I found two issues here: 1. build flags xxHash adds -O3 by itself, RPM adds -O2 after that. This results in binaries that are built with -O2, where -O3 is required for decent performance, which is why xxHash insists on building with -O3 in the first place. 2. DISPATCH=1 set on build, but not in install xxHash supports dynamic dispatching, i.e. using CPU-level dependant code, on x86_64. While this is enabled in xxhsum and libxxhash, there is no way to consume this feature, as the xxh_x86dispatch.h header is missing from xxhash-devel. Basically the "make install" also needs DISPATCH=1 to install the header. Reproducible: Always Steps to Reproduce: 1. Build a test-program consuming xxhash using the packages library 2. Build the same program using a bundled xxhash 3. Measure runtime of both programs Actual Results: Speed of 1. is two times slower than 2. Expected Results: Speed of the build from 1. should be in the ballpark of 2. I measured on an Intel i7-7820HQ. While -O3 doesn't provide huge gains if dispatching is enabled, it is probably worth having for non-x86 platforms.
I created a pull-request to package the headerfile. I currently have no idea how to fix the -O2 vs -O3 issue though.
FEDORA-2024-3e3e517b53 (xxhash-0.8.2-4.fc42) has been submitted as an update to Fedora 42. https://bodhi.fedoraproject.org/updates/FEDORA-2024-3e3e517b53
FEDORA-2024-3d8c04544c (xxhash-0.8.2-4.fc39) has been submitted as an update to Fedora 39. https://bodhi.fedoraproject.org/updates/FEDORA-2024-3d8c04544c
FEDORA-2024-e55072091c (xxhash-0.8.2-4.fc41) has been submitted as an update to Fedora 41. https://bodhi.fedoraproject.org/updates/FEDORA-2024-e55072091c
FEDORA-2024-3c4e7ae2ea (xxhash-0.8.2-4.fc40) has been submitted as an update to Fedora 40. https://bodhi.fedoraproject.org/updates/FEDORA-2024-3c4e7ae2ea
FEDORA-2024-3e3e517b53 (xxhash-0.8.2-4.fc42) has been pushed to the Fedora 42 stable repository. If problem still persists, please make note of it in this bug report.
FEDORA-2024-3c4e7ae2ea has been pushed to the Fedora 40 testing repository. Soon you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2024-3c4e7ae2ea` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2024-3c4e7ae2ea See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2024-3d8c04544c has been pushed to the Fedora 39 testing repository. Soon you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2024-3d8c04544c` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2024-3d8c04544c See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2024-e55072091c has been pushed to the Fedora 41 testing repository. Soon you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2024-e55072091c` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2024-e55072091c See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2024-3c4e7ae2ea (xxhash-0.8.2-4.fc40) has been pushed to the Fedora 40 stable repository. If problem still persists, please make note of it in this bug report.
FEDORA-2024-e55072091c (xxhash-0.8.2-4.fc41) has been pushed to the Fedora 41 stable repository. If problem still persists, please make note of it in this bug report.
FEDORA-2024-3d8c04544c (xxhash-0.8.2-4.fc39) has been pushed to the Fedora 39 stable repository. If problem still persists, please make note of it in this bug report.