Arm backend: Avoid running passes with no matching target ops

[YufengShi-dudu]

Add ArmPass.should_run_pass() as a reusable early-exit hook before
call() starts the normal ExportPass retracing path. The default hook
returns true, preserving existing behavior for ArmPass subclasses.

Introduce ArmOpTargetedPass for passes that only transform a known
set of operator targets. It implements should_run_pass() by scanning
the current graph and nested GraphModules for matching target
operators. If no matching target operator is found, the pass returns
an unmodified PassResult.

For passes that already gate transformations with
allowed_to_transform(), allow the target pre-scan to apply the same
check before deciding whether the pass needs to run. This avoids
running TFA passes when all matching target nodes are marked as
disallowed.

The should_run_pass() hook and ArmOpTargetedPass pre-scan avoid
rebuilding graphs for decomposition and rewrite passes that cannot
affect the current graph. The speedup is most visible on large models.

Single-run paired benchmarks on Arm backend model tests
across FP32, INT, VGF no-quant, and VGF quant variants:

Model	E2E avg	Pass-manager avg
T5-small	+30.5%	+47.5%
DeepLabV3	+12.9%	+49.8%
Wav2Letter	+16.9%	+51.2%
InceptionV3	+22.2%	+46.5%
MobileNetV2	+22.2%	+52.5%
MobileNetV3	+29.9%	+54.6%

Model rows are unweighted averages over successful variants.
Unweighted average across 23 successful model/target variants:
E2E speedup: +22.4%
Pass-manager speedup: +50.5%

Change-Id: Iaa09638473a1d6d1e2ce98f5a0e3fc3a14378143

cc @digantdesai @freddan80 @per @zingo @oscarandersson8218 @mansnils @Sebastian-Larsson @robell @rascani

[pytorch-bot]

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• /easycla is not responding

❌ 1 New Failure, 3 Unrelated Failures

As of commit d22f5c1 with merge base acce7cd ():

NEW FAILURE - The following job has failed:

• pull / test-multimodal-linux (gemma3-4b) / linux-job (gh)
  RuntimeError: Command docker exec -t 72d8768ecc49ed5fd9ed6461a70edb92f1c42ec769369467f7fd32885a5e712f /exec failed with exit code 139

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest-editable / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• trunk / unittest-release / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.

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[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Erik-Lundell / name: Erik Lundell (920dc9d)
• ✅ login: YufengShi-dudu / name: Yufeng Shi (920dc9d)

[YufengShi-dudu]

@claude Please find the email address that causes the unknown commit author error

[claude]

Claude finished @YufengShi-dudu's task in 1m 37s —— View job

---

Finding the problematic commit email

• Check the commit that causes the EasyCLA error
• Report the email address

The problematic email is per.astrand@arm.com from the co-author trailer in commit 2b16e08:

Co-authored-by: Per Åstrand <per.astrand@arm.com>

The EasyCLA bot successfully resolved:

• ✅ yufeng.shi@arm.com → GitHub user YufengShi-dudu
• ✅ erik.lundell@arm.com → GitHub user Erik-Lundell
• ❌ per.astrand@arm.com → not linked to any GitHub account

To fix this, either:

1. Per Åstrand needs to add per.astrand@arm.com to their GitHub account (user per based on the CC list), or
2. Update the co-author line to use their GitHub noreply email, e.g.:

   Co-authored-by: Per Åstrand <per@users.noreply.github.com>
   

3. Or remove the Co-authored-by line if Per's contribution doesn't need to be attributed in this commit.

---

[YufengShi-dudu]

3. Or remove the Co-authored-by line if Per's contribution doesn't need to be attributed in this commit.

@claude How can I remove the Per's Co-authored-by line? Do I need to push a new commit?

[claude]

Claude finished @YufengShi-dudu's task in 24s —— View job

---

Removing the Co-authored-by line

• Understand the request
• Provide instructions

You don't need a new commit — you need to amend the existing commit to remove the line, then force push. Here's how:

If the problematic commit is the latest one:

git commit --amend

This opens your editor. Delete the Co-authored-by: Per Åstrand <per.astrand@arm.com> line, save, and exit. Then:

git push --force origin avoid-running-nonmatching-target-op-passes

If the problematic commit is NOT the latest one (e.g., it's 2b16e08 and there are commits after it):

git rebase -i 2b16e08^

In the editor, change pick to edit for commit 2b16e08, save and exit. Then:

git commit --amend

Remove the Co-authored-by line, save, then continue the rebase:

git rebase --continue
git push --force origin avoid-running-nonmatching-target-op-passes

After force pushing, comment /easycla on the PR to re-trigger the CLA check.

---

[oscarandersson8218]

New file test_arm_op_targeted_pass.py should be covered by glob in targets.bzl. Should be OK to merge.