refactor(gpu): moving unsigned_scalar_div_rem and signed_scalar_div_rem to the backend

[enzodimaria]

closes: please link all relevant issues

PR content/description

Check-list:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• Relevant issues are marked as resolved/closed, related issues are linked in the description
• Check for breaking changes (including serialization changes) and add them to commit message following the conventional commit specification

[agnesLeroy]

Hello! Thank you for this PR! Here are my comments 🙂

[pdroalves]

Thanks a lot @enzodimaria .
I added some comments regarding format and consistency within the backend. I'm not capable of reviewing the logic, though.

[pdroalves]

You can move this type of initialization to the variable definition.

[enzodimaria]

Since this->bitop_mem is only useful if is_divisor_power_of_two is true, I think it's better to keep this default initialization to nullptr, in order not to allocate potentially unused objects. That was a recommendation from Agnès. What do you think?

    this->bitop_mem = nullptr;
     ...

    if (is_divisor_power_of_two) {

      this->bitop_mem = new int_bitop_buffer<Torus>(
          streams, gpu_indexes, gpu_count, SCALAR_BITAND, params,
          num_radix_blocks, allocate_gpu_memory, size_tracker);
    }

[pdroalves]

Yes we need initialization but I was thinking on initializing them on declaretion, as in:

...
   int_unsigned_scalar_div_mem<Torus> *unsigned_div_mem = nullptr;
  int_bitop_buffer<Torus> *bitop_mem  = nullptr;
  int_scalar_mul_buffer<Torus> *scalar_mul_mem  = nullptr;
  int_sub_and_propagate<Torus> *sub_and_propagate_mem  = nullptr;

This should be equivalent to what you are doing, since it's on a constructor, but more succinct.

[enzodimaria]

Oh, I see! I can do that. But can I do it in a next PR, the one where I remove the booleans?

[enzodimaria]

Indeed, other functions already merge following this logic. So for consistency with what is already merged, I think we should keep everything like this. Then in a future PR, I will re-harmonize everything

[agnesLeroy]

(the PR will come right after we merge this @pdroalves)

[enzodimaria]

Thanks a lot @enzodimaria . I added some comments regarding format and consistency within the backend. I'm not capable of reviewing the logic, though.

Thank you very much!

[github-actions]

⚠️ This PR contains unsigned commits. To get your PR merged, please sign those commits (git rebase --exec 'git commit -S --amend --no-edit -n' @{upstream}) and force push them to this branch (git push --force-with-lease).

If you're new to commit signing, there are different ways to set it up:

Sign commits with gpg

Follow the steps below to set up commit signing with gpg:

1. Generate a GPG key
2. Add the GPG key to your GitHub account
3. Configure git to use your GPG key for commit signing

Sign commits with ssh-agent

Follow the steps below to set up commit signing with ssh-agent:

1. Generate an SSH key and add it to ssh-agent
2. Add the SSH key to your GitHub account
3. Configure git to use your SSH key for commit signing

Sign commits with 1Password

You can also sign commits using 1Password, which lets you sign commits with biometrics without the signing key leaving the local 1Password process.

Learn how to use 1Password to sign your commits.