floatingpoint(3M) (BSD Compatibility Package) floatingpoint(3M)
NAME
floatingpoint - IEEE floating point definitions
SYNOPSIS
/usr/ucb/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 Standard
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. 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 harare 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, if any, and
otherwise to dump core using abort.
SIGFPEIGNORE A macro indicating an alternate SIGFPE exception
handling, namely to ignore and continue execution.
Page 1 Reliant UNIX 5.44 Printed 11/98
floatingpoint(3M) (BSD Compatibility Package) floatingpoint(3M)
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 excep-
tions.
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 trap-
ping modes correspond to hardware modes, elements
of this array should only be modified with a func-
tion like ieeehandler that performs the appropri-
ate 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.
FILES
/usr/include/sys/ieeefp.h
/usr/include/fp.h
/usr/ucblib/libucb.a
Page 2 Reliant UNIX 5.44 Printed 11/98
floatingpoint(3M) (BSD Compatibility Package) floatingpoint(3M)
SEE ALSO
sigfpe(3), abort(3C), strtod(3C), ieeehandler(3M).
Page 3 Reliant UNIX 5.44 Printed 11/98