search

OpenMandrivaAssociation / distribution

OpenMandriva Lx is an exciting free Desktop Operating System that aims to cater to and interest first time and advanced users alike. It has the breadth and depth of an advanced system but is designed to be simple and straightforward in use.
https://openmandriva.org
8 stars 2 forks source link

glibc-hwcaps support? #2738

Open tpgxyz opened 3 years ago

tpgxyz commented 3 years ago

x86-64-v2 is supported by Intel Nehalem released in 2008. More infor here https://en.wikipedia.org/wiki/X86-64#Microarchitecture_levels GCC and LLVM already support it.

abucodonosor commented 3 years ago

Nope, not working that way.

If you want to go with that you need a glibc with glibc-hwcaps support for whatever you want supporting. That means also you have to compile multiple sets of the same SW and find a way to restrict usage on other CPUs.

EG: a CPU which lacks AVX, SSE3/4 support is broken if you force those compiler flags by default.

If you just enable v2 by default, which enables sse3/sse4 etc you break the crap out of any older still supported 64bit CPUs.

berolinux commented 3 years ago

-march=x86_64-v2 does break CPUs that don't have the needed features -- and I think quite a few people are still using those (remember how things started to break for people when mesa was accidentally compiled with SSE3?)

But of course there's things we can do, e.g. drop znver1 for x86_64-v3 or so.