Name
scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-point number by integral power of radixLibrary
Math library ( libm ", " -lm )Synopsis
#include <math.h> double scalbln(double " x ", long exp );
float scalblnf(float " x ", long exp );
long double scalblnl(long double " x ", long exp );
double scalbn(double " x ", int exp );
float scalbnf(float " x ", int exp );
long double scalbnl(long double " x ", int exp );
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
scalbln() scalblnf() scalblnl()
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
scalbn() scalbnf() scalbnl()
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
Description
These functions multiply their first argument x by FLT_RADIX (probably 2) to the power ofexp, that is: x * FLT_RADIX ** exp
The definition of FLT_RADIX can be obtained by including <float.h>.
Return Value
On success, these functions return x * FLT_RADIX **exp. If x is a NaN, a NaN is returned.
If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned.
If x is +0 (-0), +0 (-0) 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.
If the result underflows, a range error occurs, and the functions return zero, 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 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.
Attributes
For an explanation of the terms used in this section, see attributes(7).| Interface | Attribute | Value |
| T} | Thread safety | MT-Safe |
Standards
C11, POSIX.1-2008.History
glibc 2.1. C99, POSIX.1-2001.History
These functions differ from the obsolete functions described in scalb(3) in the type of their second argument. The functions described on this page have a second argument of an integral type, while those in scalb(3) have a second argument of typedouble.