On Wed, Jun 12, 2024 at 01:55:20PM +0300, Alexander Monakov wrote: > Hello, > > I'm sending straightforward reverts to recent patches that bumped minimum > required x86 instruction set to SSE4.2. The older chips did not stop working, > and people still test and use new software on older hardware: > https://sourceware.org/bugzilla/show_bug.cgi?id=31867 > > Considering the very minor gains from the baseline raise, I'm honestly not > sure why it happened. It seems better to let distributions handle that.
Indeed distros are opinionated about the x86_64 baseline they want to target. While RHEL-9 switched to a x86_64-v2 baseline, Fedora has repeatedly rejected the idea of moving to an x86_64-v2 baseline, wanting to retain full backwards compat. So this assumption in QEMU is preventing the distros from satisfying their chosen build target goals. > Alexander Monakov (5): > Revert "host/i386: assume presence of POPCNT" > Revert "host/i386: assume presence of SSSE3" > Revert "host/i386: assume presence of SSE2" > Revert "host/i386: assume presence of CMOV" > Revert "meson: assume x86-64-v2 baseline ISA" > > host/include/i386/host/cpuinfo.h | 3 +++ > meson.build | 10 +++------- > tcg/i386/tcg-target.c.inc | 15 ++++++++++++++- > tcg/i386/tcg-target.h | 5 +++-- > util/bufferiszero.c | 4 ++-- > util/cpuinfo-i386.c | 7 +++++-- > 6 files changed, 30 insertions(+), 14 deletions(-) > > -- > 2.32.0 > > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
