Thanks to #4715, GROMACS selects AVX512 for Zen 4, which sets ``` SIMD_AVX_512_CXX_FLAGS:INTERNAL= -xCORE-AVX512 -qopt-zmm-usage=high SIMD_AVX_512_C_FLAGS:INTERNAL= -xCORE-AVX512 -qopt-zmm-usage=high ``` This flag is not generating the code that runs on Zen 4. That is, after compiling and running tests, they fail with: > Please verify that both the operating system and the processor support Intel(R) X87, CMOV, MMX, SSE, SSE2, SSE3, SSSE3, SSE4_1, SSE4_2, MOVBE, POPCNT, AVX, F16C, FMA, BMI, LZCNT, AVX2, AVX512F, AVX512DQ, ADX, AVX512CD, AVX512BW and AVX512VL instructions. We should get something like: ``` -march=skylake-avx512 ``` instead (`-march=znver4` is supported only from version 2024). I see two ways to fix this: - introduce another branch under AVX-512F that selects different flags if AMD CPU was detected, or - switch to newer style compile flags for Intel and AMD CPUs since we don't support legacy Intel compiler anymore. CC @mark.j.abraham