Whenever I import numpy, I get a warning about division by 0 from /usr/lib/python3.11/site-packages/numpy/core/getlimits.py. This turns out to be because it's trying to figure out the precision of float16, but float16 does not seem to be working. It's possible to convert numbers to and from float16 (the conversion could be wrong, but it is at least bijective), but any attempt to do math with directly with float16 results in a 0. Python 3.11.5 (main, Oct 21 2023, 17:50:00) [GCC 12.3.1 20230526] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import numpy as np /usr/lib/python3.11/site-packages/numpy/core/getlimits.py:52: RuntimeWarning: divide by zero encountered in log10 self.precision = int(-log10(self.eps)) >>> np.float16(1.0) 1.0 >>> np.float16(1.0)+0.0 # operand is widened before addition 1.0 >>> np.float16(1.0)+np.float16(0.0) 0.0 >>> Reproducible: Always Steps to Reproduce: 1.in python on ppc64 (POWER9, big endian, in case it matters), import numpy 2. 3. Actual Results: numpy complains due to not being able to calculate the precision of float16. numpy contains a broken float16 class. Expected Results: No complaints from numpy. Either a working float16 class or none at all. Portage 3.0.51 (python 3.11.5-final-0, default/linux/ppc64/17.0/desktop, gcc-13, glibc-2.37-r7, 5.4.249 ppc64) ================================================================= System uname: Linux-5.4.249-ppc64-POWER9,_altivec_supported-with-glibc2.37 KiB Mem: 133525376 total, 59290560 free KiB Swap: 0 total, 0 free Timestamp of repository gentoo: Fri, 17 Nov 2023 17:00:01 +0000 Head commit of repository gentoo: 88485c0905b1c057025ed0d72010118a56203f44 Head commit of repository pike: 45ccd330ca143edc800640b3f87d430a17e9f7e0 Head commit of repository sawfish: bd1ce62b0af2428c55d379e826d34e69745b60f9 sh bash 5.1_p16-r6 ld GNU ld (Gentoo 2.40 p5) 2.40.0 app-misc/pax-utils: 1.3.7::gentoo app-shells/bash: 5.1_p16-r6::gentoo dev-java/java-config: 2.3.1-r1::gentoo dev-lang/perl: 5.38.0-r1::gentoo dev-lang/python: 3.11.5::gentoo, 3.12.0::gentoo dev-lang/rust: 1.71.1::gentoo dev-util/cmake: 3.27.7::gentoo dev-util/meson: 1.2.2-r1::gentoo sys-apps/baselayout: 2.14::gentoo sys-apps/openrc: 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sync-type: git sync-uri: git://pike-git.lysator.liu.se/pike-overlay.git masters: gentoo priority: 50 volatile: False sawfish location: /var/db/repos/sawfish-overlay sync-type: git sync-uri: https://gitlab.com/teika-gentoo/sawfish-overlay.git masters: gentoo priority: 90 volatile: False ACCEPT_KEYWORDS="ppc64" ACCEPT_LICENSE="@FREE" CBUILD="powerpc64-unknown-linux-gnu" CFLAGS="-O2 -pipe -mcpu=power9" CHOST="powerpc64-unknown-linux-gnu" CONFIG_PROTECT="/etc /usr/lib64/libreoffice/program/sofficerc /usr/share/config /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CXXFLAGS="-O2 -pipe -mcpu=power9" DISTDIR="/usr/portage/distfiles" EMERGE_DEFAULT_OPTS="--autounmask" ENV_UNSET="CARGO_HOME DBUS_SESSION_BUS_ADDRESS DISPLAY GDK_PIXBUF_MODULE_FILE GOBIN 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headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="karbon sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_PPC="altivec vsx vsx2 vsx3" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="libinput" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LUA_SINGLE_TARGET="lua5-1" LUA_TARGETS="lua5-1" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php8-1" POSTGRES_TARGETS="postgres15" PYTHON_SINGLE_TARGET="python3_11" PYTHON_TARGETS="python3_11" RUBY_TARGETS="ruby31" VIDEO_CARDS="fbdev radeon r600" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq proto steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: ADDR2LINE, AR, ARFLAGS, AS, ASFLAGS, CC, CCLD, CONFIG_SHELL, CPP, CPPFLAGS, CTARGET, CXX, CXXFILT, ELFEDIT, EXTRA_ECONF, F77FLAGS, FC, GCOV, GPROF, INSTALL_MASK, LC_ALL, LD, LFLAGS, LIBTOOL, LINGUAS, MAKE, MAKEFLAGS, NM, OBJCOPY, OBJDUMP, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, RANLIB, READELF, RUSTFLAGS, SIZE, STRINGS, STRIP, YACC, YFLAGS
Does not repro for me on stable clean chroot on BE...must be something flags-related or kernel maybe? Python 3.11.5 (main, Aug 28 2023, 05:57:37) [GCC 12.3.1 20230526] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import numpy as np >>> np.float16(1.0) 1.0 >>> np.float16(1.0) + 0.0 1.0 >>> np.float16(1.0) + np.float16(0.0) 1.0 >>> import platform ; platform.platform() 'Linux-6.6.1-gentoo-ppc64-ppc64-POWER9_-architected-,_altivec_supported-with-glibc2.37'
The full cflags during compilation are: -Inumpy/core/_multiarray_umath.cpython-311-powerpc64-linux-gnu.so.p -Inumpy/core -I../numpy-1.26.2/numpy/core -Inumpy/core/include -I../numpy-1.26.2/numpy/core/include -I../numpy-1.26.2/numpy/core/src/common -I../numpy-1.26.2/numpy/core/src/multiarray -I../numpy-1.26.2/numpy/core/src/npymath -I../numpy-1.26.2/numpy/core/src/umath -I/usr/include/python3.11 -I/tmp/portage/dev-python/numpy-1.26.2/work/numpy-1.26.2-python3_11/meson_cpu -fvisibility=hidden -fdiagnostics-color=always -Wall -Winvalid-pch -std=c99 -O3 -fno-strict-aliasing -mcpu=power9 -DNPY_HAVE_VSX -DNPY_HAVE_VSX_ASM -DNPY_HAVE_VSX2 -DNPY_HAVE_VSX3 -DNPY_HAVE_VSX3_HALF_DOUBLE -O2 -pipe -mcpu=power9 -fno-strict-aliasing -DNDEBUG -fPIC -DHAVE_CBLAS -DNPY_INTERNAL_BUILD -DHAVE_NPY_CONFIG_H -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE=1 -D_LARGEFILE64_SOURCE=1 Of this "-O2 -pipe -mcpu=power9" comes from my make.conf, the rest is generated by the make system. I'm wondering if the "-DNPY_HAVE_VSX3_HALF_DOUBLE" is perhaps a bad idea? My P9:s are DD2.2, btw. Python 3.11.5 (main, Oct 21 2023, 17:50:00) [GCC 12.3.1 20230526] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import platform ; platform.platform() 'Linux-5.4.249-ppc64-POWER9,_altivec_supported-with-glibc2.37' >>>
Try apply this patch? https://github.com/numpy/numpy/pull/25083
That patch is already included in 1.26.2, AFAICT.
I tried removing -DNPY_HAVE_VSX3_HALF_DOUBLE, but the behaviour is the same, so doesn't seem related...
OK, I got it. This shows up with -mcpu=power9, and only on BE (does not repro on LE even with -mcpu=power9). You can temporarily work around by removing -mcpu=power9 from CFLAGS. In the meantime I will report upstream.
I changed the cflags to say -mcpu=power8 for now, and that got me a working numpy (with VSX2 optimizations). Thanks.
The upstreams fix works for me. I just had to change "_core" to "core" in the path name for the patch to apply.
