[Bug target/81616] Update -mtune=generic for the current Intel and AMD processors

[andrewm.roberts at sky dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81616

--- Comment #24 from Andrew Roberts <andrewm.roberts at sky dot com> ---
For the mt19937ar test:

/usr/local/gcc/bin/gcc -march=znver1 -mtune=znver1 -O3 mt19937ar.c -o mt19937ar
  mt19937ar took 462062 clocks

/usr/local/gcc/bin/gcc -march=znver1 -mtune=znver1 -mprefer-vector-width=none
-O3 mt19937ar.c -o mt19937ar
  mt19937ar took 412449 clocks

/usr/local/gcc/bin/gcc -march=znver1 -mtune=znver1 -mprefer-vector-width=none
-mno-fma -O3 mt19937ar.c -o mt19937ar
  mt19937ar took 419284 clocks

/usr/local/gcc/bin/gcc -march=haswell -mtune=haswell -mprefer-vector-width=none
-mno-fma -O3 mt19937ar.c -o mt19937ar
  mt19937ar took 436768 clocks

/usr/local/gcc/bin/gcc -march=corei7-avx -mtune=skylake -O3 mt19937ar.c -o
mt19937ar
  mt19937ar took 410302 clocks