Mark Dickinson wrote:
On Tue, Dec 9, 2008 at 5:15 PM, Steve Holden <steve@holdenweb.com> wrote:
precision than the usual 56-bit mantissa. Do modern 64-bit systems implement anything wider than the normal double?
I may have misinterpreted your question. Are you asking simply about what the hardware provides, or about what the C compiler and library support? Or something else entirely?
It looks like IEEE-conforming 128-bit floats would have a 113-bit mantissa (including the implicit leading '1' bit).
I was actually asking about Python implementations, and read your original answer as meaning "no, there aren't any". I had assumed, correctly or otherwise, that the C library would have to offer well-integrated support to enable its use in Python. In fact I had assumed it would need to be pretty much a drop-in repleacement, but it sounds as though there are some hard-coded assumptions about float size that would not allow that. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/