[Bug fortran/105558] simple 8-bit integer calculation fails with -O3 / march=core-avx2 on some gfortran 8/9/10 versions

[federico.perini at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105558

--- Comment #2 from federico <federico.perini at gmail dot com> ---
Ok so we have: 

gfortran | [...] -fno-tree-vectorize | [...] -fno-vect-cost-model
    10.3 |                        OK |                     ERROR
     9.3 |                        OK |                     ERROR 
     8.3 |                        OK |                     ERROR