EXP2(3M) | Mathematical Library Functions | EXP2(3M) |

exp2, exp2f, exp2l - exponential base 2 functions

c99 [flag... ]file...-lm[library... ] #include <math.h>doubleexp2(doublex);

floatexp2f(floatx);

long doubleexp2l(long doublex);

These functions compute the base-2 exponential of *x*.

Upon successful completion, these functions return 2^*x*.

If the correct value would cause overflow, a range error occurs
and **exp2()**, **exp2f()**, and **exp2l()** return the value of
the macro **HUGE_VAL**, **HUGE_VALF**, and **HUGE_VALL**,
respectively.

If *x* is NaN, a NaN is returned.

If *x* is ±0, 1 is returned.

If *x* is −Inf, +0 is returned.

If *x* is +Inf, *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
will be raised.

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.

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

ATTRIBUTE TYPE | ATTRIBUTE VALUE |

Interface Stability | Standard |

MT-Level | MT-Safe |

math.h(3HEAD), exp(3M), feclearexcept(3M), fetestexcept(3M), isnan(3M), log(3M), attributes(7), standards(7)

July 12, 2006 | SunOS 5.11 |