Hi Dave, On Wed, Sep 08, 2010 at 11:14:30PM -0700, Dave Hylands wrote: > Replying to the list this time... finally an answer to *my* problem, thanks :-D > Another general rule, is that on 32-bit CPUs you can only do 32-bit > arithmetic, with 64-bit addition, subtraction, and multiplications. > 64-bit divides must be done using do_div or do_div64. > I've understood so far your explanations. But one thing I am missing: I claim that I do not do an 64-bit division, but an 32-bit division. Why? I have run make tags to create an architecture dependent tags file. When I go to s64 and jump to the definition I land in include/asm-generic/int-l64.h . There is the typedef: typedef signed long s64; On my system, the size of long int is the same as int (I've wrote a simple C program to get this information). I.e. there should be no difference between an 'signed int division' and an 'signed long division'. What am I missing? Another question: I've encountered several #ifdef __ASSEMBLY__ and __KERNEL__ in the header files. What do these two preprocessor definitions stand for? Thanks in advance for your help! Andreas -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
