> Who is calling CONST_DOUBLE_LOW on this value? plus_constant calls CONST_DOUBLE_LOW on this value. simplify_binary_operation_1 calls plus_constant ( while trying to simplify PLUS on (const_double:SF 0 [0x0] 0.0 [0x0.0p+0]) & (const_int -2147483648 [0x80000000]) ), which in turn calls CONST_DOUBLE_LOW. Thanks, Pranav