Hi There, We are trying to compile gcc 8.3.0 in our new build system which have AVX512 feature. The program itself compiled without any problem. However, when I tried to run it on our old nodes (avx2), it get "mpi-pingpong.c: In function ‘main’: mpi-pingpong.c:20:4: internal compiler error: Illegal instruction double max_rate = 0.0, min_latency = 10e6; ^~~~~~ 0xa782ef crash_signal ../../gcc/toplev.c:325 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions." It works fine on our new avx512 nodes. We tried set BOOT_CFLAGS, disable-bootstrap and set up CFLAGS, but none of them works. Does anyone have experience on these, thanks? Regards, Jin Zhang