_ldexp -- Fast Implementation of ldexp

SYNOPSIS

 #include <lcmath.h>

 double _ldexp (double y, int n);
 

DESCRIPTION

_ldexp calculates y(2**n). It is almost identical to ldexp but it is faster because no error checking is performed.

RETURN VALUE

_ldexp returns the value of type double that results from the calculation.

DIAGNOSTICS

_ldexp generates the SIGFPOFL or SIGFPUFL signal if an error occurs.

PORTABILITY

_ldexp is not portable.

IMPLEMENTATION

_ldexp is implemented as a built-in function unless it is undefined by an #undef statement.

The difference between ldexp and _ldexp is that _ldexp does not check for erroneous arguments, so an ABEND OCC or OCD occurs if the arguments are invalid. Because _ldexp avoids error checking, it is significantly faster than ldexp.

RELATED FUNCTIONS

ldexp

SEE ALSO

Mathematical Functions

Copyright (c) 1998 SAS Institute Inc. Cary, NC, USA. All rights reserved.