The gcc ebuild specifically drops all CFLAGS (line 133 of the ebuild) and pulls out the arch from the CFLAGS prior to doing so (line 124 of the ebuild).
I also get "illegal instruction" on anything gcc related if I use the ebuild of the pentium, even as simple as gcc -v blows up
So as I understand things - the current ebuilds for GCC under Funtoo are dropping all CFLAGS prior to compiling.
My issue is that I'm trying to build GCC on a Haswell E3-1231V3 for a Haswell G3250 Pentium which is a very cut down version of a Haswell. I have an LXC container on the E3 that I use to build packages for the G3250.
My CFLAGS for the pentium are
"-march=haswell -mno-aes -mno-avx -mno-avx2 -mno-bmi -mno-bmi2 -mno-f16c -mno-fma -mno-xsave -mno-xsaveopt -mabm -O2 -pipe"
I need those on the E3 system because obviously I can't compile AVX instructions into GCC and have it work on the pentium as it does not have AVX.
I appreciate the concept of not going crazy with CFLAGS on things like GCC - but in my case I'm totally stuck without the ability to get those -mno-* flags into my build.
I'm trying to simply use the Gentoo ebuild for GCC 7.3.0 to move forward right now - but I'm hoping that there is maybe an option that I've not noticed to get this working on the Funtoo ebuild
Thanks
John