[Bug regression/71231] [7 Regression]: 300% runtime increase for rnflow

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71231

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This code has the following warning:
!CRAY - The following multiply must be done with 64 bits (not 46 bits)
!       The algoritm depends on the overflow characteristics of
!       a 32 or 64 bit multiply.


So the code is implicitly saying it needs to be done using overflow as wrapping
for signed integer but in Fortran, overflow is undefined.

This is the code from genuni.