NAME

       scalbn,  scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-point number by
       integral power of radix

LIBRARY

       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  of
       exp, 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   │
       ├───────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │scalbn(), scalbnf(), scalbnl(), scalbln(), scalblnf(),         │ Thread safety │ MT-Safe │
       │scalblnl()                                                     │               │         │
       └───────────────────────────────────────────────────────────────┴───────────────┴─────────┘

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 type double.

NOTES

       If FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent to ldexp(3).

BUGS

       Before glibc 2.20, these functions did not set errno for range errors.

SEE ALSO

       ldexp(3), scalb(3)