[llvm] [TableGen] Use bitwise operations to access HwMode ID. (PR #88377)

[via llvm-commits]

superZWT123 wrote:

Hi @nvjle , I'm really sorry for the delay in addressing your review feedback. This update includes the following five main changes:

1. Fixed the issue with improper HwMode retrieval during Encoding generation process (the most critical issue).
2. Used encoding '0' to represent instructions with mismatched HwMode in the encoding table.
3. Added testcase to assess instruction encoding under APInt mode (128-bit length) and introduced more HwModes to validate performance under multiple HwMode scenarios.
4. Discovered and resolved a potential issue (not introduced by my patch) where the existing 'getOperandBitOffset' interface was checking HwMode ID without first retrieving it.
5. Made some modifications related to Clean Code and also fixed the comments.

Could you please review these changes again and verify them in your backend? Thank you very much!

https://github.com/llvm/llvm-project/pull/88377