ldexp(3) [freebsd man page]

LDEXP(3)						   BSD Library Functions Manual 						  LDEXP(3)

NAME

     ldexp, ldexpf, ldexpl -- multiply floating-point number by integral power of 2

LIBRARY

     Math Library (libm, -lm)

SYNOPSIS

     #include <math.h>

     double
     ldexp(double x, int exp);

     float
     ldexpf(float x, int exp);

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

DESCRIPTION

     The ldexp(), ldexpf(), and ldexpl() functions multiply a floating-point number by an integral power of 2.

RETURN VALUES

     These functions return the value of x times 2 raised to the power exp.

SEE ALSO

     frexp(3), math(3), modf(3)

STANDARDS

     The ldexp(), ldexpf(), and ldexpl() functions conform to ISO/IEC 9899:1999 (``ISO C99'').

BSD
								   March 4, 2005							       BSD

ldexp(3M)						  Mathematical Library Functions						 ldexp(3M)

NAME

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

SYNOPSIS

       c99 [ flag... ] file... -lm [ library... ]
       #include <math.h>

       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 multiplied by 2 raised to the power exp.

       If  these  functions  would  cause  overflow,  a range error occurs and ldexp(), ldexpf(), and ldexpl() return +-HUGE_VAL, +-HUGE_VALF, and
       +-HUGE_VALL (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.

ERRORS

       These functions will fail if:

       Range Error    The result overflows.

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

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

USAGE

       An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before  calling	these  functions.  On  return,	if
       fetestexcept(FE_INVALID	|  FE_DIVBYZERO  |  FE_OVERFLOW  |  FE_UNDERFLOW) 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.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

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

SunOS 5.11							    12 Jul 2006 							 ldexp(3M)