http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48511
Summary: Implement Steele-White algorithm for numeric output
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: libfortran
AssignedTo: [email protected]
ReportedBy: [email protected]
Created attachment 23923
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23923
Demonstration of correct rounding a la Steele-White
In their paper "How to Print Floating-Point Numbers Accurately" [1], Steele &
White describe an algorithm which for a internal binary floating-point number
outputs the shortest external decimal representation of that number which
converts back to the original number.
This should be implemented in libfortran, possibly as a separate I/O rounding
mode.
It would eliminate the problem of getting "odd" numbers, like 0.177699999999...
when the value 0.1977 is much shorter and represents the same exact binary
value.
Basically, their algorithm does the same as the attached program demonstrates,
only more efficiently.
[1] http://grouper.ieee.org/groups/754/email/pdfq3pavhBfih.pdf
