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Lanai, the mystery CPU architecture in LLVM

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Re: Lanai, the mystery CPU architecture in LLVM

#11
post #8
post #6

Earlier quoted context omitted.

The fact that they developed and upstreamed an LLVM backend indicates that they probably did something with it.

The Google way: Force the rest of the world adjust to your new "cool thing", and then kill it because it wasn't that great.

Google isn't really forcing anyone to do anything in this case. Another RISC backend that was made clear would be ripped out of upstream the instant the Google maintainers stopped responding isn't really an imposition.

Re: Lanai, the mystery CPU architecture in LLVM

#12
post #4

I worked for Myricom 2001->2013, and Google 2013->2015. And, wow, I wish I could comment on this thread.. :) EDIT: Scott's Medium blog post linked from this article is fascinating: https://medium.com/swlh/myricom-an-hpc-story-and-lessons-lea...

Why can you not comment? Certainly any NDA you signed must be expired by now.

PSA: If you are not getting continuing payments, any contracts you signed are void. Technically, I gather you are supposed to notify the other party that you are terminating your participation in the contract. Even if you are getting ongoing payments, you can opt out of that, too.

(This is not legal advice. Consult an actual lawyer for anything that matters.)

Re: Lanai, the mystery CPU architecture in LLVM

#14
post #8

Earlier quoted context omitted.

The Google way: Force the rest of the world adjust to your new "cool thing", and then kill it because it wasn't that great.

Google isn't really forcing anyone to do anything in this case. Another RISC backend that was made clear would be ripped out of upstream the instant the Google maintainers stopped responding isn't really an imposition.

Would something like this be accepted in open source projects that are not significantly driven by Google?

E.g. would Linux accept code for drivers / architectures that are not available to the public? I'm genuinely curious.

Re: Lanai, the mystery CPU architecture in LLVM

#15
post #8

Earlier quoted context omitted.

The Google way: Force the rest of the world adjust to your new "cool thing", and then kill it because it wasn't that great.

Google isn't really forcing anyone to do anything in this case. Another RISC backend that was made clear would be ripped out of upstream the instant the Google maintainers stopped responding isn't really an imposition.

The relevant discussion: https://lists.llvm.org/pipermail/llvm-dev/2016-February/0951...

Seems the maintainers were more than happy to accept it, and even had policies in place for such contributions. One maintainer even mentioned it's a good policy because it brings more developers into using LLVM's ToT, which is overall good for project health.

Re: Lanai, the mystery CPU architecture in LLVM

#16
I gotta say, if I was the BDFL of llvm, I would kick this out of tree without a second thought. Why on earth should a foss project support a private architecture? How many man-hours have been wasted waiting for the Lanai backend to compile? Not to mention applying project-wide refactoring to the Lanai code.

Re: Lanai, the mystery CPU architecture in LLVM

#17
post #4

I worked for Myricom 2001->2013, and Google 2013->2015. And, wow, I wish I could comment on this thread.. :) EDIT: Scott's Medium blog post linked from this article is fascinating: https://medium.com/swlh/myricom-an-hpc-story-and-lessons-lea...

I just want to know why it needs to be in-tree.

Google uses upstream llvm as their dev repo. I don't know if they do any development downstream.

Re: Lanai, the mystery CPU architecture in LLVM

#18
> Some of my recent long-term projects revolve around a little known CPU architecture called 'Lanai'. Unsurprisingly, very few people have heard of it, and even their Googling skills don't come in handy.

I don't get this. Searching for [lanai cpu] shows tons of links on the LANai cpu architecture from Myricom, purchased by Google.

Re: Lanai, the mystery CPU architecture in LLVM

#20
post #5
post #4

I worked for Myricom 2001->2013, and Google 2013->2015. And, wow, I wish I could comment on this thread.. :) EDIT: Scott's Medium blog post linked from this article is fascinating: https://medium.com/swlh/myricom-an-hpc-story-and-lessons-lea...

Yeah, that blog post was a great reference to get a general overview of What Happened At Myricom. ... and I just hope I didn't write anything factually wrong in TFA. :)

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