[alexander-sannikov]

Adds MPI device-side test coverage for NCCL Memory/LSA reduce-copy APIs and GIN PROXY signal paths

• DeviceApiMPITests.cpp (28 tests, wired into rccl-UnitTestsMPI):
  • baseline local/LSA copy and reduce/reduce-copy;
  • pointer APIs and LSA barriers (Group A);
  • fixed overloads, dtype sweep, coop-thread, in-place (Group B);
  • lambda layouts (Group C);
  • custom Min/Max reducers via test-local functors (Group D);
• GinDeviceMPITests.cpp (+8 signal tests):
  • VASignalAdd_Put
  • no-payload inc/add
  • signal read/reset
  • indexed signal SignalAdd/putValue
  • rolling-bit waits
  • strict-ordering VA signals
  • local shadow pointer helpers.
• vector__funcs.h: HIP fallback for int8_t 4-pack OpSum reduce (avoids missing __vadd4 on gfx950).

Issue Tracking

JIRA ID: AICOMRCCL-802

Test Plan

• CI validation enabled.
• manual validation.

Test Result

Manual validation:

Configuration	Topology	GTest result	Verdict
Device API full suite	2 ranks, 1 node	27 pass / 1 skip / 0 fail	Pass
GIN Phase-1 signals	2 ranks, 2 nodes	11 pass / 0 fail	Pass
VASignalAdd_Put (extra)	2 ranks, 2 nodes	1 pass	Pass

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/rocm-systems/blob/develop/CONTRIBUTING.md.

[therock-pr-bot]

✅ All Policy Checks Passed

Check	Status	Details
📝 PR Title/Description	✅ Pass	—
⛔ Forbidden Files	✅ Pass	—
🧪 Unit Test	✅ Pass	—
🚫 Draft PR	🔜 To Be Enabled	—
🚩 Feature Flag	🔜 To Be Enabled	—
📊 Code Coverage	🔜 To Be Enabled	—

🎉 All policy checks passed!

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[therock-pr-bot]

🚫 Please fix the failed policies before requesting reviews.

The following policy checks failed:

• ❌ Unit Test

The Not ready to Review label has been added to this PR.
Once all policies pass, the label will be removed automatically.

[github-actions]

RCCL Perf-Regression Gate: ✅ PASS

Mode: detect (reference vs candidate)
Thresholds (per-tier, calibrated): small 17.2% · mid 12.3% · large 12.9%
Keys compared: 0 · Confirmed regressions: 0 · Inconclusive: 0

Per-collective breakdown

group	keys	regressions	inconclusive
all_gather_perf-d=bfloat16-default	0	0	0
all_gather_perf-d=float-default	0	0	0
all_reduce_perf-d=bfloat16-default	0	0	0
all_reduce_perf-d=float-default	0	0	0
broadcast_perf-d=bfloat16-default	0	0	0
broadcast_perf-d=float-default	0	0	0
reduce_scatter_perf-d=bfloat16-default	0	0	0
reduce_scatter_perf-d=float-default	0	0	0

[alexander-sannikov]

%RCCL_TEST_CONFIG
mi300x_mellanox_ib.json
SUITE=Device API