Re: Euler Project Problems.
Gwenhwyfaer <[email protected]> Sat, 10 May 2008 21:35:03 +0100
| Newsgroups | gmane.comp.lang.forth.colorforth |
|---|---|
| Message-ID | <[email protected]> |
On 10/05/2008, Albert van der Horst <[email protected]> wrote: > On Fri, May 09, 2008 at 04:38:47PM -0600, Ray St. Marie wrote: > > I've spent a day trying to figure out how I will implement larger then > > 32 bit ( 27 really) numbers in colorforth for Project Euler Problem 3. > > > > Find the Greatest Prime Factor of 600851475143. > There is a division operator that spans 2 registers, effectively > doing the SM/REM action of ISO Forth in one instruction. > That is 64 by 32 bit division. > It is called IDIV Unfortunately, it only returns 32-bit (31-bit, if signed) results - which means that determining whether 3 is a factor of the above number will necessitate a true double-precision division (64/32 returning 64). Regards Gwenhwyfaer