Update.cvs/libc-ud-970915

1997-09-16 02:14  Ulrich Drepper  <drepper@cygnus.com>

	Implementation of Hesiod NSS module by Mark Kettenis.
	* hesiod/Makefile: New file.
	* hesiod/hesiod.c: New file.
	* hesiod/hesiod.h: New file.
	* hesiod/hesiod_p.h: New file.
	* hesiod/libnss_hesiod.map: New file.
	* hesiod/nss_hesiod/hesiod-grp.c: New file.
	* hesiod/nss_hesiod/hesiod-pwd.c: New file.
	* hesiod/nss_hesiod/hesiod-service.c: New file.
	* sysdeps/unix/inet/Subdirs: Add hesiod.

	* shlib-versions: Add version number for libnss_hesiod.

	* libio/iolibio.h: Remove definition of _IO_* macros.
	* libio/fileops.c: Define close, fstat, lseek, read, and write as
	macros to use __ protected versions.  Use those functions instead
	of _IO_* functions.
	* libio/iopopen.c: Define _IO_close to close.

	* manual/math.texi: Explain the use of the optimizing inline
	functions.
	Describe rand_r function and tell about SysV RNGs in introduction.

	* resolv/res_send.c (res_send): Use socklen_t type for `fromlen'
	variable.

	* string/Makefile (tests): Add noinl-tester.
	* string/noinl-tester.c: New file.
	* string/tester.c: Add more stpcpy tests for constant arguments for
	all short lengths.

	* string/string.h: Always declare __bzero.
	Describe __NO_STRING_INLINES.
	Always include <bits/string.h>.
	* string/bits/string2.h: Add warning about direct use.
	Change __strcpy_small and __stpcpy_small implementation to use
	macros and provide alternative for platforms which cannot do
	unaligned stores.
	* sysdeps/i386/bits/string.h: Don't define anything is
	__NO_STRING_INLINES is defined.
	* sysdeps/i386/i486/bits/string.h: Change __strcpy_small and
	__stpcpy_small implementation to use macros and provide
	alternative for platforms which cannot do unaligned stores.
	* sysdeps/alpha/bzero.S: Define bzero as weak alias of __bzero.
	* sysdeps/generic/bzero.c: Likewise.
	* sysdeps/i386/bzero.c: Likewise.
	* sysdeps/i386/i586/bzero.S: Likewise.
	* sysdeps/vax/bzero.s: Likewise.

	* sysdeps/generic/bits/select.h: Don't use ugly casts to access array.
	* sysdeps/i386/bits/select.h: Likewise.

	* sysdeps/i386/fpu/bits/mathinline.c (__finite): Relax register
	constraints a bit.
	Don't define and test for _BITS_MATHINLINE_H.  Emit warning if used
	directly and not through math.h.

	* sysdeps/i386/i486/atomicity.h: Change return type of compare_and_swap
	to char to get better code.  Fix typo.
	* sysdeps/stub/atomicity.h: Fix typo.

1997-09-14  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/generic/stpcpy.c: #undef stpcpy and __stpcpy.

1997-09-14  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* string/bits/string2.h: Add prototypes to avoid warning.

1997-09-14  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* string/bits/string2.h (strsep): Fix handling of empty REJECT.
	(__strsep_1c): Handle NULL and empty string.
	(__strsep_g): Likewise.

1997-09-13  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* catgets/Makefile (extra-objs): Set this instead of generated.

	* md5-crypt/Makefile (extra-objs): Add all object file variants of
	onlymd5-entry.

1997-09-12  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/generic/sysd-stdio.c (__stdio_read): Fix typo in last
	change.

1997-09-12  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/m68k/m68020/atomicity.h: New file.

1997-09-15 05:11  Ulrich Drepper  <drepper@cygnus.com>

	* posix/Makefile (distribute): Add globtest.c and globtest.sh.
	Compile and run globtest if not cross-compiling.
	* posix/globtest.c: New file.
	* posix/globtest.sh: New file.
	* posix/glob.c: Pretty print preprocessor stuff.
	(glob_in_dir): If PATTERN is not really a pattern still check
	whether it is a real file in the current directory and return
	error if not.
	Reported by Eugene Mamchits <eugin@ips.ras.ru>.

	* libio/fileops.c (_IO_file_sync): Acquire lock before doing the work.
	* libio/ioseekoff.c (_IO_seekoff): Likewise.
	* libio/ioseekpos.c (_IO_seekpos): Likewise.

1997-09-13 18:06  Ulrich Drepper  <drepper@cygnus.com>

	* configure.in: Prevent configuration for unsupported platforms.

1997-09-13 04:07  Ulrich Drepper  <drepper@cygnus.com>

	* elf/rtld.c (dl_main): Make sure we always have a file argument by
	testing for < 2 arguments after recognizing the options.

1997-09-12 11:47  Fila Kolodny  <fila@ibi.com>

	* string/bits/string2.h (__strsep_1c): Cast out const from __retval.
	(__strsep_g): Likewise.

1 files changed, 62 insertions, 2 deletions

diff --git a/manual/math.texi b/manual/math.texi
index 2b7cb82..15a2075 100644
--- a/manual/math.texi
+++ b/manual/math.texi
@@ -54,6 +54,7 @@ in case of double using @code{double} is a good compromise.
                                   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.
@@ -704,6 +705,35 @@ that the comparison for equality and unequality do @emph{not} throw an
 exception if one of the arguments is an unordered value.
 
 
+@node FP Function Optimizations
+@section Is Fast Code or Small Code preferred?
+@cindex Optimization
+
+If an application uses many floating point function it is often the case
+that the costs for the function calls itseld are not neglectable.
+Modern processor implementation often can execute the operation itself
+very fast but the call means a disturbance of the control flow.
+
+For this reason the GNU C Library provides optimizations for many of the
+frequently used math functions.  When the GNU CC is used and the user
+activates the optimizer several new inline functions and macros get
+defined.  These new functions and macros have the same names as the
+library function and so get used instead of the later.  In case of
+inline functions the compiler will decide whether it is reasonable to
+use the inline function and this decision is usually correct.
+
+For the generated code this means that no calls to the library functions
+are necessary.  This increases the speed significantly.  But the
+drawback is that the code size increases and this increase is not always
+neglectable.
+
+In cases where the inline functions and macros are not wanted the symbol
+@code{__NO_MATH_INLINES} should be defined before any system header is
+included.  This will make sure only library functions are used.  Of
+course it can be determined for each single file in the project whether
+giving this option is preferred or not.
+
+
 @node Trig Functions
 @section Trigonometric Functions
 @cindex trigonometric functions
@@ -1430,8 +1460,14 @@ the same seed, used in different C libraries or on different CPU types,
 will give you different random numbers.
 
 The GNU library supports the standard @w{ISO C} random number functions
-plus another set derived from BSD.  We recommend you use the standard
-ones, @code{rand} and @code{srand}.
+plus two other sets derived from BSD and SVID.  We recommend you use the
+standard ones, @code{rand} and @code{srand} if only a small number of
+random bits are required.  The SVID functions provide an interface which
+allows better randon number generator algorithms and they return up to
+48 random bits in one calls and they also return random floating-point
+numbers if wanted.  The SVID function might not be available on some BSD
+derived systems but since they are required in the XPG they are
+available on all Unix-conformant systems.
 
 @menu
 * ISO Random::       @code{rand} and friends.
@@ -1478,6 +1514,30 @@ To produce truly random numbers (not just pseudo-random), do @code{srand
 (time (0))}.
 @end deftypefun
 
+A completely broken interface was designed by the POSIX.1 committee to
+support reproducible random numbers in multi-threaded programs.
+
+@comment stdlib.h
+@comment POSIX.1
+@deftypefun int rand_r (unsigned int *@var{seed})
+This function returns a random number in the range 0 to @code{RAND_MAX}
+just as @code{rand} does.  But this function does not keep an internal
+state for the RNG.  Instead the @code{unsigned int} variable pointed to
+by the argument @var{seed} is the only state.  Before the value is
+returned the state will be updated so that the next call will return a
+new number.
+
+I.e., the state of the RNG can only have as much bits as the type
+@code{unsigned int} has.  This is far too few to provide a good RNG.
+This interface is broken by design.
+
+If the program requires reproducible random numbers in multi-threaded
+programs the reentrant SVID functions are probably a better choice.  But
+these functions are GNU extensions and therefore @code{rand_r}, as being
+standardized in POSIX.1, should always be kept as a default method.
+@end deftypefun
+
+
 @node BSD Random
 @subsection BSD Random Number Functions