Refactor: consolidate per-task markers into one TaskAttrs byte (a5/tmr)

[ChaoZheng109]

Summary

Mirrors the a2a3/tmr consolidation (#1402) to the a5 tensormap_and_ringbuffer runtime. Folds the four scattered per-task markers into a single TaskAttrs byte on PTO2TaskSlotState and reverts active_mask to a pure subtask-slot mask. a5/tmr was structurally identical to the a2a3 baseline, so this is a 1:1 port with the same settled design.

Changes

• New TaskAttrs (pto_submit_types.h) — one byte: bit0 allow_early_resolve, bit1 sync_start, bit2 has_predicate, bit3 is_timed, bits4-7 timing_tag (0..15).
• ActiveMask reverts to pure subtask-slot mask — dropped SYNC_START/HAS_PREDICATE bits/accessors; only core_mask (bits 0-2) remains.
• task_timing_slot removed from PTO2TaskDescriptor — tag now rides the hot slot_state line. Descriptor 40B / packed_buffer_base offset unchanged (ABI preserved). PTO2TaskSlotState stays 64B.
• Attributes written once per submit in prepare_task; all scheduler read sites updated. static_assert couples the 4-bit tag to NUM_TASK_TIMING_SLOTS <= 16 / TASK_TIMING_SLOT_NONE == -1.
• Accessor naming matches the a2a3 baseline: predicate getters (allow_early_resolve/requires_sync_start/has_predicate/is_timed), set_<concept> setters.

Testing

• test_a5_wiring (cpput)
• a5sim st: predicated_dispatch, spmd_sync_start{,_early_dispatch,_stress,_mix_spill}, mixed_example, dummy_task, spmd_multiblock_mix
• a5 hardware — deferred (this box is Ascend910/a2a3)

Relation to #1402

a5/tmr mirror of the a2a3/tmr baseline. Remaining: a2a3 host_build_graph, a5 host_build_graph (legacy path). Part of #1402.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: f5447c67-05d3-4ef4-a982-4aeab1680e99

📥 Commits

Reviewing files that changed from the base of the PR and between a7a29ee and 2e9fc68.

📒 Files selected for processing (8)

• src/a5/runtime/tensormap_and_ringbuffer/docs/RUNTIME_LOGIC.md
• src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_orchestrator.cpp
• src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_runtime2_types.h
• src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_submit_types.h
• src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_types.h
• src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/pto_scheduler.h
• src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/scheduler_completion.cpp
• src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/scheduler_dispatch.cpp

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📝 Walkthrough

Walkthrough

Changes

Task attribute scheduling migration

Layer / File(s)	Summary
Define packed task attributes src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_submit_types.h, src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_types.h, src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_runtime2_types.h	TaskAttrs stores early-resolve, sync-start, predicate, and timing metadata, while ActiveMask retains only subtask-mask state and slot layouts enforce the updated ABI.
Thread attributes through task submission src/a5/runtime/tensormap_and_ringbuffer/runtime/pto_orchestrator.cpp	Submission, dummy tasks, allocation tasks, and fan-in wiring construct or consume TaskAttrs through prepared slot state.
Apply attributes to ready and early-dispatch routing src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/pto_scheduler.h, src/a5/runtime/tensormap_and_ringbuffer/docs/RUNTIME_LOGIC.md	Ready-queue placement, predicate filtering, early-resolution checks, fan-in propagation, and sync-start routing use task_attrs.
Use attributes during dispatch and completion src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/scheduler_dispatch.cpp, src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/scheduler_completion.cpp	Dispatch synchronization, timing publication and completion, pending gating, and promotion logic read timing and sync-start state from task_attrs.

Estimated code review effort: 4 (Complex) | ~45 minutes

Possibly related issues

• [Code Health] Consolidate scattered per-task markers into one "task markers" byte; keep active_mask a pure subtask-slot mask #1402 — Introduces the TaskAttrs consolidation for timing, sync-start, predicate, and early-resolve metadata.

Possibly related PRs

• hw-native-sys/simpler#1405 — Modifies the same early-dispatch fan-in and candidate-enqueue logic.
• hw-native-sys/simpler#1410 — Refactors the same per-task flags and timing-slot plumbing across orchestrator and scheduler code.
• hw-native-sys/simpler#1423 — Overlaps in early-resolve and sync-start handling across orchestration and scheduler paths.

Poem

A rabbit packed flags in a byte neat and bright,
Sync-start and timing now hop through the night.
Predicates leave masks, early resolve takes flight,
Slots carry attributes, dispatch feels right.
“One hop at a time!” says the rabbit in glee.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 20.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: consolidating per-task markers into a TaskAttrs byte in a5/tmr.
Description check	✅ Passed	The description is directly related and matches the task-attribute consolidation and scheduler updates in the diff.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[ChaoZheng109]

Folding the a5/tmr change into #1410 instead of a standalone PR, per request.