Update.

1998-07-10 18:14 -0400  Zack Weinberg  <zack@rabi.phys.columbia.edu>

	* manual/Makefile: Overhauled.  Generate libc.texinfo from the
	chapter files.  Exorcise the chapters, chapters-incl mess.
	Support inserting doc chapters from add-on modules.
	(chapters): New variable.
	(add-chapters): New variable.
	(appendices): New variable.
	(libc.texinfo): New target.
	(clean): Fix bugs.
	(realclean): Fix bugs.

	* manual/texis.awk: New file.
	* manual/libc-texinfo.sh: New file.
	* manual/libc-texinfo.in: New file.

	* manual/conf.texi (top @node): Remove next pointer.
	* manual/lang.texi (top @node): Remove prev pointer.

	* manual/job.texi (top @node): Add explicit pointers.
	* manual/message.texi (top @node): Add explicit pointers.
	* manual/nss.texi (top @node): Add explicit pointers.
	* manual/process.texi (top @node): Add explicit pointers.
	* manual/startup.texi (top @node): Add explicit pointers.
	* manual/terminal.texi (top @node): Add explicit pointers.
	* manual/users.texi (top @node): Add explicit pointers.

	* manual/arith.texi: Add %MENU% tag.
	* manual/conf.texi: Add %MENU% tag.
	* manual/contrib.texi: Add %MENU% tag.
	* manual/ctype.texi: Add %MENU% tag.
	* manual/errno.texi: Add %MENU% tag.
	* manual/filesys.texi: Add %MENU% tag.
	* manual/header.texi: Add %MENU% tag.
	* manual/install.texi: Add %MENU% tag.
	* manual/intro.texi: Add %MENU% tag.
	* manual/io.texi: Add %MENU% tag.
	* manual/job.texi: Add %MENU% tag.
	* manual/lang.texi: Add %MENU% tag.
	* manual/llio.texi: Add %MENU% tag.
	* manual/locale.texi: Add %MENU% tag.
	* manual/maint.texi: Add %MENU% tag.
	* manual/math.texi: Add %MENU% tag.
	* manual/mbyte.texi: Add %MENU% tag.
	* manual/memory.texi: Add %MENU% tag.
	* manual/message.texi: Add %MENU% tag.
	* manual/nss.texi: Add %MENU% tag.
	* manual/pattern.texi: Add %MENU% tag.
	* manual/pipe.texi: Add %MENU% tag.
	* manual/process.texi: Add %MENU% tag.
	* manual/search.texi: Add %MENU% tag.
	* manual/setjmp.texi: Add %MENU% tag.
	* manual/signal.texi: Add %MENU% tag.
	* manual/socket.texi: Add %MENU% tag.
	* manual/startup.texi: Add %MENU% tag.
	* manual/stdio.texi: Add %MENU% tag.
	* manual/string.texi: Add %MENU% tag.
	* manual/sysinfo.texi: Add %MENU% tag.
	* manual/terminal.texi: Add %MENU% tag.
	* manual/time.texi: Add %MENU% tag.
	* manual/users.texi: Add %MENU% tag.

1998-07-13  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/unix/sysv/linux/i386/dl-procinfo.h (x86_cap_flags):
	Update.

1998-07-11  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* sysdeps/unix/sysv/linux/recvmsg.c (__libc_recvmsg): Use ANSI
	style declaration to avoid warning.
	* sysdeps/unix/sysv/linux/sendmsg.c (__libc_sendmsg): Likewise.

1998-07-04  Mark Kettenis  <kettenis@phys.uva.nl>

	* elf/rtld.c (process_dl_debug): Add missing continue.

1998-07-12  Mark Kettenis  <kettenis@phys.uva.nl>

	* elf/rtld.c (_dl_skip_args): Make global because the Hurd startup
	code needs it.

1998-07-10  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* Makeconfig ($(common-objpfx)sysd-dirs): Write out definition of
	sysd-dirs-done.
	* Makerules: Don't generate version maps too early.
	($(common-objpfx)sysd-versions): Force regeneration if the list of
	subdirs has changed.

1998-07-10  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* elf/dlfcn.h (DL_CALL_FCT): Use portable comma expression.

1998-07-11  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* iconv/gconv_db.c (gen_steps): Always set *handle and *nsteps.
	* iconv/gconv_dl.c (__gconv_find_shlib): Correct use of tfind
	return value.

1998-07-12  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* elf/dl-open.c (dl_open_worker): New function.
	(_dl_open): Call it to do the actual work while catching errors.
	* elf/dl-close.c (_dl_close): Only call termination function if
	the initialisation function was called.

1998-07-13  Ulrich Drepper  <drepper@cygnus.com>

	* libio/libioP.h (_IO_cleanup_registration_needed): Use __PMT.
	Reported by Felix von Leitner <leitner@amdiv.de>.

1998-07-13 10:28  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* elf/rtld.c (process_dl_debug): Add missing continue.

1998-06-23  Mark Kettenis  <kettenis@phys.uva.nl>

1 files changed, 454 insertions, 941 deletions

diff --git a/manual/math.texi b/manual/math.texi
index 1991bfbdb8..10b326287e 100644
--- a/manual/math.texi
+++ b/manual/math.texi
@@ -1,739 +1,129 @@
 @c We need some definitions here.
+@ifclear mult
 @ifhtml
-@set mult ·
+@set mult ·
+@set infty ∞
+@set pie π
 @end ifhtml
 @iftex
 @set mult @cdot
+@set infty @infty
 @end iftex
 @ifclear mult
-@set mult x
+@set mult *
+@set infty oo
+@set pie pi
 @end ifclear
 @macro mul
 @value{mult}
 @end macro
-@iftex
-@set infty @infty
-@end iftex
-@ifclear infty
-@set infty oo
-@end ifclear
 @macro infinity
 @value{infty}
 @end macro
+@ifnottex
+@macro pi
+@value{pie}
+@end macro
+@end ifnottex
+@end ifclear
 
 @node Mathematics, Arithmetic, Low-Level Terminal Interface, Top
+@c %MENU% Math functions, useful constants, random numbers
 @chapter Mathematics
 
 This chapter contains information about functions for performing
 mathematical computations, such as trigonometric functions.  Most of
 these functions have prototypes declared in the header file
-@file{math.h}.
+@file{math.h}.  The complex-valued functions are defined in
+@file{complex.h}.
 @pindex math.h
-
-For all functions which take a single floating-point argument and for
-several other functions as well there are three different functions
-available for the type @code{double}, @code{float}, and @code{long
-double}.  The @code{double} versions of the functions are mostly defined
-even in the @w{ISO C 89} standard.  The @code{float} and @code{long
-double} variants are introduced in the numeric extensions for the C
-language which are part of the @w{ISO C 9X} standard.
-
-Which of the three versions of the function should be used depends on
-the situation.  For most functions and implementation it is true that
-speed and precision do not go together.  I.e., the @code{float} versions
-are normally faster than the @code{double} and @code{long double}
-versions.  On the other hand the @code{long double} version has the
-highest precision.  One should always think about the actual needs and
-in case of double using @code{double} is a good compromise.
-
+@pindex complex.h
+
+All mathematical functions which take a floating-point argument
+have three variants, one each for @code{double}, @code{float}, and
+@code{long double} arguments.  The @code{double} versions are mostly
+defined in @w{ISO C 89}.  The @code{float} and @code{long double}
+versions are from the numeric extensions to C included in @w{ISO C 9X}.
+
+Which of the three versions of a function should be used depends on the
+situation.  For most calculations, the @code{float} functions are the
+fastest.  On the other hand, the @code{long double} functions have the
+highest precision.  @code{double} is somewhere in between.  It is
+usually wise to pick the narrowest type that can accomodate your data.
+Not all machines have a distinct @code{long double} type; it may be the
+same as @code{double}.
 
 @menu
-* Domain and Range Errors::      Detecting overflow conditions and the like.
-* Exceptions in Math Functions:: Signalling exception in math functions.
-* Mathematical Constants::       Precise numeric values for often used
-                                  constant.
-* FP Comparison Functions::      Special functions to compare floating-point
-                                  numbers.
-* FP Function Optimizations::    Fast code or small code.
-* Trig Functions::               Sine, cosine, and tangent.
-* Inverse Trig Functions::       Arc sine, arc cosine, and arc tangent.
-* Exponents and Logarithms::     Also includes square root.
-* Hyperbolic Functions::         Hyperbolic sine and friends.
-* Pseudo-Random Numbers::        Functions for generating pseudo-random
-				  numbers.
+* Mathematical Constants::      Precise numeric values for often-used
+                                 constants.
+* Trig Functions::              Sine, cosine, tangent, and friends.
+* Inverse Trig Functions::      Arcsine, arccosine, etc.
+* Exponents and Logarithms::    Also pow and sqrt.
+* Hyperbolic Functions::        sinh, cosh, tanh, etc.
+* Special Functions::           Bessel, gamma, erf.
+* Pseudo-Random Numbers::       Functions for generating pseudo-random
+				 numbers.
+* FP Function Optimizations::   Fast code or small code.
 @end menu
 
-@node Domain and Range Errors
-@section Domain and Range Errors
-
-@cindex domain error
-Many of the functions listed in this chapter are defined mathematically
-over a domain that is only a subset of real numbers.  For example, the
-@code{acos} function is defined over the domain between @code{@minus{}1} and
-@code{1}.  If you pass an argument to one of these functions that is
-outside the domain over which it is defined, the function sets
-@code{errno} to @code{EDOM} to indicate a @dfn{domain error}.  On
-machines that support @w{IEEE 754} floating point, functions reporting
-error @code{EDOM} also return a NaN.
-
-Some of these functions are defined mathematically to result in a
-complex value over parts of their domains.  The most familiar example of
-this is taking the square root of a negative number.  The functions in
-this chapter take only real arguments and return only real values;
-therefore, if the value ought to be nonreal, this is treated as a domain
-error.
-
-@cindex range error
-A related problem is that the mathematical result of a function may not
-be representable as a floating point number.  If magnitude of the
-correct result is too large to be represented, the function sets
-@code{errno} to @code{ERANGE} to indicate a @dfn{range error}, and
-returns a particular very large value (named by the macro
-@code{HUGE_VAL}) or its negation (@code{@minus{}HUGE_VAL}).
-
-If the magnitude of the result is too small, a value of zero is returned
-instead.  In this case, @code{errno} might or might not be
-set to @code{ERANGE}.
-
-The only completely reliable way to check for domain and range errors is
-to set @code{errno} to @code{0} before you call the mathematical function
-and test @code{errno} afterward.  As a consequence of this use of
-@code{errno}, use of the mathematical functions is not reentrant if you
-check for errors.
-
-@c ### This is no longer true.  --drepper
-@c None of the mathematical functions ever generates signals as a result of
-@c domain or range errors.  In particular, this means that you won't see
-@c @code{SIGFPE} signals generated within these functions.  (@xref{Signal
-@c Handling}, for more information about signals.)
-
-@comment math.h
-@comment ISO
-@deftypevr Macro double HUGE_VAL
-An expression representing a particular very large number.  On machines
-that use @w{IEEE 754}/@w{IEEE 854} floating point format, the value is
-``infinity''.  On other machines, it's typically the largest positive
-number that can be represented.
-
-The value of this macro is used as the return value from various
-mathematical @code{double} returning functions in overflow situations.
-@end deftypevr
-
-@comment math.h
-@comment ISO
-@deftypevr Macro float HUGE_VALF
-This macro is similar to the @code{HUGE_VAL} macro except that it is
-used by functions returning @code{float} values.
-
-This macro is introduced in @w{ISO C 9X}.
-@end deftypevr
-
-@comment math.h
-@comment ISO
-@deftypevr Macro {long double} HUGE_VALL
-This macro is similar to the @code{HUGE_VAL} macro except that it is
-used by functions returning @code{long double} values.  The value is
-only different from @code{HUGE_VAL} if the architecture really supports
-@code{long double} values.
-
-This macro is introduced in @w{ISO C 9X}.
-@end deftypevr
-
-
-A special case is the @code{ilogb} function @pxref{Exponents and
-Logarithms}.  Since the return value is an integer value, one cannot
-compare with @code{HUGE_VAL} etc.  Therefore two further values are
-defined.
-
-@comment math.h
-@comment ISO
-@deftypevr Macro int FP_ILOGB0
-This value is returned by @code{ilogb} if the argument is @code{0}.  The
-numeric value is either @code{INT_MIN} or @code{-INT_MAX}.
-
-This macro is introduced in @w{ISO C 9X}.
-@end deftypevr
-
-@comment math.h
-@comment ISO
-@deftypevr Macro int FP_ILOGBNAN
-This value is returned by @code{ilogb} if the argument is @code{NaN}.  The
-numeric value is either @code{INT_MIN} or @code{INT_MAX}.
-
-This macro is introduced in @w{ISO C 9X}.
-@end deftypevr
-
-
-For more information about floating-point representations and limits,
-see @ref{Floating Point Parameters}.  In particular, the macro
-@code{DBL_MAX} might be more appropriate than @code{HUGE_VAL} for many
-uses other than testing for an error in a mathematical function.
-
-
-@node Exceptions in Math Functions
-@section Exceptions in Math Functions
-@cindex exception
-@cindex signal
-
-Due to the restrictions in the size of the floating-point number
-representation or the limitation of the input range of certain functions
-some of the mathematical operations and functions have to signal
-exceptional situations.  The @w{IEEE 754} standard specifies which
-exceptions have to be supported and how they can be handled.
-
-@w{IEEE 754} specifies two actions for floating-point exception: taking
-a trap or continuing without doing so.  If the trap is taken a
-(possibly) user defined trap handler is called and this function can
-correct the argument or react somehow else on the call.  If the trap
-handler returns, its return value is taken as the result of the
-operation.
-
-If no trap handler is called each of the known exceptions has a default
-action.  This consists of setting a corresponding bit in the
-floating-point status word to indicate which kind of exception was
-raised and to return a default value, which depends on the exception
-(see the table below).
-
-@noindent
-The exceptions defined in @w{IEEE 754} are:
-
-@table @samp
-@item Invalid Operation
-This exception is raised if the given operands are invalid for the
-operation to be performed.  Examples are
-(see @w{IEEE 754}, @w{section 7}):
-@enumerate
-@item
-Any operation on a signalling NaN.
-@item
-Addition or subtraction; magnitude subtraction of infinities such as
-@math{(+@infinity{}) + (-@infinity{})}.
-@item
-Multiplication:
-@math{0 @mul{} @infinity{}}.
-
-@item
-Division: @math{0/0} or @math{@infinity{}/@infinity{}}.
-
-@item
-Remainder: @math{x} REM @math{y}, where @math{y} is zero or @math{x} is
-infinite.
-@item
-Square root if the operand is less then zero.
-@item
-Conversion of an internal floating-point number to an integer or to a
-decimal string when overflow, infinity, or NaN precludes a faithful
-representation in that format and this cannot otherwise be signaled.
-@item
-Conversion of an unrecognizable input string.
-@item
-Comparison via predicates involving @math{<} or @math{>}, without
-@code{?}, when the operands are @dfn{unordered}.  (@math{?>} means the
-unordered greater relation, @xref{FP Comparison Functions}).
-@end enumerate
-
-If the exception does not cause a trap handler to be called the result
-of the operation is taken as a quiet NaN.
-
-@item Division by Zero
-This exception is raised if the divisor is zero and the dividend is a
-finite nonzero number.  If no trap occurs the result is either
-@math{+@infinity{}} or @math{-@infinity{}}, depending on the
-signs of the operands.
-
-@item Overflow
-This exception is signalled whenever the result cannot be represented
-as a finite value in the precision format of the destination.  If no trap
-occurs the result depends on the sign of the intermediate result and the
-current rounding mode (@w{IEEE 754}, @w{section 7.3}):
-@enumerate
-@item
-Round to nearest carries all overflows to @math{@infinity{}}
-with the sign of the intermediate result.
-@item
-Round toward @math{0} carries all overflows to the precision's largest
-finite number with the sign of the intermediate result.
-@item
-Round toward @math{-@infinity{}} carries positive overflows to the
-precision's largest finite number and carries negative overflows to
-@math{-@infinity{}}.
-
-@item
-Round toward @math{@infinity{}} carries negative overflows to the
-precision's most negative finite number and carries positive overflows
-to @math{@infinity{}}.
-@end enumerate
-
-@item Underflow
-The underflow exception is created when an intermediate result is too
-small for the operation or if the operations result rounded to the
-destination precision causes a loss of accuracy by approximating the
-result by denormalized numbers.
-
-When no trap is installed for the underflow exception, underflow shall
-be signaled (via the underflow flag) only when both tininess and loss of
-accuracy have been detected.  If no trap handler is installed the
-operation continues with an inprecise small value or zero if the
-destination precision cannot hold the small exact result.
-
-@item Inexact
-This exception is signalled if the rounded result is not exact (such as
-computing the square root of two) or the result overflows without an
-overflow trap.
-@end table
-
-To control whether an exception causes a trap to occur all @w{IEEE 754}
-conformant floating-point implementations (either hardware or software)
-have a control word.  By setting specific bits for each exception in
-this control word the programmer can decide whether a trap is wanted or
-not.
-
-@w{ISO C 9X} introduces a set of function which can be used to control
-exceptions.  There are functions to manipulate the control word, to
-query the status word or to save and restore the whole state of the
-floating-point unit.  There are also functions to control the rounding
-mode used.
-
-@menu
-* Status bit operations::       Manipulate the FP status word.
-* FPU environment::             Controlling the status of the FPU.
-* Rounding Modes::              Controlling the rounding mode.
-@end menu
-
-@node Status bit operations
-@subsection Controlling the FPU status word
-
-To control the five types of exceptions defined in @w{IEEE 754} some
-functions are defined which abstract the interface to the FPU.  The
-actual implementation can be very different, depending on the underlying
-hardware or software.
-
-To address the single exception the @file{fenv.h} headers defines a
-number of macros:
-
-@vtable @code
-@comment fenv.h
-@comment ISO
-@item FE_INEXACT
-Represents the inexact exception iff the FPU supports this exception.
-@comment fenv.h
-@comment ISO
-@item FE_DIVBYZERO
-Represents the divide by zero exception iff the FPU supports this exception.
-@comment fenv.h
-@comment ISO
-@item FE_UNDERFLOW
-Represents the underflow exception iff the FPU supports this exception.
-@comment fenv.h
-@comment ISO
-@item FE_OVERFLOW
-Represents the overflow exception iff the FPU supports this exception.
-@comment fenv.h
-@comment ISO
-@item FE_INVALID
-Represents the invalid exception iff the FPU supports this exception.
-@end vtable
-
-The macro @code{FE_ALL_EXCEPT} is the bitwise OR of all exception macros
-which are supported by the FP implementation.
-
-Each of the supported exception flags can either be set or unset.  The
-@w{ISO C 9X} standard defines functions to set, unset and test the
-status of the flags.
-
-@comment fenv.h
-@comment ISO
-@deftypefun void feclearexcept (int @var{excepts})
-This function clears all of the supported exception flags denoted by
-@var{excepts} in the status word.
-@end deftypefun
-
-To safe the current status of the flags in the status word @file{fenv.h}
-defines the type @code{fexcept_t} which can hold all the information.
-The following function can be used to retrieve the current setting.
-
-@comment fenv.h
-@comment ISO
-@deftypefun void fegetexceptflag (fexcept_t *@var{flagp}, int @var{excepts})
-Store in the variable pointed to by @var{flagp} an
-implementation-defined value representing the current setting of the
-exception flags indicated by the parameter @var{excepts}.
-@end deftypefun
-
-@noindent
-To restore the previously saved values one can use this function:
-
-@comment fenv.h
-@comment ISO
-@deftypefun void fesetexceptflag (const fexcept_t *@var{flagp}, int @var{excepts})
-Restore from the variable pointed to by @var{flagp} the setting of the
-flags for the exceptions denoted by the value of the parameter
-@var{excepts}.
-@end deftypefun
-
-The last function allows to query the current status of the flags.  The
-flags can be set either explicitely (using @code{fesetexceptflag} or
-@code{feclearexcept}) or by a floating-point operation which happened
-before.  Since the flags are accumulative, the flags must be explicitely
-reset using @code{feclearexcept} if one wants to test for a certain
-exceptions raised by a specific piece of code.
-
-@comment fenv.h
-@comment ISO
-@deftypefun int fetestexcept (int @var{excepts})
-Test whether a subset of the flags indicated by the parameter
-@var{except} is currently set.  If yes, a nonzero value is returned
-which specifies which exceptions are set.  Otherwise the result is zero.
-@end deftypefun
-
-@noindent
-Code which uses the @code{fetestexcept} function could look like this:
-
-@smallexample
-@{
-  double f;
-  int raised;
-  feclearexcept (FE_ALL_EXCEPT);
-  f = compute ();
-  raised = fetestexcept (FE_OVERFLOW | FE_INVALID);
-  if (raised & FE_OVERFLOW) @{ /* ... */ @}
-  if (raised & FE_INVALID) @{ /* ... */ @}
-  /* ... */
-@}
-@end smallexample
-
-Please note that the return value of @code{fetestexcept} is @code{int}
-but this does not mean that the @code{fexcept_t} type is generally
-representable as an integer.  These are completely independent types.
-
-
-@node FPU environment
-@subsection Controlling the Floating-Point environment
-
-It is sometimes necessary so save the complete status of the
-floating-point unit for a certain time to perform some completely
-different actions.  Beside the status of the exception flags, the
-control word for the exceptions and the rounding mode can be saved.
-
-The file @file{fenv.h} defines the type @code{fenv_t}.  The layout of a
-variable of this type is implementation defined but the variable is able
-to contain the complete status information.  To fill a variable of this
-type one can use this function:
-
-@comment fenv.h
-@comment ISO
-@deftypefun void fegetenv (fenv_t *@var{envp})
-Store the current floating-point environment in the object pointed to by
-@var{envp}.
-@end deftypefun
-
-@noindent
-Another possibility which is useful in several situations is
-
-@comment fenv.h
-@comment ISO
-@deftypefun int feholdexcept (fenv_t *@var{envp})
-Store the current floating-point environment in the object pointed to by
-@var{envp}.  Afterwards, all exception flags are cleared and if
-available a mode is installed which continues on all exceptions and does
-not cause a trap to occur.  In this case a nonzero value is returned.
-
-If the floating-point implementation does not support such a non-stop
-mode, the return value is zero.
-@end deftypefun
-
-The functions which allow a state of the floating-point unit to be
-restored can take two kinds of arguments:
-
-@itemize @bullet
-@item
-Pointers to @code{fenv_t} objects which were initialized previously by a
-call to @code{fegetenv} or @code{feholdexcept}.
-@item
-@vindex FE_DFL_ENV
-The special macro @code{FE_DFL_ENV} which represents the floating-point
-environment as it was available at program start.
-@item
-Implementation defined macros with names starting with @code{FE_}.
-
-@vindex FE_NOMASK_ENV
-If possible, the GNU C Library defines a macro @code{FE_NOMASK_ENV}
-which represents an environment where no exceptions are masked, so every
-exception raised causes a trap to occur.  You can test for this macro
-using @code{#ifdef}.
-
-Some platforms might define other predefined environments.
-@end itemize
-
-@noindent
-To set any of the environments there are two functions defined.
-
-@deftypefun void fesetenv (const fenv_t *@var{envp})
-Establish the floating-point environment described in the object pointed
-to by @var{envp}.  Even if one or more exceptions flags in the restored
-environment are set no exception is raised.
-@end deftypefun
-
-In some situations the previous status of the exception flags must not
-simply be discarded and so this function is useful:
-
-@deftypefun void feupdateenv (const fenv_t *@var{envp})
-The current status of the floating-point unit is preserved in some
-automatic storage before the environment described by the object pointed
-to by @var{envp} is installed.  Once this is finished all exceptions set
-in the original environment which is saved in the automatic storage, is
-raised.
-@end deftypefun
-
-This function can be used to execute a part of the program with an
-environment which masks all exceptions and before switching back remove
-unwanted exception and raise the remaining exceptions.
-
-
-@node Rounding Modes
-@subsection Rounding modes of the Floating-Point Unit
-
-@w{IEEE 754} defines four different rounding modes.  If the rounding
-mode is supported by the floating-point implementation the corresponding
-of the following macros is defined:
-
-@table @code
-@comment fenv.h
-@comment ISO
-@vindex FE_TONEAREST
-@item FE_TONEAREST
-Round to nearest.  This is the default mode and should always be used
-except when a different mode is explicitely required.  Only rounding to
-nearest guarantees numeric stability of the computations.
-
-@comment fenv.h
-@comment ISO
-@vindex FE_UPWARD
-@item FE_UPWARD
-Round toward @math{+@infinity{}}.
-
-@comment fenv.h
-@comment ISO
-@vindex FE_DOWNWARD
-@item FE_DOWNWARD
-Round toward @math{-@infinity{}}.