# ldexpf(3m) [sunos man page]

ldexp(3M) Mathematical Library Functions ldexp(3M)NAME

ldexp, ldexpf, ldexpl - load exponent of a floating point numberSYNOPSIS

cc [ flag... ] file...[ library... ] #include <math.h> double ldexp(double x, int exp); float ldexpf(float x, int exp); long double ldexpl(long double x, int exp);-lmDESCRIPTION

These functions computes the quantity x* 2**exp.RETURN VALUES

Upon successful completion, these functions return x multiplied by 2 raised to the power exp. If these functions would cause overflow, a range error occurs and ldexp(), ldexpf(), and ldexpl() return +-HUGE_VAL, +-HUGE_VALF, and +-HUGE_VALL (according to the sign of x), respectively. If x is NaN, a NaN is returned. If x is +-0 or +-Inf, x is returned. If exp is 0, 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 is raised. The ldexp() function sets errno to ERANGE if the result overflows.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. An application can also set errno to 0 before calling ldexp(). On return, if errno is non-zero, an error has occurred. The ldexpf() and ldexpl() functions do not set errno.ATTRIBUTES

See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+SEE ALSO

frexp(3M), isnan(3M), modf(3M), attributes(5), standards(5)SunOS 5.1016 Aug 2004 ldexp(3M)

## Check Out this Related Man Page

LDEXP(3) Linux Programmer's Manual LDEXP(3)NAME

ldexp, ldexpf, ldexpl - multiply floating-point number by integral power of 2SYNOPSIS

#include <math.h> double ldexp(double x, int exp); float ldexpf(float x, int exp); long double ldexpl(long double x, int exp); Link withFeature Test Macro Requirements for glibc (see feature_test_macros(7)): ldexpf(), ldexpl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc-lm.-std=c99DESCRIPTION

The ldexp() function returns the result of multiplying the floating-point number x by 2 raised to the power exp.RETURN VALUE

On success, these functions return x * (2^exp). If exp is zero, then x is returned. If x is a NaN, a NaN is returned. If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned. If the result underflows, an range error occurs, and zero is returned. If the result overflows, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with a sign the same as x.ERRORS

See 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 TO

C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.SEE ALSO

frexp(3), modf(3), scalbln(3)COLOPHON

This page is part of release 3.25 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/. 2008-08-05 LDEXP(3)