Mathematical Library Functions                          ldexp(3M)



NAME
     ldexp, ldexpf, ldexpl - load exponent of  a  floating  point
     number

SYNOPSIS
     c99 [ flag... ] file... -lm [ library... ]
     #include 

     double ldexp(double x, int exp);


     float ldexpf(float x, int exp);


     long double ldexpl(long double x, int exp);


DESCRIPTION
     These functions computes the quantity x* 2^exp.

RETURN VALUES
     Upon successful completion, these functions return x  multi-
     plied by 2 raised to the power exp.


     If these functions  would  cause  overflow,  a  range  error
     occurs and ldexp(), ldexpf(), and ldexpl() return ]HUGEVAL,
     ]HUGEVALF, and ]HUGEVAL (according to  the  sign  of  x),
     respectively.


     If x is NaN, a NaN is returned.


     If x is ]0 or ]Inf, x is returned.


     If exp  is 0, x is returned.

ERORS
     These functions will fail if:

     Range Error    The result overflows.

                    If the integer expression (matherrhandling &
                    MATHEREXCEPT)  is  non-zero,  the  overflow
                    floating-point exception is raised.

                    The ldexp() function sets errno to ERANGE  if
                    the result overflows.





SunOS 5.11          Last change: 12 Jul 2006                    1






Mathematical Library Functions                          ldexp(3M)



USAGE
     An application wanting to check for exceptions  should  call
     feclearexcept(FEALEXCEPT) before calling these functions.
     On  return,  if  fetestexcept(FEINVALID    FEDIVBYZERO  
     FEOVERFLOW    FEUNDERFLOW)  is non-zero, an exception has
     been raised. An application should either examine the return
     value  or check the floating point exception flags to detect
     exceptions.


     An application can  also  set  errno  to  0  before  calling
     ldexp().  On  return,  if  errno  is  non-zero, an error has
     occurred. The ldexpf() and ldexpl()  functions  do  not  set
     errno.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Standard                    
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     frexp(3M), isnan(3M), modf(3M), attributes(5), standards(5)























SunOS 5.11          Last change: 12 Jul 2006                    2