Implement dual LUT scheme for int16 reciprocal/rsqrt operations

[3l1]

Summary:
Dual LUT Strategy

Reviewed By: digantdesai

Differential Revision: D87120925

[pytorch-bot]

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❌ 7 New Failures, 1 Cancelled Job, 1 Unrelated Failure

As of commit 20401cc with merge base dbf3c37 ():

NEW FAILURES - The following jobs have failed:

• Lint / lintrunner / linux-job (gh)
  >>> Lint for backends/arm/_passes/arm_pass_manager.py:
• Lint / lintrunner-mypy / linux-job (gh)
  >>> Lint for backends/arm/_passes/__init__.py:
• pull / unittest-arm-backend-with-no-deps (test_pytest_models_tosa) / linux-job (gh)
  RuntimeError: Command docker exec -t 1cb88edd787b155970675d70b048c9b86b56ff73e8dfbda6761fe47bc02e59e4 /exec failed with exit code 1
• pull / unittest-arm-backend-with-no-deps (test_pytest_ops_no_target) / linux-job (gh)
  RuntimeError: Command docker exec -t cf0ed3966bbd5f3e4771df22dc6379c6da6161929d6de2ca0cb2629e81af08d1 /exec failed with exit code 1
• pull / unittest-arm-backend-with-no-deps (test_pytest_ops_tosa) / linux-job (gh)
  RuntimeError: Command docker exec -t a64637ff4167d0699900a60354a75e100eb4d5a4f5d3d3ae0efd1a56b9a177b1 /exec failed with exit code 1
• pull / unittest-arm-backend-with-no-deps (test_run_tosa) / linux-job (gh)
  RuntimeError: Command docker exec -t 0b38bf6b417e17a6a57f6346fddcf9fd36cae53ce270f274ebf87c63661babd6 /exec failed with exit code 1
• Test CUDA Builds / test-model-cuda-e2e (google, gemma-3-4b-it, non-quantized) / linux-job (gh)
  RuntimeError: Command docker exec -t 173bce6abfea72c748afa9d7d932fb3d90843df6eda3e86607f87965af895671 /exec failed with exit code 1

CANCELLED JOB - The following job was cancelled. Please retry:

• pull / test-samsung-models-linux / linux-job (gh)
  ##[error]The operation was canceled.

UNSTABLE - The following job is marked as unstable, possibly due to flakiness on trunk:

• pull / android / run-emulator (gh) (#16137)
  Timeout waiting for emulator to boot.

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[meta-codesync]

@3l1 has exported this pull request. If you are a Meta employee, you can view the originating Diff in D87120925.

[digantdesai]

Review automatically exported from Phabricator review in Meta.

[3l1]

@pytorchbot label "release notes: none"

[3l1]

NOTE: I have pending changes before merging !!