[llvm-dev] New pass manager, documentation?

[via llvm-dev]

> For example, what is the rough equivalent to addPreISel() in the old one for running target specific passes shortly before instruction selection

Hello,

Code generation passes including target-specific IR passes (usually these specified in derived TargetPassConfig class) are not using the new pass manager.  I'm working on switching the code generation to use the new pass manager but it is not quite there yet. I guess we should document this fact in the new pass manager documentation because I think this question comes up once in a while.

- Yuanfang

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From: llvm-dev <llvm-dev-bounces at lists.llvm.org> on behalf of Jon Chesterfield via llvm-dev <llvm-dev at lists.llvm.org>
Sent: Wednesday, February 24, 2021 9:31 AM
To: llvm-dev
Subject: [llvm-dev] New pass manager, documentation?

Hi,

I'm trying to work out how to use the new pass manager. For example, what is the rough equivalent to addPreISel() in the old one for running target specific passes shortly before instruction selection, or how do I run a module pass shortly before a function pass.

I have a module pass which works if run shortly before instruction selection, but not if it is run via EP_ModuleOptimizerEarly. My current plan is to make the pass significantly more complicated, so that it can handle being run repeatedly from suboptimal points in the pipeline, but I can keep the simple/stupid version instead if I can work out how the pass manager works.

Thanks,

Jon