Introduce cache modifiers

[mawad-amd]

Motivation

This PR introduces support for cache modifiers and volatile flags in Iris' distributed memory operations (load, store, get, put).
The goal is to provide fine-grained control over caching behavior at different cache levels. This allows developers to have fine grained control over caching behavoir.

Technical Details

Changes include:

• Extended load with cache_modifier and volatile options.
• Extended store with cache_modifier.
• Extended get and put with both load_cache_modifier and store_cache_modifier.
• Docstrings updated to document supported values and behavior.
• Fixed error propagation in tests/run_tests_distributed.py to correctly forward worker exit codes.
• Added new unit tests covering all cache modifier combinations and volatile option.

Test Plan

I added comprehensive tests under tests/unittests:

• test_load_cache_modifiers.py – verifies iris.load with all cache modifiers and volatile settings.
• test_store_cache_modifiers.py – verifies iris.store with all store cache modifiers across ranks.
• test_get_cache_modifiers.py – verifies iris.get with load/store cache modifier combinations.
• test_put_cache_modifiers.py – verifies iris.put with load/store cache modifier combinations.

Each test checks correctness by comparing against expected tensors across distributed ranks.

Test Result

See CI

Submission Checklist

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

[Copilot]

Pull Request Overview

This PR adds cache modifier support to the Iris framework's load and store operations. The changes enable fine-grained control over GPU cache behavior during memory operations, allowing developers to optimize performance by specifying how data should be cached across the CU (L1), L2, and LLC levels.

Key changes:

• Enhanced load() and store() functions with cache_modifier and volatile parameters
• Added comprehensive test coverage for different cache behaviors (default, writeback, cache global, cache streaming, write-through, and volatile)
• Updated function documentation to explain cache modifier options and their effects on GPU cache hierarchy

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
iris/iris.py	Enhanced load() and store() functions with cache_modifier and volatile parameters, plus detailed documentation
tests/unittests/test_load_cache_modifiers.py	New comprehensive test suite covering all cache modifier behaviors and volatile flag

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.