Test testsuite/gcc.dg/builtin-return-1.c will fail for avr target. Default implementation of builtin-return-1 is untyped return of a single register. Which is R25 and only 1 byte. This is not int as test expects. So high byte may and does get overwritten before outer return.
The test may be invalid, but this is also reminder that AVR target does not have a complete definition for untyped return. The default is pretty useless. Test with be marked XFAIL. -- Summary: Default untyped return for AVR is byte register. Product: gcc Version: 4.4.0 Status: UNCONFIRMED Severity: minor Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: hutchinsonandy at gcc dot gnu dot org GCC build triplet: i686-pc-linux-gnu GCC host triplet: i686-pc-linux-gnu GCC target triplet: avr-unknown-nne http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36571