GCC 15 - LLVM Clang 20 Compiler Performance comparison

[Grenzschutzeinheit]

In the actual GCC 15 vs. LLVM Clang 20 Performance On AMD Zen 5 Article on Phoronix there are several Benchmarks where the llvm 20 preview is slower then llvm 19 and / or GCC 15 preview on AMD EPYC 9575F with "-O3 -march=native -flto".

Examples.:

• srsRAN Project 24.10
• 7-Zip Compression/Decompression
• Stargate Digital Audio Workstation
• Liquid DSP
• Llama.cpp
• Quicksilver OpenMP HPC benchmark

[asl]

In general it is ok that in some benchmarks gcc shows better result.

The following though worth looking as it might be a real regression:

[Grenzschutzeinheit]

In general it is ok that in some benchmarks gcc shows better result.

The following though worth looking as it might be a real regression:

How can i help to fix this?
@adibiagio i saw you analyzed past Regressions, can you Help?

[umbrageodotus]

Any updates?!

[adworacz]

Just a note Zen 5 still hasn’t been tuned for, and sounds like even Zen 4 might be using outdated numbers

#131780

[NexusXe]

Yes, Zen 5 currently doesn't have its own tuning data. Zen 4's numbers have been updated since the comment was made on that PR.