Florent Defay <spira.inhabitant@xxxxxxxxx> writes: > /home/guest1/gcc/new_build/target/libgcc/../.././gcc/fp-bit.c:671: > undefined reference to `__ucmpsi2' __ucmpsi2 is a function which does an unsigned comparison of two 32-bit integers. You can get gcc to build that by compiling libgcc2.c with LIBGCC2_UNITS_PER_WORD defined as 2. If your processor has a carry flag, it will often be more efficient to provide an insn which does it, these days typically via cbranchsi4. Ian