On Fri, Jul 22, 2022 at 02:23:13AM +0000, Zhao, Zhou wrote: > 1 we need gcc machined options to tirgger gcc enable SIMD > instructions(https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html). > Or it will trigger a compile error. This is the reason why we > change the config file.
Take a look at util/bufferiszero.c - that uses '#pragma GCC target' to selectively change the compule target of individual functions. This is what is njeeded here, because most distros are going to compile QEMU with a very old x86_64 baseline, never turn on avx512 for the whole QEMU build. It needs to be very selective to make it usable for typical deployments. 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 :|
