http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58970
--- Comment #10 from Bernd Edlinger <bernd.edlinger at hotmail dot de> --- but this should'nt be neccessary then? if (bitoffset > *bitpos) { HOST_WIDE_INT adjust = bitoffset - *bitpos; - gcc_assert ((adjust % BITS_PER_UNIT) == 0); - gcc_assert (*offset != NULL_TREE); *bitpos += adjust; - *offset - = size_binop (MINUS_EXPR, *offset, size_int (adjust / BITS_PER_UNIT)); + if (*offset == NULL_TREE) + *offset = size_int (-adjust / BITS_PER_UNIT); + else + *offset + = size_binop (MINUS_EXPR, *offset, size_int (adjust / BITS_PER_UNIT)); *bitstart = 0; }