Dear maintainer, xsimd provides a unique API for SIMD instructions among different processor architectures. Additionally to many specific architectures, there is also a fallback scalar option for unsupported architectures (as far as I interpret the headers). Currently, xsimd-dev fails to build on armel, armhf, mips64el, mipsel, ppc64el, s390x (armhf is built with 8.0.3-1 on experimental). xsimd-dev is build dependency of pythran, which makes pythran uninstallable on the platforms where xsimd-dev fails. In turn, python3-pythran is a new build dependency of skimage (0.19.2). The current version of skimage (0.18.3) is now starting to collect RC bugs because of incompatibilities with newer pil and tifffile versions (#1009431, #1010430). skimage is also one of the basic scientific Python packages which is expected to be available on all platforms. Therefore, could I ask to provide xsimd-dev for all platforms, using the scalar fallback for unsupported CPUs? Best regards Ole
Hi Ole, I've looked at the code of xsimd 8, and it seems that the fallback has been replaced by another mechanism; however my tests on a mipsel porterbox fail to compile simple programs. I've taken the issue upstream (https://github.com/xtensor-stack/xsimd/issues/756) to see what is the status of the fallback mechanism. Cheers,
Hi again, To sum up upstream's answer [1]: xsimd does not support a fallback mechanism anymore, and pythran should work fine without xsimd. On the ARM side, armel is not supported, as xsimd requires __ARM_ARCH >= 7 [2]. The only solution I see is to package xsimd 8.1.0 and restrict it to amd64, arm64, armhf and i386: this is what I just commited to salsa. Let me know if you have a better solution, otherwise I'll upload the version currently in salsa to unstable. [1] https://github.com/xtensor-stack/xsimd/issues/756#issuecomment-1142521979 [2] https://github.com/xtensor-stack/xsimd/blob/8.1.0/include/xsimd/config/xsimd_config.hpp#L247-L273 Cheers,
We believe that the bug you reported is fixed in the latest version of xsimd, which is due to be installed in the Debian FTP archive. A summary of the changes between this version and the previous one is attached. Thank you for reporting the bug, which will now be closed. If you have further comments please address them to 1010595@bugs.debian.org, and the maintainer will reopen the bug report if appropriate. Debian distribution maintenance software pp. Julien Lamy <lamy@unistra.fr> (supplier of updated xsimd package) (This message was generated automatically at their request; if you believe that there is a problem with it please contact the archive administrators by mailing ftpmaster@ftp-master.debian.org) Format: 1.8 Date: Fri, 03 Jun 2022 16:37:16 +0200 Source: xsimd Architecture: source Version: 8.1.0-1 Distribution: unstable Urgency: medium Maintainer: Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org> Changed-By: Julien Lamy <lamy@unistra.fr> Closes: 1010595 Changes: xsimd (8.1.0-1) unstable; urgency=medium . [ Ileana Dumitrescu ] * New upstream version 8.0.5 * updated changelog . [ Julien Lamy ] * New upstream version 8.1.0 * Restrict to officially supported architectures (Closes: #1010595) Checksums-Sha1: b6bf6092f3bfc0d2e9cc67084e0ed617e3b183cc 2217 xsimd_8.1.0-1.dsc 526b474b7d37673f08e7ab8838bc39d16c77fd88 190180 xsimd_8.1.0.orig.tar.gz b41d75a96e5c13a16b571cfb077ffe3998d2edca 3996 xsimd_8.1.0-1.debian.tar.xz fd80c3f9ec4caa1e7d583efe31c94ff24feede1e 10443 xsimd_8.1.0-1_amd64.buildinfo Checksums-Sha256: 8f1ecdeba7a723e86e8aa305e085eb73a969e221b77bd9c44bd3e40abbafcae3 2217 xsimd_8.1.0-1.dsc d52551360d37709675237d2a0418e28f70995b5b7cdad7c674626bcfbbf48328 190180 xsimd_8.1.0.orig.tar.gz 48a29de3fcda86eb5950b9b4c49839a41ad78b86b45a4075e3170b7c5d56ae1d 3996 xsimd_8.1.0-1.debian.tar.xz ce7818e2c37f924ed2b6fe2d041d52e3074cb89f3b3820b5c78f03ba48baa6e6 10443 xsimd_8.1.0-1_amd64.buildinfo Files: ef63b3cfd84c2524d6a210ccee4f87ec 2217 science optional xsimd_8.1.0-1.dsc e3edf90fcdf1d11297ed74bda96d7fbd 190180 science optional xsimd_8.1.0.orig.tar.gz 863ac8a11543cf05e7b8a0d005cd51f6 3996 science optional xsimd_8.1.0-1.debian.tar.xz 0a1fc03c6aa4cfc7e8d86316158e7855 10443 science optional xsimd_8.1.0-1_amd64.buildinfo -----BEGIN PGP SIGNATURE----- iQJEBAEBCAAuFiEEi90BMIDpoOjA1qFXOzZd6T69HNQFAmKrKgAQHGxhbXlAdW5p c3RyYS5mcgAKCRA7Nl3pPr0c1HyHD/4r2OmLFlVkg1ne38J/cPDd0pW0Hg+zNvqn gYRO1+7AFarAioLQJoNR3aQK+NQxc+HacodF2wljtKI94qtqjtlHaIx8MMAUhprh mo5x7+LGyo5Egtaw+jVf1pU8wuJ+V5HAxPDPpjUF+eYOpNbYpRFSRLo5mIuu0n2b QrgnhyeKTPIuOs3gooVCZ3kLo1kD+2RQBzzK0JRW7gp5u2T6k5W2CCXtbkb0DDd0 PuNflz5B3vZyC8scXkajCVQATcI5ANIFeJuG1jZuTYB9iMZSV9Zdv0BjOPU3b3fm Gwfv5TAV1uPm9rQ2w3Mgm5gWh07Wxh67sJjbkFOmx8lR/cgw8kfk0vs03DoZ0gvP R1x3x1guyc81n/kk65l9MvPLOvNzJ/Ig1jPz9rvc4br2BAecTQutsP/XCCUUZ+IW hlLWXKmjg8ZaK3tuKqXkb/IFhHe+acP15JcwLF0y+ixHj8lInCqYSivibghY211X exx5eC6LE9BP30T++2wvAJL0Uwe/djw81Z1Jew3ZkZv1uKKrFJbW34pIi/7BdUFO S6zjAm7BujkBLq3etaap//uZK70p8HONZm/qyCFFsgzqVSD/eHKCGhmdLdkzIcwh QXpwn+CF60b5Wl/zD4Q9V/ZJ3mLTW+qh5Fq5Zh7dhZAzRbW6dgAyAoumcbQfzSdq eTc95mgKSw== =7gKy -----END PGP SIGNATURE-----
A number of upgrades including scipy got interrupted by the upgrade of xsimd to v8. We're working through the transition now. scipy needs a working pythran but pythran needs xsimd available on all arches, even those without specific vector acceleration hardware (in which case xsimd scalar mode is used). We need to reconfigure xsimd tests to not attempt vector-mode functionality on unsupported arches.
I don't know myself which xsimd test is which in order to implement the scalar test division discussed in upstream Issue#756. For sure upstream will know. While we're resolving that, one simple thing we could do temporarily for the packaging is to restrict the CI tests to only run on the known vector-supported arches. This can be done with just an Architecture: field added to the Test entries in debian/tests/control. e.g. could copy the restricted Architecture line from debian/control over to the two tests in debian/tests/control, and then update debian/control to Architecture: any. Drew
We believe that the bug you reported is fixed in the latest version of xsimd, which is due to be installed in the Debian FTP archive. A summary of the changes between this version and the previous one is attached. Thank you for reporting the bug, which will now be closed. If you have further comments please address them to 1010595@bugs.debian.org, and the maintainer will reopen the bug report if appropriate. Debian distribution maintenance software pp. Julien Lamy <lamy@unistra.fr> (supplier of updated xsimd package) (This message was generated automatically at their request; if you believe that there is a problem with it please contact the archive administrators by mailing ftpmaster@ftp-master.debian.org) Format: 1.8 Date: Mon, 27 Jun 2022 06:58:27 +0200 Source: xsimd Architecture: source Version: 8.1.0-4 Distribution: unstable Urgency: medium Maintainer: Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org> Changed-By: Julien Lamy <lamy@unistra.fr> Closes: 1010595 Changes: xsimd (8.1.0-4) unstable; urgency=medium . * Reintroduce build on all arches (Closes: #1010595) * Run autopkgtests on supported architectures only Checksums-Sha1: 6129824fa51fcbdbeda8cbee4945a320f1f6b8c3 2190 xsimd_8.1.0-4.dsc bce7a4aee9718c0158c5009ff35d7ff864fa3724 6680 xsimd_8.1.0-4.debian.tar.xz cf2c573ecd1b2a014792019715aaf2a8a92fb198 10410 xsimd_8.1.0-4_amd64.buildinfo Checksums-Sha256: febcfb7a5cb94c94b89fd2c5d831d332f28504ecd76242c0f93f5bccc993b9d9 2190 xsimd_8.1.0-4.dsc 413215511e8c5bf139811d8078fac535a0a541c0ff4a5e8e302cce628cf79037 6680 xsimd_8.1.0-4.debian.tar.xz 738d67b8c561ecb38ecf6297f93f82ece2f1ef2bfc3abdf558d26c38166667ab 10410 xsimd_8.1.0-4_amd64.buildinfo Files: 8b92d8325fcd4df75d9ff4ef759a8ea6 2190 science optional xsimd_8.1.0-4.dsc 4d2924e86106f20f3cf422ba47bdb04c 6680 science optional xsimd_8.1.0-4.debian.tar.xz 62013d7cbbcb319fd734671c7a74cba6 10410 science optional xsimd_8.1.0-4_amd64.buildinfo -----BEGIN PGP SIGNATURE----- iQJEBAEBCAAuFiEEi90BMIDpoOjA1qFXOzZd6T69HNQFAmK5iAMQHGxhbXlAdW5p c3RyYS5mcgAKCRA7Nl3pPr0c1LGAD/wPLn/yQ/o72wYkNYF6sMidKar1x11VxzoP FMTjZ70dDDzyKzG81Z0Yr+hQincDiZZ6HHPCmEUj9BoZxB3uBkbQYxd2qBubLAdl 9iLL7qgPEWQFPNPDq3DIdiue1A60QbMXlyVNUsxBD0n2CQsFNJPWSR/PrFTioApF Bz/0LmuOf0vcy/a2Umj2rB3kVv0EnfR7pounKnMP2mtJRyCoQcjUeLbOKkXlfWeO Qx/0OKvwdZnvopC1PtwCzbTmFQr8YiXpWlbyuNQanb0wjoenndNWXIAeNeLMegkt zbh9O95tk57q7OIkQLf69ZVJj8znGrmbLXk7eBVEJoycNwgNSJG9haZ7NWh0OXaM 5hBPixz8c9sju1bYG0cPHO64KsvPPUEsuG5vdDJrAfYwxqwcXMsXdhlfyDAl2BQj AWQmYpE0T5BrR3rFCjKXYfRvAyLhfUXaJRE4+1YUf/0PQWyuudPsfid/puCjE2np GoQPpI3E/+zipA1UkNz8er4khhzNKKcyIh9Zy9qoptbEyLgeX8nuj5Hkx30X4Msw Ebz11AHHvLc/G/g7E8YJq3FnJZ8VRWYAofttDhftqrUdxnNWf7NV4JNDwDygpM8B jBKdc0txOt7Ujadzz1JHeAgtscdIuZEO7BFzpfmqLPm+E9qqNshVHcox9x5mh8Ya +6k0+HnFOA== =TKD/ -----END PGP SIGNATURE-----