NAME

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

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);

       Link with -lm.

   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.

VERSIONS

       These functions first appeared in glibc in version 2.1.

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()                                                     │               │         │
       └───────────────────────────────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO

       C99, POSIX.1-2001, POSIX.1-2008.

NOTES

       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.

       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)

COLOPHON

       This  page  is  part of release 5.13 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of  this  page,  can  be
       found at https://www.kernel.org/doc/man-pages/.

                                            2021-03-22                                 SCALBLN(3)