LDEXP(3M) | Mathematical Library Functions | LDEXP(3M) |

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

c99 [flag... ]file...-lm[library... ] #include <math.h>doubleldexp(doublex,intexp);

floatldexpf(floatx,intexp);

long doubleldexpl(long doublex,intexp);

These functions computes the quantity x* 2^exp.

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.

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.

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**.

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE | ATTRIBUTE VALUE |

Interface Stability | Standard |

MT-Level | MT-Safe |

July 12, 2006 | SunOS 5.11 |