Hacker News new | ask | show | jobs
by mathisfun123 1122 days ago
>PGO is an edge case and not used a whole lot in practice. Many compilers do not support it at all, even production compilers.

Both clang and gcc support `-fprofile-generate`. Beyond that generic infrastructure, in my area (DL compilers) if you're not doing PGO/autotuning you're not serious.

>Someone learning to write a compiler does not need to think about PGO.

That's like saying someone learning to write a compiler doesn't need to think about optimization at all - sure maybe the first time. But then every time after that it should be at the forefront of your mind.
1 comments
slavapestov 1122 days ago
> Both clang and gcc support `-fprofile-generate`. Beyond that generic infrastructure, in my area (DL compilers) if you're not doing PGO/autotuning you're not serious.

How many binaries in a typical Linux distro are built with PGO for example? The answer is approximately zero.

link
mathisfun123 1122 days ago
Your point? Because your first goalpost was "most compilers don't even support PGO". And now the goalpost is Linux distros? How about this one - how many binaries at FB/G are built with PGO? Answer: a great deal (llvm/bolt is a FB project and MLGO is a G project).
link
slavapestov 1122 days ago
My point is that the view of a compiler as a series of transformation passes from a source program to machine code, implemented as pure functions, is an entirely appropriate way to describe how they work in a random introductory blog post?

Congratulations on your recent PhD in quantum machine learning or whatever -- I hope you find some way to speed up FB/G's ad serving algorithms by 1% and land that promotion. I'm sure you're very smart.

link
mathisfun123 1122 days ago
>My point is that the view of a compiler...

Your point in bringing up Linux was to reiterate your original point? Interesting.

> I hope you find some way to speed up FB/G's ad serving algorithms by 1% and land that promotion. I'm sure you're very smart.

lol

link