[CodeGen] Refactor MachineInstr findRegisterDefOperandIdx/findRegisterDefOperand etc. to stop missing TRI args

[RKSimon]

As noticed by @AtariDreams on #82411, by having the TargetRegisterInfo argument at the end of a long line of optional args, we are often missing it in our function calls and not correctly testing for super reg kill state etc.

  int findRegisterUseOperandIdx(Register Reg, bool isKill = false, const TargetRegisterInfo *TRI = nullptr) const;
  MachineOperand *findRegisterUseOperand(Register Reg, bool isKill = false, const TargetRegisterInfo *TRI = nullptr);
  ... etc ...

ideally we need to refactor the calls so the TRI is no longer optional, so when we don't care about super-registers we explicitly have to set it nullptr.

  int findRegisterUseOperandIdx(Register Reg, const TargetRegisterInfo *TRI, bool isKill = false) const;
  MachineOperand *findRegisterUseOperand(Register Reg, const TargetRegisterInfo *TRI, bool isKill = false);
  ... etc ...

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. In the comments of the issue, request for it to be assigned to you.
2. Fix the issue locally.
3. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
4. Create a Git commit.
5. Run git clang-format HEAD~1 to format your changes.
6. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: Simon Pilgrim (RKSimon)

As noticed by @AtariDreams on #82411, by having the TargetRegisterInfo argument at the end of a long line of optional args, we are often missing it in our function calls and not correctly testing for super reg kill state etc.

  int findRegisterUseOperandIdx(Register Reg, bool isKill = false, const TargetRegisterInfo *TRI = nullptr) const;
  MachineOperand *findRegisterUseOperand(Register Reg, bool isKill = false, const TargetRegisterInfo *TRI = nullptr);
  ... etc ...

ideally we need to refactor the calls so the TRI is no longer optional, so when we don't care about super-registers we explicitly have to set it nullptr.

  int findRegisterUseOperandIdx(Register Reg, const TargetRegisterInfo *TRI, bool isKill = false) const;
  MachineOperand *findRegisterUseOperand(Register Reg, const TargetRegisterInfo *TRI, bool isKill = false);
  ... etc ...

[simonzgx]

Hi! I am new to the LLVM project, and I would like to take this issue. Could anyone please assign this issue to me?

[RKSimon]

@simonzgx Please keep an eye on #82411 as @AtariDreams is adding explicit TRI to several locations to address some implicit bugs - its likely that patch will land first so you may have to rebase a large number of conflicts

[simonzgx]

@RKSimon Got it.

[RKSimon]

@simonzgx #82411 has stalled due to test coverage issues, so if you are able to get your patch updated we might be able to get it in before it.

[simonzgx]

@RKSimon Okay, will do it pretty soon.

[simonzgx]

Hi @RKSimon ! As it mentioned, I submitted a new PR(#85968) and ready to be reviewed, please have a look.