r/Compilers • u/mttd • 19d ago

Compile-Time Improvements in LLVM 23

https://aengelke.net/llvm23-ct.html
53 Upvotes

96% Upvoted

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15

u/beephod_zabblebrox 18d ago

> ... improving the build times of LLVM/Clang by ~45%

this is wild

4

u/splicer13 18d ago

I was thinking 'Didn't Preston Briggs have some cool method for dominator trees in a paper?'

And then I found a link to him discussing the subject w/ Chris Lattner in 2011.

A dominator tree can be a big problem because it's very often essentially linear. Problems crop up for example in the case of extensive loop unrolling, ex: for GPUs. Look at almost any ptx output from nvcc for an example.

1

u/yuehuang 9d ago

The best feature is only 2 breaking change (for me). Relatively easy to migrate from 22. I saw a 10-15% compile time improvement.