exp2(3M) Mathematical Library Functions exp2(3M)NAME
exp2, exp2f, exp2l - exponential base 2 functions
SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include <math.h>
double exp2(double x);
float exp2f(float x);
long double exp2l(long double x);
DESCRIPTION
These functions compute the base-2 exponential of x.
RETURN VALUES
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.
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 will be raised.
USAGE
An application wanting to check for exceptions should call feclearex‐
cept(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.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOexp(3M), feclearexcept(3M), fetestexcept(3M), isnan(3M), log(3M),
math.h(3HEAD), attributes(5), standards(5)SunOS 5.10 12 Jul 2006 exp2(3M)