[llvm-dev] Custom Alloca implementation

[Alberto Barbaro via llvm-dev]

Hi Udit,
No problem at all. When you say at runtime you mean using the Interpreter
class or something else?

If I understood properly your problem I think you could do some
getDataLayout.getTypeAllocSize(I->getOperand(0)->getType());

Where is I is the reference to the Alloca instruction.

I hope it is correct :)

Alberto

On Mon, Jan 27, 2020, 13:40 Udit agarwal <dev.madaari at gmail.com> wrote:

> ---Adding llvm-dev list to CC---
> Hi Alberto,
>
> Thanks for your prompt reply. Actually, I need this information(about
> total allocation size and object structure) on runtime, so that is why I
> was planning to encode this info and store it in the memory itself.
>
> Regards,
> Udit
>
> On Mon, Jan 27, 2020 at 7:05 PM Alberto Barbaro <barbaro.alberto at gmail.com>
> wrote:
>
>> Hello Udit,
>> I'm not sure but can't you achieve the same just using metadata avoiding
>> to change the alloca instruction?
>>
>> Thanks
>> Alberto
>>
>> On Mon, Jan 27, 2020, 12:09 Udit agarwal via llvm-dev <
>> llvm-dev at lists.llvm.org> wrote:
>>
>>> Hello all,
>>>
>>> In my project, I need to allocate an extra 4 Bytes in every Alloca
>>> instruction. These additional bytes will be used to store the 'allocation
>>> info'(like size and structure of the allocated object etc). Instead of
>>> adding 4 bytes to the Alloca 'size' operand at every Alloca Instruction, I
>>> was thinking to make this change at the level where Alloca gets converted
>>> to machine IR.
>>> Can anyone please point me towards the code which actually handles this
>>> conversion(lowering of Alloca Inst)?
>>> --
>>> Regards,
>>> Udit kumar agarwal
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>
>
> --
> Regards,
> Udit kumar agarwal
> http://uditagarwal.in/
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200127/c88208e9/attachment-0001.html>