On Dec 29, 2009, at 9:14 PM, Peter Jeremy wrote: > On 2009-Dec-29 23:57:13 +0000, "Dr. David Kirkby" <david.kir...@onetel.net > > wrote: >> Peter Jeremy wrote: >> Yes it does. And I can understand why, since for 99% of programs, >> there is no >> advantage to 64-bit, but some disadvantages (larger pointers, let >> fit in cache >> etc). > > OTOH, programs doing multi-precision integer math should benefit from > 64-bit arithmetic - and I would expect that at least some parts of > Sage would benefit from this.
Yep, 64-bit based multi-precision can be up to 4 times as fast. And unlike most of the world, users of Sage use their computers to actually compute. > The crucial advantage of 64-bit is (effectively) unlimited address > space - if you need to manipulate more than ~2GB data then 64-bit > is the only way to go. For sure, and we do this all the time :). > x86 vs x86_64 isn't as clearcut because the x86 architecture is so > badly designed - the relatively small number and lack of orthogonality > of registers and lack of a 16-bit relative addressing mode makes the > code relatively large for a 32-bit CISC architecture (it's close in > size to the RISC SPARC). > against it. I was under the impression that x86-64 actually tried to resolve some of the x86 cruft (e.g. adding more registers and increasing their flexibility), though of course it's still rather constrained due to backwards compatibility requirements. - Robert -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
