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SCALBLN(3P)                POSIX Programmer's Manual               SCALBLN(3P)
PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl -- compute  expo-
       nent using FLT_RADIX
SYNOPSIS
       #include <math.h>
       double scalbln(double x, long n);
       float scalblnf(float x, long n);
       long double scalblnl(long double x, long n);
       double scalbn(double x, int n);
       float scalbnf(float x, int n);
       long double scalbnl(long double x, int n);
DESCRIPTION
       The  functionality described on this reference page is aligned with the
       ISO C standard. Any conflict between the  requirements  described  here
       and  the  ISO C  standard is unintentional. This volume of POSIX.1-2008
       defers to the ISO C standard.
       These functions shall compute x * FLT_RADIXn efficiently, not  normally
       by computing FLT_RADIXn explicitly.
       An  application  wishing to check for error situations should set errno
       to zero and  call  feclearexcept(FE_ALL_EXCEPT)  before  calling  these
       functions. On return, if errno is non-zero or fetestexcept(FE_INVALID |
       FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero,  an  error  has
       occurred.
RETURN VALUE
       Upon    successful    completion,    these   functions   shall   return
       x * FLT_RADIXn.
       If the result would cause overflow, a range error shall occur and these
       functions   shall   return  +-HUGE_VAL,  +-HUGE_VALF,  and  +-HUGE_VALL
       (according to the sign of x) as appropriate for the return type of  the
       function.
       If the correct value would cause underflow, and is not representable, a
       range error may occur, and scalbln(), scalblnf(), scalblnl(), scalbn(),
       scalbnf(),  and  scalbnl() shall return 0.0, or (if IEC 60559 Floating-
       Point is not supported) an implementation-defined value no  greater  in
       magnitude  than  DBL_MIN,  FLT_MIN,  LDBL_MIN,  DBL_MIN,  FLT_MIN,  and
       LDBL_MIN, respectively.
       If x is NaN, a NaN shall be returned.
       If x is +-0 or +-Inf, x shall be returned.
       If n is 0, x shall be returned.
       If the correct value would cause underflow,  and  is  representable,  a
       range error may occur and the correct value shall be returned.
ERRORS
       These functions shall fail if:
       Range Error The result overflows.
                   If  the  integer expression (math_errhandling & MATH_ERRNO)
                   is non-zero, then errno shall be set to [ERANGE].   If  the
                   integer  expression  (math_errhandling & MATH_ERREXCEPT) is
                   non-zero, then the overflow floating-point exception  shall
                   be raised.
       These functions may fail if:
       Range Error The result underflows.
                   If  the  integer expression (math_errhandling & MATH_ERRNO)
                   is non-zero, then errno shall be set to [ERANGE].   If  the
                   integer  expression  (math_errhandling & MATH_ERREXCEPT) is
                   non-zero, then the underflow floating-point exception shall
                   be raised.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       On   error,   the   expressions  (math_errhandling  &  MATH_ERRNO)  and
       (math_errhandling & MATH_ERREXCEPT) are independent of each other,  but
       at least one of them must be non-zero.
RATIONALE
       These  functions are named so as to avoid conflicting with the histori-
       cal definition of the scalb() function from the Single UNIX  Specifica-
       tion. The difference is that the scalb() function has a second argument
       of double instead of int.  The scalb() function  is  not  part  of  the
       ISO C  standard. The three functions whose second type is long are pro-
       vided because the factor required to scale from the  smallest  positive
       floating-point  value  to  the  largest finite one, on many implementa-
       tions, is too large to represent in the minimum-width int format.
FUTURE DIRECTIONS
       None.
SEE ALSO
       feclearexcept(), fetestexcept()
       The Base Definitions volume of POSIX.1-2008, Section 4.19, Treatment of
       Error Conditions for Mathematical Functions, <math.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal  and  Electronics  Engineers,  Inc  and  The  Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  In  the
       event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard
       is  the  referee document. The original Standard can be obtained online
       at http://www.unix.org/online.html .
       Any typographical or formatting errors that appear  in  this  page  are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors,  see  https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                          SCALBLN(3P)