ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
1–10 of 19 posts
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#2Relevant Rust discussion: https://www.reddit.com/r/rust/comments/4p4l5k/
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#3I didn't understand fully what it took to achieve this but simply looking at the numbers it is so clear how impressive the work is. Near or better performance with enormously fast build time, significant improvement in incremental compilation and enormous reduction in memory usage. Its unusual to see an optimization attempt succeed from so many different angle.
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#4There's a session from WWDC 2016 that talks about this - https://developer.apple.com/videos/play/wwdc2016/405/
The LTO part runs from 14:00 to 22:00. The streaming seems to only work in Safari (for Macs), but you can download the mp4s in HD (1.2 GB) or SD (300 MB).
They do a good job of describing how it works and why this is kind of a big deal.
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#5I didn't understand fully what it took to achieve this but simply looking at the numbers it is so clear how impressive the work is. Near or better performance with enormously fast build time, significant improvement in incremental compilation and enormous reduction in memory usage. Its unusual to see an optimization attempt succeed from so many different angle.
It's been in the works for quite a while (I remember reading some of the initial RFC postings), although I haven't seen people talk much of it until now. To be fair, I believe this work was primarily done by Google, who also have contributed a lot code to LTO/IPO-based systems in GCC before (such as "Lightweight IPO" or LIPO in GCC) as well as obvious, ongoing Clang/LLVM work. So I imagine they probably had a very good idea of what was necessary to achieve all that... But yes, the results are really impressive!
Here are some slides from EuroLLVM last year with some pretty graphs and comparisons to traditional LTO/LIPO: http://llvm.org/devmtg/2015-04/slides/ThinLTO_EuroLLVM2015.p...
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#6Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#7There's a session from WWDC 2016 that talks about this - https://developer.apple.com/videos/play/wwdc2016/405/ The LTO part runs from 14:00 to 22:00. The streaming seems to only work in Safari (for Macs), but you can download the mp4s in HD (1.2 GB) or SD (300 MB). They do a good job of describing how it works and why this is kind of a big deal.
For non-Safari-users, the download is hiding in the grayed-out "Resources" tab.
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#8Is all this functionality encoded within .o files or does it create a separate cache file or directory?
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#9Is it compatible with ccache?
Re: ThinLTO: Scalable and Incremental Link-Time Optimization for LLVM
#10There's a session from WWDC 2016 that talks about this - https://developer.apple.com/videos/play/wwdc2016/405/ The LTO part runs from 14:00 to 22:00. The streaming seems to only work in Safari (for Macs), but you can download the mp4s in HD (1.2 GB) or SD (300 MB). They do a good job of describing how it works and why this is kind of a big deal.
Interesting.
Google built it because it's pretty necessary to scale to the size application we build.
It looks like Apple started using it just because it's faster anyway ;)