https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112331
--- Comment #4 from JuzheZhong <juzhe.zhong at rivai dot ai> --- I see. It does vectorize it with -fno-vect-cost-model -fno-loop-interchange: https://gcc.godbolt.org/z/8EEWcPro3 Codegen same as LLVM. I am gonna revisit it in GCC-15 (GCC-14 stage 1 is closing soon). Thanks a lot!