused by the following problem. In the
constructor of PTXFrameLowering, StackAlignment and LocalAreaOffset are
assigned 2 and -2, respectively. Since PTX has neither stack frame nor
stack pointer, why StackAlignment and LocalAreaOffset are needed and where
does 2 and -2 come from? Any explanation is appreciated. Thank you in
advance!

Yours Sincerely,
Lei Mou
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On Mon, Apr 16, 2012 at 3:48 AM, Lei Mou <lei.mou.uu at gmail.com> wrote:
> Hi all,
>
> I'm learning the PTX backend and confused by the following problem. In
the
> constructor of PTXFrameLowering, StackAlignment and LocalAreaOffset are
> assigned 2 and -2, respectively. Since PTX has neither stack frame nor
> stack pointer, why StackAlignment and LocalAreaOffset are needed and where
> does 2 and -2 come from? Any explanation is appreciated. Thank you in
> advance!
>
There's really no good reason for that.  Stack frames may be set up to
store .local variables, but that functionality is not 100% right now and
needs work.  The best I could say is, "don't worry about it." :)

>
> Yours Sincerely,
> Lei Mou
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>

-- 

Thanks,

Justin Holewinski
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Hi Justin,

Thank you for your reply. Then I'll just ignore this issue. :-)

Regards,
Lei Mou

On Mon, Apr 16, 2012 at 10:39 PM, Justin Holewinski <
justin.holewinski at gmail.com> wrote:
> On Mon, Apr 16, 2012 at 3:48 AM, Lei Mou <lei.mou.uu at gmail.com>
wrote:
>
>> Hi all,
>>
>> I'm learning the PTX backend and confused by the following problem.
In
>> the constructor of PTXFrameLowering, StackAlignment and LocalAreaOffset
are
>> assigned 2 and -2, respectively. Since PTX has neither stack frame nor
>> stack pointer, why StackAlignment and LocalAreaOffset are needed and
where
>> does 2 and -2 come from? Any explanation is appreciated. Thank you in
>> advance!
>>
>
> There's really no good reason for that.  Stack frames may be set up to
> store .local variables, but that functionality is not 100% right now and
> needs work.  The best I could say is, "don't worry about it."
:)
>
>
>>
>> Yours Sincerely,
>> Lei Mou
>>
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
>
>
> --
>
> Thanks,
>
> Justin Holewinski
>
>
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