floatingpoint(3)   UNIX System V(BSD Compatibility Package)    floatingpoint(3)


NAME
      floatingpoint - IEEE floating point definitions

SYNOPSIS
      cc [ flag. . . ] file . . . -lucb

      #include <sys/ieeefp.h>
      #include <fp.h>

DESCRIPTION
      This file defines constants, types, variables, and functions used to
      implement standard floating point according to ANSI/IEEE Std 754-1985.
      The variables and functions are implemented in libucb.a.  The included
      file <sys/ieeefp.h> defines certain types of interest to the kernel.

      IEEE Rounding Modes:

     fpdirectiontype
                       The type of the IEEE rounding direction mode.  Note: the
                       order of enumeration varies according to hardware.

     fpdirection     The IEEE rounding direction mode currently in force.
                       This is a global variable that is intended to reflect
                       the hardware state, so it should only be written
                       indirectly through a function that also sets the
                       hardware state.

     fpprecisiontype
                       The type of the IEEE rounding precision mode, which only
                       applies on systems that support extended precision.

     fpprecision     The IEEE rounding precision mode currently in force.
                       This is a global variable that is intended to reflect
                       the hardware state on systems with extended precision,
                       so it should only be written indirectly.

      SIGFPE Handling:

     sigfpecodetype The type of a SIGFPE code.

     sigfpehandlertype
                       The type of a user-definable SIGFPE exception handler
                       called to handle a particular SIGFPE code.

     SIGFPEDEFAULT   A macro indicating the default SIGFPE exception handling,
                       namely to perform the exception handling specified by
                       calls to ieeehandler(3M), if any, and otherwise to dump
                       core using abort(3).

     SIGFPEIGNORE    A macro indicating an alternate SIGFPE exception
                       handling, namely to ignore and continue execution.



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floatingpoint(3)   UNIX System V(BSD Compatibility Package)    floatingpoint(3)


     SIGFPEABORT     A macro indicating an alternate SIGFPE exception
                       handling, namely to abort with a core dump.

      IEEE Exception Handling:

     NIEEEEXCEPTION The number of distinct IEEE floating-point exceptions.

     fpexceptiontype
                       The type of the NIEEEEXCEPTION exceptions.  Each
                       exception is given a bit number.

     fpexceptionfieldtype
                       The type intended to hold at least NIEEEEXCEPTION bits
                       corresponding to the IEEE exceptions numbered by
                       fpexceptiontype.  Thus fpinexact corresponds to the
                       least significant bit and fpinvalid to the fifth least
                       significant bit.  Note: some operations may set more
                       than one exception.

     fpaccruedexceptions
                       The IEEE exceptions between the time this global
                       variable was last cleared, and the last time a function
                       was called to update the variable by obtaining the
                       hardware state.

     ieeehandlers    An array of user-specifiable signal handlers for use by
                       the standard SIGFPE handler for IEEE arithmetic-related
                       SIGFPE codes.  Since IEEE trapping modes correspond to
                       hardware modes, elements of this array should only be
                       modified with a function like ieeehandler(3M) that
                       performs the appropriate hardware mode update.  If no
                       sigfpehandler has been declared for a particular IEEE-
                       related SIGFPE code, then the related ieeehandlers will
                       be invoked.

      IEEE Formats and Classification:

     single;extended  Definitions of IEEE formats.

     fpclasstype    An enumeration of the various classes of IEEE values and
                       symbols.

      IEEE Base Conversion:

      The functions described under floatingtodecimal(3) and
      decimaltofloating(3) not only satisfy the IEEE Standard, but also the
      stricter requirements of correct rounding for all arguments.

     DECIMALSTRINGLENGTH
                       The length of a decimalstring.




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floatingpoint(3)   UNIX System V(BSD Compatibility Package)    floatingpoint(3)


     decimalstring   The digit buffer in a decimalrecord.

     decimalrecord   The canonical form for representing an unpacked decimal
                       floating-point number.

     decimalform     The type used to specify fixed or floating binary to
                       decimal conversion.

     decimalmode     A struct that contains specifications for conversion
                       between binary and decimal.

     decimalstringform
                       An enumeration of possible valid character strings
                       representing floating-point numbers, infinities, or
                       NaNs.

FILES
      /usr/include/sys/ieeefp.h
      /usr/include/fp.h
      /usr/ucblib/libucb.a

SEE ALSO
      decimaltofloating(3), econvert(3), floatingtodecimal(3),
      ieeehandler(3M), sigfpe(3)

      abort(3), strtod(3) in the Programmer's Reference Manual




























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