Hi Joe, Thanks for the bug report. I've pushed fixes for both issues.
However there are still cases where 1 /f and >float give different results, eg ( scratchpad ) 60179602826890858042495329276589127743 [ 1 /f .h ] [ >float .h ] bi 1.6a315bfb1e4bfp125 1.6a315bfb1e4cp125 Which result is more accurate? ( scratchpad ) 60179602826890858042495329276589127743 [ dup 1 /f >integer - . ] [ dup >float >integer - . ] bi 4414195228865875032127 -5030537736873415395265 Perhaps we could get rid of the bignum>float primitive and redefine it as 1 bignum/f ? Slava On Fri, Nov 12, 2010 at 6:59 AM, Joe Groff <[email protected]> wrote: > A couple quick bugs in bignum-to-float division I found: > > - bignum/f rounds toward zero, when it should respect the floating point > rounding mode, or at least round to nearest. An easy test case is to divide a > bignum with more than 53 significant bits by 1: > > ( scratchpad ) HEX: 7f,ffff,ffff,ffff >bignum [ >float .h ] [ 1 /f .h ] bi > 1.0p55 > 1.fffffffffffffp54 > ( scratchpad ) HEX: -7f,ffff,ffff,ffff >bignum [ >float .h ] [ 1 /f .h ] bi > -1.0p55 > -1.fffffffffffffp54 > > For both of the above inputs, the first line is from >float, which correctly > rounds to the nearest floating-point number, and the second is from 1 /f, > which rounds toward zero. > > - Dividing bignum zero by zero gives 0.0, when it should give NAN: > > ( scratchpad ) 0 0 /f . > NAN: 8000000000000 > ( scratchpad ) 0 >bignum 0 /f . > 0.0 > > -Joe > ------------------------------------------------------------------------------ > Centralized Desktop Delivery: Dell and VMware Reference Architecture > Simplifying enterprise desktop deployment and management using > Dell EqualLogic storage and VMware View: A highly scalable, end-to-end > client virtualization framework. Read more! > http://p.sf.net/sfu/dell-eql-dev2dev > _______________________________________________ > Factor-talk mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/factor-talk > ------------------------------------------------------------------------------ Centralized Desktop Delivery: Dell and VMware Reference Architecture Simplifying enterprise desktop deployment and management using Dell EqualLogic storage and VMware View: A highly scalable, end-to-end client virtualization framework. Read more! http://p.sf.net/sfu/dell-eql-dev2dev _______________________________________________ Factor-talk mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/factor-talk
