This adds an sse42 cpu check on startup for both linux and windows,
mac has been excluded, since there are no intel based macs that do
not support SSE42.
The way this works is, we count on the OS to initialize the shared
libraries in the order they are linked (which currently holds true)
before calling the initialization code in the main executable. This
allows us to check the CPU before running any of the code in the main
executable that might not be supported by the current isa.
Changing those build flags is for a future PR, but for now and for
future reference: blender_cpu_check must be build without optimized CPU
flags so it'll be able to run on older CPUs.
some code has been duplicated from blenlib, there's really no way around
that since we cannot link blenlib as it may be build with optimized cpu
flags.
Windows currently gives a popup to inform the user, while linux reports
to the console, there may be better ways to communicate with linux users
with perhaps some generic GUI popup, but I'm unaware of these and will
leave this for the linux platform maintainer to polish.
Part of #116592
Pull Request: https://projects.blender.org/blender/blender/pulls/118054
0326b29899