ISO/ IEC JTC1/SC22/WG14 N728

Document Number: WG14 N728r1/J11 97-091

C9X Revision Proposal

Title:  scalbn

Author: Fred J. Tydeman
Author Affiliation:  Tydeman Consulting
Postal Address: 3711 Del Robles Dr., Austin, Texas 78727-1814
E-mail Address: tydeman @
Telephone Number: +1 (512) 255-8696
Fax Number: +1 (512) 255-8696

Sponsor: J11
Date: 1997-06-25
Document History: Update to WG14 N680/J11 97-043
Proposal Category:
  X Correction
Area of Standard Affected:
  X Library
Prior Art: X/Open XPG
Target Audience: All users
Related Documents (if any): WG14/N657 item 6, WG14/N693.
Proposal Attached: X Yes
Abstract: Correct scalbn to be type generic on just the
floating-point type.

Changes based upon C9X Draft 10-pre1, 1997-05-05

Change scalbn to: The scalbn function


  #include <math.h>
  double scalbn( double x, int n );


The scalbn function computes x*FLT_RADIX**n efficiently, not normally
by computing FLT_RADIX**n explicitly.  A range error may occur.


The scalbn function returns x*FLT_RADIX**n.


7.7.6.x The scalbln function


  #include <math.h>
  double scalbln( double x, long int n );


The scalbln function is equivalent to the scalbn function, except
that the integral argument is long int.

Add 'scalbln' to the list of type-generic macros in 7.x.1 Type-generic
macros WG14/N693 J11/97-056 (line 45, page 69 pre-London mailing).