[PPL-devel] Re: Precision of doubles and stdio

On Sun, 2006-03-05 at 12:44 +0100, Roberto Bagnara wrote:

Tim Prince wrote: My

...

past reading of various relevant documents convinced me that digits beyond the 17th in formatting of doubles are not required by any standard to be consistent between implementations. They have no useful function, as 17 digits are sufficient to determine uniquely the corresponding binary value in IEEE 754 format.

Thank you Tim. We were unaware of this giant bug in the C standard. All the best,

There is no bug in the C Standard. The C standard makes it clear the accuracy of floating point operations is implementation defined ,and the implementor may even say the accuracy is undefined.

This is not a bug, it is the proper thing for a language standard.