2009-03-25 Craig Howland <howland@LGSInnovations.com>

	* libc/include/math.h:  (llround, llroundf): Declare.
	* libm/common/s_llround.c: New file, implementing llround().
	* libm/common/sf_llround.c: New file, implementing llroundf().
	* libm/common/sf_lround.c: Remove spurious cast in _DOUBLE_IS_32BITS
	version of function.
	* libm/common/sf_lrint.c: Ditto.
	* libm/common/sf_logb.c:  Corrected return for subnormal argument
	by replacing existing function with a version created from sf_ilogb.c.
	* libm/common/s_logb.c: Ditto, except starting point s_ilogb.c.  Also
	added documentation for logb() and logbf().
	* libm/common/s_signbit.c:  Add signbit() documentation.
	* libm/common/s_log2.c: Update return values to match what w_log2.c has,
	since log2 uses log(); add note about being derived instead of direct.
	* libm/common/sf_fma.c: Add casts to attempt to get correct results,
	as well as comments pointing out problems with the implementation.
	* libm/common/s_fma.c: Add fma() and fmaf() documentation.
	* libm/common/sf_remquo.c: Incorrect quotient returns for large values
	corrected by discarding existing function and replacing with Sun
	verion, with some enhancements.
	* libm/common/s_remquo.c: Ditto.  Add remquo() and remquof()
	documentation.
	* libm/common/s_fmax.c: Add fmax() and fmaxf() documentation.
	* libm/common/s_fmin.c: Add fmin() and fminf() documentation.
	* libm/common/s_fdim.c: Return NAN for NAN arg, add fdim() and fdimf()
	documentation.
	* libm/common/sf_fdim.c: Return NAN for NAN arg, HUGE_VALF for inf arg.
	* libm/common/s_trunc.c: Add trunc() and truncf() documentation.
	* libm/common/s_rint.c: Add rint() and rintf() documentation.
	* libm/common/s_round.c: Add round() and roundf() documentation.
	* libm/common/s_scalbn.c: Add scalbln() and scalblnf() documentation.
	* libm/common/s_infinity.c: Add infinity() and infinityf()
	documentation.
	* libm/common/s_lround.c: Add lround(), lroundf(), llround(), and
	llroundf() documentation.
	* libm/common/s_lrint.c: Add lrint(), lrintf(), llrint(), and llrintf()
	documentation.
	* libm/common/isgreater.c: New file for documenting math.h function-like
	macros isgreater(), isgreaterequal(), isless(), islessequal(),
	islessgreater(), and isunordered().
	* libm/common/s_isnan.c: Add documentation for function-like macros
	fpclassify(), isfinite(), isinf(), isnan(), and isnormal().
	* libm/common/s_nearbyint.c: Add nearbyint() and nearbyintf()
	documentation.
	* libm/common/Makefile.am: Add s_llround.c (src); sf_llround.c (fsrc);
	s_fdim.def, s_fma.def, s_fmax.def, s_fmin.def,
	s_logb.def, s_lrint.def, s_lround.def, s_nearbyint.def, s_remquo.def,
        s_rint.def, s_round.def, s_signbit.def, s_trunc.def, and
        isgreater.def (chobj);
	re-name all existing chew files (chobj) to match source file base
	names (put in underscores), delete all special targets for chew files
	(leaving all to be generated by rule).
	* libm/common/Makefile.in: regenerate.
	* libm/math/w_exp2.c: Add "base 2" to documentation description (and
	delete TRAD_SYNOPSIS).
	* libm/math/w_gamma.c: Add tgamma() and tgammaf() documentation, along
	with some history behind the function names.
	* libm/math/math.tex: Add includes for newly-added documentation (see
	.def additions to common/Makefile.am and math/Makefile.am in this
	ChangeLog list), adjusted existing .def file names to match source file
	base names (added underscores); add mention of HUGE_VALF; rename
	"Version of library" section to "Error Handling" and add some text
	about floating-point exception; added section "Standards Compliance And
	Portability".
	* libm/math/Makefile.am: Add w_exp2.def (chobj);
	re-name all existing chew files (chobj) to match source file base
	names, delete all special targets for chew files (leaving all to be
	generated by rule).
	* libm/math/Makefile.in: regenerated
	* doc/makedoc.c: Change silent ignoring of commands < 5 characters
	to a failure when reading macro file for commands < 4 characters;
	add -v (verbose) option for printing some debugging information;
	get rid of spurious translation of "@*" to "*" (no source files used @*,
	so no existing doc pages were affected); clean up some compiler
	warnings.
	* doc/doc.str: add BUGS and SEEALSO sections (to match texi2pod.pl
	which has them); Remove ITEM command (redundant with makedoc built-in
	"o", not used in any present source file so nothing is lost, anyway).
	* HOWTO: New file to hold information for maintainers regarding how
	to do things.  Initial sections on documentation and ELIX levels.

1 files changed, 29 insertions, 17 deletions

diff --git a/newlib/libm/common/s_log2.c b/newlib/libm/common/s_log2.c
index 4683960eb..7ad2cd88b 100644
--- a/newlib/libm/common/s_log2.c
+++ b/newlib/libm/common/s_log2.c
@@ -14,7 +14,7 @@
 
 /*
 FUNCTION
-	<<log2>>, <<log2f>>---base 2 logarithm
+	<<log2>>, <<log2f>>--base 2 logarithm
 INDEX
 	log2
 INDEX
@@ -25,28 +25,40 @@ ANSI_SYNOPSIS
 	double log2(double <[x]>);
 	float log2f(float <[x]>);
 
-TRAD_SYNOPSIS
-	#include <math.h>
-	double log2(<[x]>);
-	double <[x]>;
-
-	float log2f(<[x]>);
-	float <[x]>;
-
 DESCRIPTION
-	<<log2>> returns the base 2 logarithm of <[x]>.
+The <<log2>> functions compute the base-2 logarithm of <[x]>.  A domain error
+occurs if the argument is less than zero.  A range error occurs if the
+argument is zero.
+
+The Newlib implementations are not full, intrinisic calculations, but
+rather are derivatives based on <<log>>.  (Accuracy might be slightly off from
+a direct calculation.)  In addition to functions, they are also implemented as
+macros defined in math.h:
+. #define log2(x) (log (x) / _M_LOG2_E)
+. #define log2f(x) (logf (x) / (float) _M_LOG2_E)
+To use the functions instead, just undefine the macros first.
 
-	<<log2f>> is identical, save that it takes and returns <<float>> values.
+You can use the (non-ANSI) function <<matherr>> to specify error
+handling for these functions, indirectly through the respective <<log>>
+function. 
 
 RETURNS
-	On success, <<log2>> and <<log2f>> return the calculated value.
-	If the result underflows, the returned value is <<0>>.  If the
-	result overflows, the returned value is <<HUGE_VAL>>.  In
-	either case, <<errno>> is set to <<ERANGE>>.
+The <<log2>> functions return
+@ifnottex
+<<log base-2(<[x]>)>>
+@end ifnottex
+@tex
+$log_2(x)$
+@end tex
+on success.
+When <[x]> is zero, the
+returned value is <<-HUGE_VAL>> and <<errno>> is set to <<ERANGE>>.
+When <[x]> is negative, the returned value is NaN (not a number) and
+<<errno>> is set to <<EDOM>>.  You can control the error behavior via
+<<matherr>>.
 
 PORTABILITY
-	<<log2>> and <<log2f>> are required by ISO/IEC 9899:1999 and the
-	System V Interface Definition (Issue 6).
+C99, POSIX, System V Interface Definition (Issue 6).
 */
 
 /*