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)
