Official support for mgpu vectorization hints

[neoblizz]

Motivation

This pull request adds support for vectorization hints to various distributed memory operations in the iris.py module. By introducing an optional hint parameter, the code now allows callers to specify alignment and vectorization preferences for pointer translation and memory access, which can lead to more efficient memory operations on supported hardware.

The most important changes are:

Vectorization hint support:

• Added an optional hint parameter (of type tl.constexpr) to the __translate function and all distributed memory operation methods (e.g., load, store, copy, get, and all atomic operations) in iris.py. This parameter allows callers to specify alignment and vectorization preferences for pointer translation. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16]
• Updated the pointer translation logic in __translate, copy, and related functions to apply the vectorization hint using tl.multiple_of and tl.max_contiguous when the hint is provided. [1] [2] [3]

Documentation updates:

• Updated docstrings for all affected functions to describe the new hint parameter, including usage examples and explanations of how to specify the hint for 1-D and N-D cases. [1] [2] [3] [4] [5]

These changes provide more control over memory access patterns, which can help optimize performance for distributed and vectorized workloads.

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.

[Copilot]

Pull request overview

Adds official mgpu vectorization hint support across Iris distributed-memory helpers, enabling callers to provide alignment/contiguity assumptions to improve generated memory code where valid.

Changes:

• Added an optional hint: tl.constexpr parameter to pointer translation and all distributed memory ops (load/store/copy/get/put/atomics).
• Applied tl.multiple_of + tl.max_contiguous to translated pointers when hint is provided.
• Expanded docstrings to document the new hint parameter on the public APIs.

[mawad-amd]

Let's introduce one new argument per hint and add tests.

[neoblizz]

Let's introduce one new argument per hint and add tests.

See the comment above.

The current local tests I was doing was assembly generation and inspection.