https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101146
--- Comment #5 from Tomasz Kłoczko <kloczko.tomasz at gmail dot com> --- About strict aliasing: I need to check that (will back with results shortly) Here is short sctipt to produce binaries: CFLAGS='-O2 -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fdata-sections -ffunction-sections -flto=auto -flto-partition=none' CXXFLAGS='-O2 -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fdata-sections -ffunction-sections -flto=auto -flto-partition=none' FFLAGS='-O2 -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fdata-sections -ffunction-sections -flto=auto -flto-partition=none -I/usr/lib64/gfortran/modules' FCFLAGS='-O2 -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fdata-sections -ffunction-sections -flto=auto -flto-partition=none -I/usr/lib64/gfortran/modules' LDFLAGS='-Wl,-z,relro -Wl,--as-needed -Wl,--gc-sections -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -flto=auto -flto-partition=none -fuse-linker-plugin' CC=/usr/bin/gcc CXX=/usr/bin/g++ FC=/usr/bin/gfortran AR=/usr/bin/gcc-ar NM=/usr/bin/gcc-nm RANLIB=/usr/bin/gcc-ranlib export CFLAGS CXXFLAGS FFLAGS FCFLAGS LDFLAGS CC CXX FC AR NM RANLIB meson --buildtype=plain --prefix=/usr --libdir=/usr/lib64 --libexecdir=/usr/libexec --bindir=/usr/bin --sbindir=/usr/sbin --includedir=/usr/include --datadir=/usr/share --mandir=/usr/share/man --infodir=/usr/share/info --localedir=/usr/share/locale --sysconfdir=/etc --localstatedir=/var --sharedstatedir=/var/lib --wrap-mode=nodownload --auto-features=enabled . x86_64-redhat-linux-gnu -D build-tests=true -D cpp_std=gnu++14 -D dri3=enabled -D dri-drivers=nouveau,r100,r200,i915,i965 -D egl=enabled -D gallium-drivers=swrast,virgl,r300,nouveau,iris,svga,radeonsi,r600 -D gallium-nine=true -D gallium-omx=bellagio -D gallium-opencl=icd -D gallium-va=enabled -D gallium-vdpau=enabled -D gallium-xa=enabled -D gallium-xvmc=disabled -D gbm=enabled -D gles1=disabled -D gles2=enabled -D glvnd=true -D glx=dri -D llvm=enabled -D microsoft-clc=disabled -D opengl=true -D osmesa=true -D platforms=x11,wayland -D selinux=true -D shared-glapi=enabled -D shared-llvm=enabled -D valgrind=enabled -D vulkan-drivers=intel,amd meson compile -C x86_64-redhat-linux-gnu --verbose Compiler versiom: Any gcc produced in last yeear. Currently I was able to reporoduce that using last ninaries from fedora rawhide [tkloczko@barrel SPECS]$ gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/11/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-redhat-linux Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,objc,obj-c++,ada,go,d,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl=/builddir/build/BUILD/gcc-11.1.1-20210617/obj-x86_64-redhat-linux/isl-install --enable-offload-targets=nvptx-none --without-cuda-driver --enable-gnu-indirect-function --enable-cet --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 11.1.1 20210617 (Red Hat 11.1.1-5) (GCC) I just found that current mesa from fedora rawhide has didsabled LTO so to reporduce that issue you can use as well build env out of fedora rawhide packages and mesa package with commented line disabling LTO.
