[ARM][AArch64] Remove CLS special handling and use generic ISD::CTLS node

[RKSimon]

Once #173417 has landed, the arm/aarch64 intrinsics (int_arm_mve_vcls/int_arm_neon_vcls/int_aarch64_cls/int_aarch64_cls64 etc.) can be expanded to ISD::CTLS in DAG/GISel and the remaining patterns/setOperationAction calls converted to use ISD::CTLS

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. Check that no other contributor is working on this issue. If someone is assigned to the issue or claimed to be working on it, ping the person. After one week without a response, the assignee may be changed.
2. Leave a comment indicating that you are working on the issue, or just create a pull request after following the steps below. Mention this issue in the description of the pull request.
3. Fix the issue locally.
4. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
5. Create a Git commit.
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7. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation. Mention this issue in the description of the pull request.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-backend-arm

Author: Simon Pilgrim (RKSimon)

Details

Once #173417 has landed, the arm/aarch64 intrinsics (int_arm_mve_vcls/int_arm_neon_vcls/int_aarch64_cls/int_aarch64_cls64 etc.) can be properly removed and the remaining patterns/setOperationAction calls converted to use ISD::CTLS

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

Author: Simon Pilgrim (RKSimon)

Details

Once #173417 has landed, the arm/aarch64 intrinsics (int_arm_mve_vcls/int_arm_neon_vcls/int_aarch64_cls/int_aarch64_cls64 etc.) can be properly removed and the remaining patterns/setOperationAction calls converted to use ISD::CTLS

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: Simon Pilgrim (RKSimon)

Details

Once #173417 has landed, the arm/aarch64 intrinsics (int_arm_mve_vcls/int_arm_neon_vcls/int_aarch64_cls/int_aarch64_cls64 etc.) can be properly removed and the remaining patterns/setOperationAction calls converted to use ISD::CTLS

[HamzaHassanain]

Can I work on this?

I can keep an eye on the PR, once landed, I can start working on the issue!

[topperc]

the arm/aarch64 intrinsics (int_arm_mve_vcls/int_arm_neon_vcls/int_aarch64_cls/int_aarch64_cls64 etc.)

@RKSimon are you suggesting the frontend should emit one of the patterns in place of the intrinsics?

[RKSimon]

I was thinking more in terms of DAG/GISel handling, I'm not suggesting a llvm.ctls intrinsic is necessary right now, and not expand the intrinsic into a ctlz series either.

[RKSimon]

First stage: #174367

[HamzaHassanain]

Hello @RKSimon !
Since the PR has landed, can I start working on this issue?