[Bug rtl-optimization/64081] [5/6/7 Regression] r217827 prevents RTL loop unroll

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64081

--- Comment #30 from David Edelsohn <dje at gcc dot gnu.org> ---
.../src/src/configure --disable-werror --with-gmp=/opt/cfarm
--with-libiconv-prefix=/opt/cfarm --disable-libstdcxx-pch
--with-included-gettext

By the way, it's a lot faster if the src and build directories are in /scratch.
 It's a ramdisk for transient, temporary files, so don't leave things there
permanently.