|LDEXP(3)||Linux Programmer's Manual||LDEXP(3)|
NAMEldexp, ldexpf, ldexpl - multiply floating-point number by integral power of 2
double ldexp(double x , int exp );
float ldexpf(float x , int exp );
long double ldexpl(long double x , int exp );
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;or cc -std=c99
DESCRIPTIONThe ldexp() function returns the result of multiplying the floating-point number x by 2 raised to the power exp.
RETURN VALUEOn success, these functions return x * (2^exp).
ERRORSSee math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
- Range error, overflow
- errno is set to ERANGE. An overflow floating-point exception ( FE_OVERFLOW) is raised.
- Range error, underflow
- errno is set to ERANGE. An underflow floating-point exception ( FE_UNDERFLOW) is raised.
CONFORMING TOC99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.
SEE ALSOfrexp(3), modf(3), scalbln(3)
COLOPHONThis page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.