Reported by Coverity: if we fail to run the AVX2 version, once
execve() fails, we had already replaced argv[0] with the new
stack-allocated path string, and that's then passed back to
main(). Use a static variable instead.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Build-time selection of AVX2 flags and routines is not practical for
distributions, but limiting AVX2 usage to checksum routines with
specific run-time detection doesn't allow for easy performance gains
from auto-vectorisation of batched packet handling routines.
For x86_64, build non-AVX2 and AVX2 binaries, and implement a simple
wrapper replacing the current executable with the AVX2 build if it's
available, and if AVX2 is supported by the current CPU.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
