https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87370
--- Comment #12 from trashyankes at wp dot pl --- (In reply to H.J. Lu from comment #11) > (In reply to trashyankes from comment #10) > > Which GCC are you using? GCC 8.2 generates: GCC Explorer :D g++ (GCC-Explorer-Build) 9.0.0 20181211 (experimental) https://gcc.godbolt.org/z/7AQXiq Code is copy paste of test case. Compiler is x86-64 Important are flags: `-O3 -march=skylake-avx512` Without it compile this code fine.