On Tue, Aug 25, 2009 at 12:49 PM, Daniel Ehrenberg<micro...@gmail.com> wrote: > On register-based architectures (like the PIC18, right?), doing > everything with a stack is inherently inefficient because of peeks and > replaces on the top of the stack.
Dan didn't explain this, but a 'peek' is a load of an indexed stack location, and a 'replace' is a store of an indexed stack location; if you think of a stack as an array where stack[0] is the top of the stack, then you just have peek(x,n): x := stack[n] replace(x,n): stack[n] := x Factor's low-level stack optimization pass breaks stack manipulation down into abstract instructions representing peeks, replaces, and stack height changes. It attempts to insert as few peeks and replaces as possible, using a heuristic. When the final code generator encounters them, it generates moves between memory and registers. Slava ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Factor-talk mailing list Factor-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/factor-talk
