Re: [gambit-list] Fix garbage collector bug on 64 bit systems

On 2010-12-06, at 9:19 AM, Bradley Lucier wrote:

Marc:

In lib/mem.c you changed

   @@ -345,7 +345,7 @@ ___HIDDEN long words_prev_msections;

    /* words usable in msections */
    #define WORDS_MOVABLE_USABLE \
   -(2*the_msections->nb_sections*((___MSECTION_SIZE>>1)-___MSECTION_FUDGE+1))
   +(2*the_msections->nb_sections*(long)((___MSECTION_SIZE>>1)-___MSECTION_FUDGE+1))

Perhaps your intention was to ensure that some part of the computation will be done in 64-bit arithmetic, but on 64-bit Windows I believe (but am not sure) that (long) is 32-bits, and that you need (long long) to get 64-bits.

One should probably use a 64-bit type defined in gambit.h.

I'll have to think about this one. The intent is to use the natural word size, but not bigger. If I use ___I64 then a 64 bit computation will be done on 32 bit machines, which is a waste. Perhaps I should just use ___WORD. Hmmmm...

Marc