Tage tunning and L3 Cache size change

[edwu186]

apply tage tunning and enlarge L3 Cache size

Summary by CodeRabbit

• Chores
  • Updated branch predictor configuration parameters for enhanced prediction accuracy
  • Established default L3 cache memory size (32MB) during system initialization

[coderabbitai]

📝 Walkthrough

Walkthrough

Configuration initialization updates in the ideal KMH v3 example: conditional TAGE branch predictor parameter setup for DecoupledBPUWithBTB and default L3 cache size parameter establishment during main initialization.

Changes

Cohort / File(s)	Summary
Branch Predictor & Cache Configuration configs/example/idealkmhv3.py	Added conditional TAGE branch predictor table size and way configuration when using DecoupledBPUWithBTB; introduced default L3 cache size parameter (32MB) during __m5_main__ initialization before memory system construction.

Estimated Code Review Effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 Hops of joy with whiskers twitching bright,
Configuration tweaks, set just right,
TAGE tables dance, L3 caches hum,
Ideal parameters—oh what fun!
Performance awaits, the bits all aligned!

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

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.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title accurately reflects the two main changes: TAGE branch predictor tuning and L3 cache size adjustment to 32MB.

_{✏️ 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 tage-L3size-change

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[coderabbitai]

🧹 Nitpick comments (1)

configs/example/idealkmhv3.py (1)

145-145: Prefer default semantics over unconditional override for l3_size.

If 32MB is intended as the new default, this currently forces it even when users pass an explicit --l3-size/--l3_size. Consider preserving CLI intent.

♻️ Suggested adjustment

-    args.l3_size = '32MB'
+    # Keep 32MB as default, but don't override an explicit CLI value.
+    if not any(
+        opt.startswith("--l3-size") or opt.startswith("--l3_size")
+        for opt in sys.argv[1:]
+    ):
+        args.l3_size = '32MB'

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@configs/example/idealkmhv3.py` at line 145, The file currently
unconditionally overrides args.l3_size to '32MB', which discards any
user-provided --l3-size/--l3_size; change this to preserve CLI intent by either
(a) setting the default on the argument definition (use parser.add_argument(...,
default='32MB')) or (b) only assign the fallback when the value is absent (e.g.,
if getattr(args, 'l3_size', None) in (None, '', False): args.l3_size = '32MB').
Update the code around args.l3_size (or the parser.add_argument call that
defines it) so that explicit user values are not overwritten.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@configs/example/idealkmhv3.py`:
- Line 145: The file currently unconditionally overrides args.l3_size to '32MB',
which discards any user-provided --l3-size/--l3_size; change this to preserve
CLI intent by either (a) setting the default on the argument definition (use
parser.add_argument(..., default='32MB')) or (b) only assign the fallback when
the value is absent (e.g., if getattr(args, 'l3_size', None) in (None, '',
False): args.l3_size = '32MB'). Update the code around args.l3_size (or the
parser.add_argument call that defines it) so that explicit user values are not
overwritten.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 5ba12a7f-386b-4946-a5d2-1e9d41933ee8

📥 Commits

Reviewing files that changed from the base of the PR and between 4b6b1dc and f8e31c8.

📒 Files selected for processing (1)

• configs/example/idealkmhv3.py

[github-actions]

🚀 Coremark Smoke Test Results

Branch	IPC	Change
Base (xs-dev)	2.2665	-
This PR	2.2665	➡️ 0.0000 (0.00%)

✅ Difftest smoke test passed!