I have 2 Intel Pentium processors that I'm unable to build GCC for.
They both have the same type of issue so I'll just pick one for this description
A Pentium G3250 is a Haswell chip but it lacks several features - most easily identified are AES and AVX/AVX2
So the CFLAGS for this chip areĀ
-march=haswell -mno-aes -mno-avx -mno-avx2 -mno-bmi -mno-bmi2 -mno-f16c -mno-fma -mno-xsave -mno-xsaveopt -mabm -O2 -pipe
Those are derived from the older instructions on the Gentoo Safe CFlags page and they are basically that I compiled an empty file with march=native and then compiled with march=haswell and compared what GCC spits out for the flags and that is what is the difference between them.
So my problem is that when the GCC ebuild comes along and drops all CFLAGS - I end up building a GCC which has AES and AVX/AVX2 instructions in it and I can't even run "gcc -v" on the result because it returns an illegal instruction error.
I understand the desire to limit the flags because it opens the door to weird issues - but could that policy be modified to allow theĀ -mno* flags through so I can get these flags through?