[Athena] Clean up and split CI actions (Issue #504)

[syifan]

Summary

• Reduced from 19 GitHub Actions workflows to 9
• Removed 10 redundant/broken/never-succeeding workflows
• Split monolithic accuracy-report.yml (120 min) into 3 focused workflows: microbench (~15 min), polybench (~30 min parallel), embench (~30 min)
• Consolidated 3 separate calibration workflows into 1 with suite selector
• Changed rarely-used workflows to dispatch-only triggers

Changes

Removed (14 files deleted)

Workflow	Reason
h5-accuracy-report.yml	Duplicate of accuracy-report, 0 successes
polybench-sim.yml	Superseded by polybench-segmented
polybench-segmented.yml	Subsumed into new accuracy-polybench
diana-statistical-validation.yml	References non-existent scripts, 0 successes
h4-multicore-accuracy.yml	H4 not started, premature
ci-health-monitor.yml	Meta-monitoring bloat
ci-metrics-dashboard.yml	Never runs successfully, bloated
performance-profiling.yml	Rarely needed
performance-regression-monitoring.yml	0 successes, overlaps with performance-regression
cpi-comparison.yml	Ran on every push unnecessarily
embench-calibration.yml	Merged into calibration.yml
polybench-calibration.yml	Merged into calibration.yml
memory-bench-calibration.yml	Merged into calibration.yml
accuracy-report.yml	Split into 3 smaller workflows

Added (4 files)

• accuracy-microbench.yml — Fast microbenchmark accuracy (~15 min)
• accuracy-polybench.yml — PolyBench in 3 parallel groups (~30 min)
• accuracy-embench.yml — EmBench accuracy (~30 min)
• calibration.yml — Unified calibration (dispatch-only, suite selector)

Modified (3 files)

• matmul-calibration.yml — Changed to dispatch-only
• spec-bench.yml — Removed daily cron (SPEC unavailable on hosted runners)
• performance-regression.yml — PR-only (removed push trigger)

Final Workflow Inventory (9 total)

Workflow	Trigger	Purpose
ci.yml	push, PR	Build, lint, test
accuracy-microbench.yml	push (paths), dispatch	Microbenchmark accuracy
accuracy-polybench.yml	push (paths), dispatch	PolyBench accuracy (parallel)
accuracy-embench.yml	push (paths), dispatch	EmBench accuracy
calibration.yml	dispatch	Hardware calibration (all suites)
benchmark.yml	dispatch	M2 hardware benchmarking
matmul-calibration.yml	dispatch	Fast timing matmul CPI
performance-regression.yml	PR	Benchstat regression detection
spec-bench.yml	dispatch	SPEC benchmark validation

Test plan

• Verify CI workflow runs on this PR (ci.yml)
• Manually trigger accuracy-microbench to verify it works
• Check that no critical functionality was lost

Generated with Claude Code

[github-actions]

Performance Regression Analysis

Performance Benchmark Comparison

Compares PR benchmarks against main branch baseline.
Benchmarks: pipeline tick throughput across ALU, memory, mixed workloads.

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*Automated benchmark comparison via `go test -bench` + benchstat*