exp#
Synopsis#
#include <math.h>
double exp(double x);
float expf(float x);
long double expl(long double x);
Status#
Partially implemented
Conformance#
IEEE Std 1003.1-2017
Description#
These functions shall compute the base e
exponential of x.
An application wishing to check for error situations should set errno
to zero and call
feclearexcept(FE_ALL_EXCEPT)
before calling these functions. On return, if errno
is non-zero or
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW)
is non-zero, an error has occurred.
Return value#
Upon successful completion, these functions shall return the exponential value of x.
If the correct value would cause overflow, a range error shall occur and
exp()
,expf()
, andexpl()
shall return the value of the macroHUGE_VAL
,HUGE_VALF
, andHUGE_VALL
, respectively.If the correct value would cause underflow, and is not representable, a range error may occur, and
exp()
,expf()
, andexpl()
shall return0.0
, or (if the IEC 60559 Floating-Point option is not supported) an implementation-defined value no greater in magnitude thanDBL_MIN
,FLT_MIN
, andLDBL_MIN
, respectively.If x is
NaN
, aNaN
shall be returned.If x is
±0
,1
shall be returned.If x is
-Inf
,+0
shall be returned.If x is
+Inf
, x shall be returned.If the correct value would cause underflow, and is representable, a range error may occur, and the correct value shall be returned.
Errors#
These functions shall fail if:
Range Error - The result overflows.
If the integer expression (math_errhandling & MATH_ERRNO)
is non-zero, then errno
shall be set to ERANGE
. If
the integer expression (math_errhandling & MATH_ERREXCEPT)
is non-zero, then the overflow floating-point exception
shall be raised.
These functions may fail if:
Range Error - The result underflows.
If the integer expression (math_errhandling & MATH_ERRNO)
is non-zero, then errno
shall be set to ERANGE
. If
the integer expression (math_errhandling & MATH_ERREXCEPT)
is non-zero, then the underflow floating-point exception
shall be raised.
Tests#
Untested
Known bugs#
None