2019 EuroLLVM Developers’ Meeting: V. Bridgers & F. Piovezan “LLVM IR Tutorial - Phis, GEPs ...”

llvm.org/devmtg/2019-04/
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LLVM IR Tutorial - Phis, GEPs and other things, oh my! - Vince Bridgers (Intel Corporation), Felipe de Azevedo Piovezan (Intel Corporation)
Slides: llvm.org/devmtg/2019-04/slides...
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LLVM intermediate representation (IR) is the abstract description machine operations used to translate LLVM front ends to a form that's executable by a target machine. Optimizations and transformations are performed on the IR by the LLVM library to create executable images. This tutorial will introduce the IR syntax, describe basic tools for manipulating IR formats, and describe mappings of IR from various common source code control structures. Tutorial materials with specific examples will be made available for the tutorial presentation, and for offline review.
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Videos Filmed & Edited by Bash Films: www.BashFilms.com

[@miguelmuscat]

This is a big help. The lang ref and docs are kind of scary when you have no background info.
Now I feel like I can go in and read them with a lot less confusion. Thanks!

[@jort93z]

This is great. I have to write a small IR compiler(while having no idea what LLVM IR is) and this was of great help.

[@eopXD]

The presentation is well-designed for beginners.
Thank you for the tutorial!

[@Jan_Jan_]

Always find myself coming back to this talk. It's clear and concise! 👍

[@higuoxing]

Nice tutorial, but it seems that there's a small mistake in the example (13:20):
recursive_base should be
```
recursive_base:
%1 = add i32 -1, %val
%2 = call i32 @factorial(i32 %1)
%3 = mul i32 %val, %2
ret i32 %3
```

[@Felipe-nw3hx]

Yup, you're absolutely right :)

[@Felipe-nw3hx]

@Lovely Douche glad it helped!

[@ardenguo8682]

I was unsure and then found this reply!!! Nice

[@tomasvallejos1609]

I was looking to see if someone pointed that out, I wasn't sure if there was some obscure reason to have the indices on the right side of the asignation to be one less than on the left side haha

[@RafaeldeLucena]

Nice presentation, congrats!

[@osdthellogcchellollvm5290]

Thank. This is very helpful. Excellent tutorial.

[@shashanksharma21]

an excellent tutorial ! Thanks !!

[@omerguzel8351]

Nice and clear explaination. Thank you.

[@afgafa7336]

quite clear and organized

[@gabe.henrique]

Still fire!

[@cyrilemeka6987]

Thank you

[@abuyoyo31]

Is any of this changed by LLVM opaque pointers?

[@apivovarov2]

кто по ссылке from Konstantin Vladimirov?

[@KeithMakank3]

13:24 haha the IR is wrong, its supposed to return %3 not %2