What problem does it solve? When a PyPTO operator's output deviates from its PyTorch golden reference, developers struggle to locate which op, Pass, or codegen stage introduced the numerical error. This Skill provides a structured decision tree and three complementary comparison methods to pinpoint the exact source of precision divergence on Ascend NPU. ## Core Features & Use Cases - Tensor Graph Verification: Configures verify_options and set_verify_golden_data to detect frontend graph construction errors before deeper debugging. - Three Localization Methods: File-based checkpoint comparison (pypto.pass_verify_save + torch.save), Pass-level PreCheck/PostCheck validation with pass_compare.py, and on-device binary search using checkpoint tensors injected into kernel signatures. - Sync and VF Fusion Diagnosis: Includes scripts to bisect CCE files with pipe_barrier insertion and map failing lines back to frontend source code. - Use Case: An Add operator's NPU output mismatches torch.add results; the Skill walks through tensor_graph verification, then routes to the appropriate sub-method to find the first failing op. ## Quick Start Ask the assistant to debug a PyPTO operator precision issue using this skill, optionally specifying a mode such as file-save comparison, Pass verification, or on-device binary search.