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
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.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+----------------------------+-----------------------------+
|Interface Stability | Standard |
+----------------------------+-----------------------------+
|MT-Level | MT-Safe |
+----------------------------+-----------------------------+
SEE ALSO
math.h(3HEAD),
exp(3M),
feclearexcept(3M),
fetestexcept(3M),
isnan(3M),
log(3M),
attributes(7),
standards(7)SunOS 5.11 July 12, 2006 EXP2(3M)
