m3core/src/float/Common/DragonT.i3

 Copyright (C) 1992, Digital Equipment Corporation                         
 All rights reserved.                                                      
 See the file COPYRIGHT for a full description.                            
                                                                           
 Last modified on Fri Jun 17 10:40:07 PDT 1994 by kalsow                   
      modified on Fri May  7 17:17:14 PDT 1993 by muller                   


INTERFACE DragonT;

IMPORT Ctypes;

TYPE
  CutoffMode = {normal, absolute, relative};
  Digit = [0 .. 9];

PROCEDURE F (e           : INTEGER;
             f1, f0      : INTEGER;
             p           : INTEGER;
             cutoffMode  : CutoffMode;
             cutoffPlace : INTEGER;
  VAR(*OUT*) digits      : ARRAY OF Digit;
  VAR(*OUT*) count       : CARDINAL;
  VAR(*OUT*) exp         : INTEGER);

 Implements the Dragon algorithm to print floating-point numbers.
   The 64 mantissa bits are ((f1 & 16_ffffffff) << 32) + (f0 & 16_ffffffff) 

<*EXTERNAL strtod*>
PROCEDURE strtod (nptr: Ctypes.char_star;
                  eptr: Ctypes.char_star_star): LONGREAL;

END DragonT.


   The Dragon algorithm is described in:



             "How to Print Floating-Point Numbers Accurately",
             Guy L. Steele Jr. and Jon L. White, 
             Proceedings of the ACM Sigplan'90 conference on Programming 
             Language Design and Implementation, 
             pp 112-126.