LTO in Rust produces multiple definition of `rust_eh_personality' (and
few others), and to overcome this --allow-multiple-definition has been
added.
Query for benchmark:
SELECT ignore(BLAKE3(materialize('Lorem ipsum dolor sit amet, consectetur adipiscing elit'))) FROM numbers(1000000000) FORMAT `Null`
upstream : Elapsed: 2.494 sec. Processed 31.13 million rows, 249.08 MB (12.48 million rows/s., 99.86 MB/s.)
upstream + rust lto: Elapsed: 13.56 sec. Processed 191.9 million rows, 1.5400 GB (14.15 million rows/s., 113.22 MB/s.)
llvm BLAKE3 : Elapsed: 3.053 sec. Processed 43.24 million rows, 345.88 MB (14.16 million rows/s., 113.28 MB/s.)
Note, I thought about simply replacing it with BLAKE3 from LLVM, but:
- this will not solve LTO issues for Rust (and in future more libraries
could be added)
- it makes integrating_rust_libraries.md useless (and there is even blog
post)
So instead I've decided to add this quirk (--allow-multiple-definition)
to fix builds.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>