Wait a minute, that's all wrong. Never mind. What is the type of 2^44 on a 64-bit system?
> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Henry Rich > Sent: Monday, May 28, 2007 12:23 PM > To: 'Programming forum' > Subject: RE: [Jprogramming] 64bit integers vs 32bit integers > > 2^44 is going to be floating-point, which will do its > thing regardless of how big your integers are. Try > 2x^44. > > I don't have a 64-bit system to test on. > > Henry Rich > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of david alis > > Sent: Monday, May 28, 2007 11:39 AM > > To: Programming forum > > Subject: [Jprogramming] 64bit integers vs 32bit integers > > > > Consider the expression > > foo=: 3 : 'assert. *./#:<:2^y' > > The smallest argument value which triggers the assertion > > failure is 44. > > This value is the same on both 32bit J (windows xp) and 64bit > > J (Ubuntu 7.04). > > (Aside: the expression #:<:2^N is the binary representation of _1 + > > 2^N, which, from the point of view of the language, must always be a > > sequence of 1's) > > > > I am puzzled by this result because in J-64 integers are indeed > > represented with 8bytes as can be demonstrated by: > > abcd =. 1000?1000 > > 7!:5<'abcd' returns > > 4096 -- with 32bit J > > 8192 -- with 64 bit J > > > > It is the difference in behaviour of the binary primitives between > > 32bit and 64bit that led me to believe that domain of precise > > arithmetic with integers would be greater in J64 than in J32. > > For example: > > 1 (17 b.)2^40 > > throws a domain error on 32bit J but returns 0 on 64bit J. > > > > Can someone explain? > > > > Regards > > David > > > ---------------------------------------------------------------------- > > For information about J forums see > > http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see > http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
