scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-point number by integral power of radix
Math library (libm
, -lm
)
#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)):
These functions multiply their first argument x
by
FLT_RADIX (probably 2) to the power of exp
,
that is:
x * FLT_RADIX ** exp
The definition of FLT_RADIX can be obtained by
including <float.h>
.
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
.
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
An overflow floating-point exception (FE_OVERFLOW) is raised.
errno
is set to ERANGE. An underflow
floating-point exception (FE_UNDERFLOW) is raised.
C11, POSIX.1-2008.
Before glibc 2.20, these functions did not set errno
for
range errors.