Test test_bfloat16_plus_float fails on s390x

[skriesch]

Summary

Our build fails for s390x because the numbers are not rounded enough:
tests/gtests/internals/test_bfloat16.cpp:79: Failure
[18667s] Expected: (float {expect_bf16}) > (float {initial_value_bf16}), actual: 0 vs 4.59163e-41

Version

3.6

Environment

oneDNN includes hardware-specific optimizations and may behave
differently on depending on the compiler and build environment. Include
the following information to help reproduce the issue:

• CPU make and model (try lscpu; if your lscpu does not list CPU flags,
  try running cat /proc/cpuinfo | grep flags | sort -u): s390x
• OS version (uname -a): openSUSE Tumbleweed
• Compiler version (gcc --version): gcc-14-2.1
• CMake version (cmake --version): cmake-3.31.0-1.1
• CMake output log:

/usr/bin/cmake /home/abuild/rpmbuild/BUILD/oneDNN-3.6/. '-GUnix Makefiles' -DCMAKE_INSTALL_PREFIX:PATH=/usr -DCMAKE_INSTALL_BINDIR:PATH=bin -DCMAKE_INSTALL_SBINDIR:PATH=sbin -DCMAKE_INSTALL_LIBEXECDIR:PATH=libexec -DCMAKE_INSTALL_SYSCONFDIR:PATH=etc -DCMAKE_INSTALL_SHAREDSTATEDIR:PATH=/var/lib -DCMAKE_INSTALL_LOCALSTATEDIR:PATH=var -DCMAKE_INSTALL_RUNSTATEDIR:PATH=run -DCMAKE_INSTALL_LIBDIR:PATH=lib64 -DCMAKE_INSTALL_INCLUDEDIR:PATH=include -DCMAKE_INSTALL_DATAROOTDIR:PATH=share -DCMAKE_INSTALL_DOCDIR:PATH=share/doc/packages/onednn -DCMAKE_INSTALL_MANDIR:PATH=share/man -DCMAKE_INSTALL_INFODIR:PATH=share/info -DINCLUDE_INSTALL_DIR:PATH=/usr/include -DLIB_INSTALL_DIR:PATH=/usr/lib64 -DSYSCONF_INSTALL_DIR:PATH=/etc -DSHARE_INSTALL_PREFIX:PATH=/usr/share -DCMAKE_BUILD_TYPE=RelWithDebInfo '-DCMAKE_C_FLAGS=-O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -g' '-DCMAKE_CXX_FLAGS=-O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -g' '-DCMAKE_Fortran_FLAGS=-O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -g' '-DCMAKE_EXE_LINKER_FLAGS=-flto=auto -Wl,--as-needed -Wl,--no-undefined -Wl,-z,now' '-DCMAKE_MODULE_LINKER_FLAGS=-flto=auto -Wl,--as-needed' '-DCMAKE_SHARED_LINKER_FLAGS=-flto=auto -Wl,--as-needed -Wl,--no-undefined -Wl,-z,now' -DLIB_SUFFIX=64 -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON -DBUILD_SHARED_LIBS:BOOL=ON -DBUILD_STATIC_LIBS:BOOL=OFF -DCMAKE_COLOR_MAKEFILE:BOOL=OFF -DCMAKE_INSTALL_DO_STRIP:BOOL=OFF -DCMAKE_MODULES_INSTALL_DIR=/usr/lib64/cmake/onednn -DCMAKE_INSTALL_LIBDIR=lib64 -DMKLDNN_ARCH_OPT_FLAGS= -DDNNL_CPU_RUNTIME=OMP -DDNNL_INSTALL_MODE=DEFAULT -DDNNL_BUILD_TESTS=ON -DONEDNN_BUILD_GRAPH=ON -DDNNL_WERROR=OFF
[ 2068s] CMake Deprecation Warning at CMakeLists.txt:17 (cmake_minimum_required):
[ 2068s]   Compatibility with CMake < 3.10 will be removed from a future version of
[ 2068s]   CMake.
[ 2068s] 
[ 2068s]   Update the VERSION argument <min> value or use a ...<max> suffix to tell
[ 2068s]   CMake that the project does not need compatibility with older versions.
[ 2068s] 
[ 2068s] 
[ 2070s] -- The C compiler identification is GNU 14.2.1
[ 2071s] -- The CXX compiler identification is GNU 14.2.1
[ 2071s] -- Detecting C compiler ABI info
[ 2074s] -- Detecting C compiler ABI info - done
[ 2074s] -- Check for working C compiler: /usr/bin/cc - skipped
[ 2075s] -- Detecting C compile features
[ 2075s] -- Detecting C compile features - done
[ 2075s] -- Detecting CXX compiler ABI info
[ 2077s] -- Detecting CXX compiler ABI info - done
[ 2078s] -- Check for working CXX compiler: /usr/bin/c++ - skipped
[ 2078s] -- Detecting CXX compile features
[ 2078s] -- Detecting CXX compile features - done
[ 2078s] -- DNNL_TARGET_ARCH: S390X
[ 2078s] -- DNNL_LIBRARY_NAME: dnnl
[ 2078s] -- Performing Test CMAKE_HAVE_LIBC_PTHREAD
[ 2082s] -- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
[ 2082s] -- Found Threads: TRUE
[ 2089s] -- Found OpenMP_C: -fopenmp (found version "4.5")
[ 2092s] -- Found OpenMP_CXX: -fopenmp (found version "4.5")
[ 2092s] -- Found OpenMP: TRUE (found version "4.5")
[ 2092s] -- Found Doxygen: /usr/bin/doxygen (found version "1.12.0") found components: doxygen dot
[ 2093s] -- Could NOT find Doxyrest (missing: DOXYREST_EXECUTABLE) 
[ 2093s] CMake Warning (dev) at cmake/Sphinx.cmake:25 (find_package):
[ 2093s]   Policy CMP0148 is not set: The FindPythonInterp and FindPythonLibs modules
[ 2093s]   are removed.  Run "cmake --help-policy CMP0148" for policy details.  Use
[ 2093s]   the cmake_policy command to set the policy and suppress this warning.
[ 2093s] 
[ 2093s] Call Stack (most recent call first):
[ 2093s]   cmake/doc.cmake:28 (include)
[ 2093s]   CMakeLists.txt:127 (include)
[ 2093s] This warning is for project developers.  Use -Wno-dev to suppress it.
[ 2093s] 
[ 2093s] -- Could NOT find PythonInterp (missing: PYTHON_EXECUTABLE) (Required is at least version "2.7")
[ 2093s] -- Could NOT find Sphinx (missing: SPHINX_EXECUTABLE) 
[ 2093s] -- Could NOT find Git (missing: GIT_EXECUTABLE) 
[ 2093s] -- Enabled testing coverage: CI
[ 2093s] -- Enabled workload: TRAINING
[ 2093s] -- Enabled primitives: ALL
[ 2093s] -- Enabled primitive CPU ISA: ALL
[ 2093s] -- Enabled primitive GPU ISA: ALL
[ 2093s] -- Enabled GeMM kernels ISA: ALL
[ 2093s] -- Primitive cache is enabled
[ 2093s] -- Graph component is enabled
[ 2093s] -- Graph compiler backend is disabled.
[ 2097s] -- Configuring done (29.2s)
[ 2101s] -- Generating done (4.5s)
[ 2101s] CMake Warning:
[ 2101s]   Manually-specified variables were not used by the project:
[ 2101s] 
[ 2101s]     BUILD_STATIC_LIBS
[ 2101s]     CMAKE_Fortran_FLAGS
[ 2101s]     CMAKE_INSTALL_DO_STRIP
[ 2101s]     CMAKE_MODULES_INSTALL_DIR
[ 2101s]     INCLUDE_INSTALL_DIR
[ 2101s]     LIB_INSTALL_DIR
[ 2101s]     LIB_SUFFIX
[ 2101s]     MKLDNN_ARCH_OPT_FLAGS
[ 2101s]     SHARE_INSTALL_PREFIX
[ 2101s]     SYSCONF_INSTALL_DIR
[ 2101s] 

• git hash (git log -1 --format=%H)

Steps to reproduce

Build with openSUSE via OBS with tar archive.
-> build error with:

----------] 1 test from test_bfloat16_plus_float
[18667s] [ RUN      ] test_bfloat16_plus_float.TestDenormF32
[18667s] /home/abuild/rpmbuild/BUILD/oneDNN-3.6/tests/gtests/internals/test_bfloat16.cpp:79: Failure
[18667s] Expected: (float {expect_bf16}) > (float {initial_value_bf16}), actual: 0 vs 4.59163e-41
[18667s] [  FAILED  ] test_bfloat16_plus_float.TestDenormF32 (0 ms)
[18667s] [----------] 1 test from test_bfloat16_plus_float (0 ms total)

Observed behavior

Failed build on openSUSE for s390x because of missing rounding.

Expected behavior

Successful build on s390x without test failures.

[uweigand]

@Andreas-Krebbel is this something we've already seen or where we could help?