I just tried to abuse autoconf's --program-suffix feature (../configure --program-suffix="-4.0") to have gcc 3.4.x and 4.0 in the same directory without conflicts. Looks like the configure option is completely ignored -- the resulting binaries are named as usual.
-- Summary: Makefiles don't handle configure --program-suffix Product: gcc Version: 4.0.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: other AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: bero at arklinux dot org CC: gcc-bugs at gcc dot gnu dot org GCC host triplet: i586-ark-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19563