On Wed, Aug 26, 2020 at 11:16:48PM -0700, C K Kashyap wrote: > About why I am trying it - it's primarily just a learning exercise for me. > What I am trying is expanding the cell to 4 words instead of two and use > the extra words as the meta data and not require tagged pointers. This way
I see. > I could even build it with TCC that does not seem to align functions at 4 > byte boundary. OK, function pointer alignment is a different issue. You can however encode the pointer in different ways. Some versions of PicoLisp shift'ed and or'ed it. > Sorry if I am missing something, but wouldn't x-1 result in shifting the > pointer by 8 bytes instead of 4 (since size of cell is 8). Which is > probably why cdr is used instead of car? Yes. x-1 is minus 8 bytes, and the cdr adds 4 bytes. So the physical access goes to -4. ☺/ A!ex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
