Tracking legacy resolve train feature performance

[Yakkhini]

Change-Id: I9bb3f593b1e247977b371103fdd5ebb66821fcaa

Summary by CodeRabbit

• Chores
  • Adjusted branch predictor configuration: enabled resolved-update behavior for specific predictor subcomponents in one example configuration.
  • Relaxed forcing of resolved-update flags in another example configuration so those flags are configurable rather than always forced on.

[github-actions]

🚀 Performance test triggered: gcc12-spec06-0.8c

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: d8b8dfb8-72d5-41d8-a9ad-7352e0bc1841

📥 Commits

Reviewing files that changed from the base of the PR and between ad8ab1c and ea101a2.

📒 Files selected for processing (1)

• configs/example/kmhv3.py

💤 Files with no reviewable changes (1)

• configs/example/kmhv3.py

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📝 Walkthrough

Walkthrough

Configuration changes to KMHv3 examples: configs/example/idealkmhv3.py now sets resolvedUpdate = True for three branch predictor subcomponents when DecoupledBPUWithBTB is used; configs/example/kmhv3.py removes forced resolvedUpdate = True assignments for those same subcomponents in the same branch.

Changes

Cohort / File(s)	Summary
Ideal KMHv3 config configs/example/idealkmhv3.py	When args.bp_type == DecoupledBPUWithBTB, set resolvedUpdate = True for cpu.branchPred.mbtb, cpu.branchPred.tage, and cpu.branchPred.ittage.
KMHv3 config configs/example/kmhv3.py	Removed forcing resolvedUpdate = True for cpu.branchPred.mbtb, cpu.branchPred.tage, and cpu.branchPred.ittage in the DecoupledBPUWithBTB configuration path.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• Resolve align #621 — modifies DecoupledBPUWithBTB predictor config for mbtb/tage resolvedUpdate flags.
• Train ITTAGE at resolve stage #630 — changes resolvedUpdate handling for MBTB/TAGE/ITTAGE updates.
• Add kmhv3 #609 — touches the same setKmhV3*Params configuration functions.

Suggested labels

align-kmhv3

Suggested reviewers

• jensen-yan
• happy-lx

Poem

🐰 In configs gentle as a breeze,
Three predictors learn with ease,
Resolved at last, they hop in tune,
Fields aligned beneath the moon,
A tiny commit — a grateful snooze.

🚥 Pre-merge checks | ✅ 1 | ❌ 2

❌ Failed checks (1 warning, 1 inconclusive)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Title check	❓ Inconclusive	The PR title 'Tracking legacy resolve train feature performance' is vague and does not clearly describe the actual changes, which involve enabling/disabling resolvedUpdate flags in branch predictor configurations.	Replace with a more specific title that clearly indicates the primary change, such as 'Enable resolvedUpdate in ideal configuration for resolve train evaluation' or 'Disable resolvedUpdate on kmhv3 branch predictor configuration'.

✅ Passed checks (1 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch ideal-resolve-evaluation

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[github-actions]

🚀 Coremark Smoke Test Results

Branch	IPC	Change
Base (xs-dev)	2.2713	-
This PR	2.2713	➡️ 0.0000 (0.00%)

✅ Difftest smoke test passed!

[XiangShanRobot]

[Generated by GEM5 Performance Robot]
commit: ad8ab1c
workflow: On-Demand SPEC Test (Tier 1.5)

Ideal BTB Performance

Overall Score

	PR	Master	Diff(%)
Score	20.38	21.69	-6.05 🔴

[Yakkhini]

Disable resolve train on kmhv3 evaluation: https://github.com/OpenXiangShan/GEM5/actions/runs/24229545486

[github-actions]

🚀 Coremark Smoke Test Results

Branch	IPC	Change
Base (xs-dev)	2.2713	-
This PR	2.2953	📈 +0.0240 (+1.06%)

✅ Difftest smoke test passed!