[DOC][Tutorial] How to write a pass in python

[ehsanmok]

@tqchen As part of roadmap v0.4, I'd like to write a tutorial on how to write a pass in python, but I'll need to know more details. Could you point me where to look for and what the goals are more specifically?

[tqchen]

@were @ZihengJiang may have more suggestions to provide. The goal is to understand how to do low level IR transformations, and related python function to do so.

Doing so a simple example task, like(mark a serial loop as parallel), or replace a pattern with intrinsic, would be a useful thing

[tqchen]

also cc @xqdan @libing4752

[tqchen]

@were would you be interested in this?

[were]

@tqchen What do you mean by a "pass"? I have some experience in using IRTransformer and IRPostOrderVisitor, so I think I can do this?

[tqchen]

pass means transformations between IRs, so these are approperiate @were

[were]

OK. Then essentially, what we want on the tutorial becomes how to gather information via IR and how to transform the IR.

[were]

Where is a good place to put this tutorial?
If no suggestions, I will put it in tutorial/language.

[were]

I have written one #1671, but it is still crashing when building docs. Anyone can help?

[were]

Since #1671 is merged, should we close this issue?

[tqchen]

Thanks to @were , this is closed by #1671