From 139f923bb4564fb021dce2b7ae460a3d8e3bb87d Mon Sep 17 00:00:00 2001 From: Jeff Johnston Date: Wed, 25 Mar 2009 19:13:24 +0000 Subject: 2009-03-25 Craig Howland * 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. --- newlib/libm/math/Makefile.am | 104 ++----------------- newlib/libm/math/Makefile.in | 104 ++----------------- newlib/libm/math/math.tex | 237 ++++++++++++++++++++----------------------- newlib/libm/math/w_exp2.c | 13 +-- newlib/libm/math/w_gamma.c | 53 ++++++++-- 5 files changed, 175 insertions(+), 336 deletions(-) (limited to 'newlib/libm/math') diff --git a/newlib/libm/math/Makefile.am b/newlib/libm/math/Makefile.am index 6682541..3358179 100644 --- a/newlib/libm/math/Makefile.am +++ b/newlib/libm/math/Makefile.am @@ -65,14 +65,14 @@ endif # USE_LIBTOOL include $(srcdir)/../../Makefile.shared -chobj = wacos.def wacosh.def wasin.def sasinh.def \ - satan.def watan2.def watanh.def wj0.def \ - wcosh.def serf.def wexp.def \ - sfabs.def sfloor.def wfmod.def sfrexp.def \ - wgamma.def whypot.def sldexp.def wlog.def \ - wlog10.def \ - wpow.def wremainder.def ssin.def wsinh.def \ - wsqrt.def stan.def stanh.def +chobj = w_acos.def w_acosh.def w_asin.def s_asinh.def \ + s_atan.def w_atan2.def w_atanh.def w_j0.def \ + w_cosh.def s_erf.def w_exp.def w_exp2.def \ + s_fabs.def s_floor.def w_fmod.def s_frexp.def \ + w_gamma.def w_hypot.def s_ldexp.def w_log.def \ + w_log10.def \ + w_pow.def w_remainder.def s_sin.def w_sinh.def \ + w_sqrt.def s_tan.def s_tanh.def SUFFIXES = .def @@ -89,94 +89,6 @@ doc: $(chobj) CLEANFILES = $(chobj) *.ref -# Texinfo does not appear to support underscores in file names, so we -# name the .def files without underscores. - -wacos.def: w_acos.c - $(CHEW) < $(srcdir)/w_acos.c >$@ 2>/dev/null - touch stmp-def -wacosh.def: w_acosh.c - $(CHEW) < $(srcdir)/w_acosh.c >$@ 2>/dev/null - touch stmp-def -wasin.def: w_asin.c - $(CHEW) < $(srcdir)/w_asin.c >$@ 2>/dev/null - touch stmp-def -sasinh.def: s_asinh.c - $(CHEW) < $(srcdir)/s_asinh.c >$@ 2>/dev/null - touch stmp-def -satan.def: s_atan.c - $(CHEW) < $(srcdir)/s_atan.c >$@ 2>/dev/null - touch stmp-def -watan2.def: w_atan2.c - $(CHEW) < $(srcdir)/w_atan2.c >$@ 2>/dev/null - touch stmp-def -watanh.def: w_atanh.c - $(CHEW) < $(srcdir)/w_atanh.c >$@ 2>/dev/null - touch stmp-def -wj0.def: w_j0.c - $(CHEW) < $(srcdir)/w_j0.c >$@ 2>/dev/null - touch stmp-def -scopysign.def: s_copysign.c - $(CHEW) < $(srcdir)/../common/s_copysign.c >$@ 2>/dev/null - touch stmp-def -wcosh.def: w_cosh.c - $(CHEW) < $(srcdir)/w_cosh.c >$@ 2>/dev/null - touch stmp-def -serf.def: s_erf.c - $(CHEW) < $(srcdir)/s_erf.c >$@ 2>/dev/null - touch stmp-def -wexp.def: w_exp.c - $(CHEW) < $(srcdir)/w_exp.c >$@ 2>/dev/null - touch stmp-def -sfabs.def: s_fabs.c - $(CHEW) < $(srcdir)/s_fabs.c >$@ 2>/dev/null - touch stmp-def -sfloor.def: s_floor.c - $(CHEW) < $(srcdir)/s_floor.c >$@ 2>/dev/null - touch stmp-def -wfmod.def: w_fmod.c - $(CHEW) < $(srcdir)/w_fmod.c >$@ 2>/dev/null - touch stmp-def -sfrexp.def: s_frexp.c - $(CHEW) < $(srcdir)/s_frexp.c >$@ 2>/dev/null - touch stmp-def -wgamma.def: w_gamma.c - $(CHEW) < $(srcdir)/w_gamma.c >$@ 2>/dev/null - touch stmp-def -whypot.def: w_hypot.c - $(CHEW) < $(srcdir)/w_hypot.c >$@ 2>/dev/null - touch stmp-def -sldexp.def: s_ldexp.c - $(CHEW) < $(srcdir)/s_ldexp.c >$@ 2>/dev/null - touch stmp-def -wlog.def: w_log.c - $(CHEW) < $(srcdir)/w_log.c >$@ 2>/dev/null - touch stmp-def -wlog10.def: w_log10.c - $(CHEW) < $(srcdir)/w_log10.c >$@ 2>/dev/null - touch stmp-def -wpow.def: w_pow.c - $(CHEW) < $(srcdir)/w_pow.c >$@ 2>/dev/null - touch stmp-def -wremainder.def: w_remainder.c - $(CHEW) < $(srcdir)/w_remainder.c >$@ 2>/dev/null - touch stmp-def -ssin.def: s_sin.c - $(CHEW) < $(srcdir)/s_sin.c >$@ 2>/dev/null - touch stmp-def -wsinh.def: w_sinh.c - $(CHEW) < $(srcdir)/w_sinh.c >$@ 2>/dev/null - touch stmp-def -wsqrt.def: w_sqrt.c - $(CHEW) < $(srcdir)/w_sqrt.c >$@ 2>/dev/null - touch stmp-def -stan.def: s_tan.c - $(CHEW) < $(srcdir)/s_tan.c >$@ 2>/dev/null - touch stmp-def -stanh.def: s_tanh.c - $(CHEW) < $(srcdir)/s_tanh.c >$@ 2>/dev/null - touch stmp-def - # A partial dependency list. $(lib_a_OBJECTS): $(srcdir)/../../libc/include/math.h $(srcdir)/../common/fdlibm.h diff --git a/newlib/libm/math/Makefile.in b/newlib/libm/math/Makefile.in index 5996238..c0c3167 100644 --- a/newlib/libm/math/Makefile.in +++ b/newlib/libm/math/Makefile.in @@ -373,14 +373,14 @@ libmath_la_LDFLAGS = -Xcompiler -nostdlib @USE_LIBTOOL_FALSE@noinst_LIBRARIES = lib.a @USE_LIBTOOL_FALSE@lib_a_SOURCES = $(src) $(fsrc) @USE_LIBTOOL_FALSE@lib_a_CFLAGS = $(AM_CFLAGS) -chobj = wacos.def wacosh.def wasin.def sasinh.def \ - satan.def watan2.def watanh.def wj0.def \ - wcosh.def serf.def wexp.def \ - sfabs.def sfloor.def wfmod.def sfrexp.def \ - wgamma.def whypot.def sldexp.def wlog.def \ - wlog10.def \ - wpow.def wremainder.def ssin.def wsinh.def \ - wsqrt.def stan.def stanh.def +chobj = w_acos.def w_acosh.def w_asin.def s_asinh.def \ + s_atan.def w_atan2.def w_atanh.def w_j0.def \ + w_cosh.def s_erf.def w_exp.def w_exp2.def \ + s_fabs.def s_floor.def w_fmod.def s_frexp.def \ + w_gamma.def w_hypot.def s_ldexp.def w_log.def \ + w_log10.def \ + w_pow.def w_remainder.def s_sin.def w_sinh.def \ + w_sqrt.def s_tan.def s_tanh.def SUFFIXES = .def CHEW = ../../doc/makedoc -f $(srcdir)/../../doc/doc.str @@ -1424,94 +1424,6 @@ objectlist.awk.in: $(noinst_LTLIBRARIES) doc: $(chobj) cat $(srcdir)/math.tex >> $(TARGETDOC) -# Texinfo does not appear to support underscores in file names, so we -# name the .def files without underscores. - -wacos.def: w_acos.c - $(CHEW) < $(srcdir)/w_acos.c >$@ 2>/dev/null - touch stmp-def -wacosh.def: w_acosh.c - $(CHEW) < $(srcdir)/w_acosh.c >$@ 2>/dev/null - touch stmp-def -wasin.def: w_asin.c - $(CHEW) < $(srcdir)/w_asin.c >$@ 2>/dev/null - touch stmp-def -sasinh.def: s_asinh.c - $(CHEW) < $(srcdir)/s_asinh.c >$@ 2>/dev/null - touch stmp-def -satan.def: s_atan.c - $(CHEW) < $(srcdir)/s_atan.c >$@ 2>/dev/null - touch stmp-def -watan2.def: w_atan2.c - $(CHEW) < $(srcdir)/w_atan2.c >$@ 2>/dev/null - touch stmp-def -watanh.def: w_atanh.c - $(CHEW) < $(srcdir)/w_atanh.c >$@ 2>/dev/null - touch stmp-def -wj0.def: w_j0.c - $(CHEW) < $(srcdir)/w_j0.c >$@ 2>/dev/null - touch stmp-def -scopysign.def: s_copysign.c - $(CHEW) < $(srcdir)/../common/s_copysign.c >$@ 2>/dev/null - touch stmp-def -wcosh.def: w_cosh.c - $(CHEW) < $(srcdir)/w_cosh.c >$@ 2>/dev/null - touch stmp-def -serf.def: s_erf.c - $(CHEW) < $(srcdir)/s_erf.c >$@ 2>/dev/null - touch stmp-def -wexp.def: w_exp.c - $(CHEW) < $(srcdir)/w_exp.c >$@ 2>/dev/null - touch stmp-def -sfabs.def: s_fabs.c - $(CHEW) < $(srcdir)/s_fabs.c >$@ 2>/dev/null - touch stmp-def -sfloor.def: s_floor.c - $(CHEW) < $(srcdir)/s_floor.c >$@ 2>/dev/null - touch stmp-def -wfmod.def: w_fmod.c - $(CHEW) < $(srcdir)/w_fmod.c >$@ 2>/dev/null - touch stmp-def -sfrexp.def: s_frexp.c - $(CHEW) < $(srcdir)/s_frexp.c >$@ 2>/dev/null - touch stmp-def -wgamma.def: w_gamma.c - $(CHEW) < $(srcdir)/w_gamma.c >$@ 2>/dev/null - touch stmp-def -whypot.def: w_hypot.c - $(CHEW) < $(srcdir)/w_hypot.c >$@ 2>/dev/null - touch stmp-def -sldexp.def: s_ldexp.c - $(CHEW) < $(srcdir)/s_ldexp.c >$@ 2>/dev/null - touch stmp-def -wlog.def: w_log.c - $(CHEW) < $(srcdir)/w_log.c >$@ 2>/dev/null - touch stmp-def -wlog10.def: w_log10.c - $(CHEW) < $(srcdir)/w_log10.c >$@ 2>/dev/null - touch stmp-def -wpow.def: w_pow.c - $(CHEW) < $(srcdir)/w_pow.c >$@ 2>/dev/null - touch stmp-def -wremainder.def: w_remainder.c - $(CHEW) < $(srcdir)/w_remainder.c >$@ 2>/dev/null - touch stmp-def -ssin.def: s_sin.c - $(CHEW) < $(srcdir)/s_sin.c >$@ 2>/dev/null - touch stmp-def -wsinh.def: w_sinh.c - $(CHEW) < $(srcdir)/w_sinh.c >$@ 2>/dev/null - touch stmp-def -wsqrt.def: w_sqrt.c - $(CHEW) < $(srcdir)/w_sqrt.c >$@ 2>/dev/null - touch stmp-def -stan.def: s_tan.c - $(CHEW) < $(srcdir)/s_tan.c >$@ 2>/dev/null - touch stmp-def -stanh.def: s_tanh.c - $(CHEW) < $(srcdir)/s_tanh.c >$@ 2>/dev/null - touch stmp-def - # A partial dependency list. $(lib_a_OBJECTS): $(srcdir)/../../libc/include/math.h $(srcdir)/../common/fdlibm.h diff --git a/newlib/libm/math/math.tex b/newlib/libm/math/math.tex index 7bc56ce..608268a 100644 --- a/newlib/libm/math/math.tex +++ b/newlib/libm/math/math.tex @@ -9,6 +9,7 @@ Two definitions from @file{math.h} are of particular interest. @item The representation of infinity as a @code{double} is defined as @code{HUGE_VAL}; this number is returned on overflow by many functions. +The macro @code{HUGE_VALF} is a corresponding value for @code{float}. @item The structure @code{exception} is used when you write customized error @@ -44,43 +45,59 @@ machines---are available when you include @file{fastmath.h} instead of * atan:: Arctangent * atan2:: Arctangent of y/x * atanh:: Inverse hyperbolic tangent -* jN:: Bessel functions (jN, yN) +* jN:: Bessel functions (jN, yN) * cbrt:: Cube root * copysign:: Sign of Y, magnitude of X * cosh:: Hyperbolic cosine -* erf:: Error function (erf, erfc) -* exp:: Exponential -* expm1:: Exponential of x, - 1 +* erf:: Error function (erf, erfc) +* exp:: Exponential, base e +* exp2:: Exponential, base 2 +* expm1:: Exponential, base e, of x - 1 * fabs:: Absolute value (magnitude) -* floor:: Floor and ceiling (floor, ceil) +* fdim:: Positive difference +* floor:: Floor and ceiling (floor, ceil) +* fma:: Floating multiply add +* fmax:: Maximum +* fmin:: Minimum * fmod:: Floating-point remainder (modulo) +* fpclassify:: Floating-point classification macro * frexp:: Split floating-point number * gamma:: Logarithmic gamma function * hypot:: Distance from origin * ilogb:: Get exponent * infinity:: Floating infinity -* isnan:: Check type of number -* ldexp:: Load exponent +* isgreater:: Comparison macros +* ldexp:: Scale by a power of 2 * log:: Natural logarithms * log10:: Base 10 logarithms * log1p:: Log of 1 + X +* log2:: Base 2 logarithms +* logb:: Get exponent +* lrint:: Round to integer +* lround:: Round to integer, away from zero (lround, llround) * matherr:: Modifiable math error handler * modf:: Split fractional and integer parts * nan:: Floating Not a Number +* nearbyint:: Round to integer * nextafter:: Get next representable number * pow:: X to the power Y * remainder:: remainder of X divided by Y -* scalbn:: scalbn +* remquo:: Remainder and part of quotient +* rint:: Round to integer +* round:: Round to integer, away from zero +* scalbn:: Scale by a power of FLT_RADIX (2) +* signbit:: Does floating-point number have negative sign? * sin:: Sine or cosine (sin, cos) * sinh:: Hyperbolic sine * sqrt:: Positive square root * tan:: Tangent * tanh:: Hyperbolic tangent +* trunc:: Round to integer, towards zero @end menu @page @node version -@section Version of library +@section Error Handling There are four different versions of the math library routines: IEEE, POSIX, X/Open, or SVID. The version may be selected at runtime by @@ -114,119 +131,89 @@ log: DOMAIN error The library is set to X/Open mode by default. -@page -@include math/wacos.def - -@page -@include math/wacosh.def - -@page -@include math/wasin.def - -@page -@include math/sasinh.def - -@page -@include math/satan.def - -@page -@include math/watan2.def - -@page -@include math/watanh.def - -@page -@include math/wj0.def - -@page -@include common/scbrt.def - -@page -@include common/scopysign.def - -@page -@include math/wcosh.def - -@page -@include math/serf.def - -@page -@include math/wexp.def - -@page -@include common/sexpm1.def - -@page -@include math/sfabs.def - -@page -@include math/sfloor.def - -@page -@include math/wfmod.def - -@page -@include math/sfrexp.def - -@page -@include math/wgamma.def - -@page -@include math/whypot.def - -@page -@include common/silogb.def - -@page -@include common/sinfinity.def - -@page -@include common/sisnan.def - -@page -@include math/sldexp.def - -@page -@include math/wlog.def - -@page -@include math/wlog10.def - -@page -@include common/slog1p.def - -@page -@include common/smatherr.def - -@page -@include common/smodf.def - -@page -@include common/snan.def - -@page -@include common/snextafter.def - -@page -@include math/wpow.def - -@page -@include math/wremainder.def - -@page -@include common/sscalbn.def - -@page -@include math/wsqrt.def - -@page -@include math/ssin.def - -@page -@include math/wsinh.def - -@page -@include math/stan.def - -@page -@include math/stanh.def +The aforementioned error reporting is the supported Newlib libm error +handling method. However, the majority of the functions are written +so as to produce the floating-point exceptions (e.g. "invalid", +"divide-by-zero") as required by the C and POSIX standards, for +floating-point implementations that support them. Newlib does not provide +the floating-point exception access routines defined in the standards +for fenv.h, though, which is why they are considered unsupported. It is +mentioned in case you have separately-provided access routines so that +you are aware that they can be caused. + +@section Standards Compliance And Portability +Most of the individual function descriptions describe the standards to which +each function complies. However, these descriptions are mostly out of date, +having been written before C99 was released. One of these days we'll get +around to updating the rest of them. (If you'd like to help, please let us +know.) + +``C99'' refers to ISO/IEC 9899:1999, ``Programming languages--C''. +``POSIX'' refers to IEEE Standard 1003.1. POSIX@registeredsymbol{} is a +registered trademark of The IEEE. + +@c To sort the include list easily, keep the indentation right because want to +@c skip the s_|w_ at the start of most--but not all--of the file names. +@c (e.g., isgreater.def does not have a leading s nor w.) Then, sort +@c based on the column. For example: "sort -t@ -k3.17" +@c A few hand-edits might be appropriate after a sort, although not necessary +@c and are a nuisance as ought to be kept in sync with menu list above: +@c atan2 after atan, exp2 after exp, log first in log list, and w_j0 to place +@c to reflect function name of Bessel (as opposed to j; e.g. after atanh, +@c before cbrt). + +@page @include math/w_acos.def +@page @include math/w_acosh.def +@page @include math/w_asin.def +@page @include math/s_asinh.def +@page @include math/s_atan.def +@page @include math/w_atan2.def +@page @include math/w_atanh.def +@page @include math/w_j0.def +@page @include common/s_cbrt.def +@page @include common/s_copysign.def +@page @include math/w_cosh.def +@page @include math/s_erf.def +@page @include math/w_exp.def +@page @include math/w_exp2.def +@page @include common/s_expm1.def +@page @include math/s_fabs.def +@page @include common/s_fdim.def +@page @include math/s_floor.def +@page @include common/s_fma.def +@page @include common/s_fmax.def +@page @include common/s_fmin.def +@page @include math/w_fmod.def +@page @include math/s_frexp.def +@page @include math/w_gamma.def +@page @include math/w_hypot.def +@page @include common/s_ilogb.def +@page @include common/s_infinity.def +@page @include common/isgreater.def +@page @include common/s_isnan.def +@page @include math/s_ldexp.def +@page @include math/w_log.def +@page @include math/w_log10.def +@page @include common/s_log1p.def +@page @include common/s_log2.def +@page @include common/s_logb.def +@page @include common/s_lrint.def +@page @include common/s_lround.def +@page @include common/s_matherr.def +@page @include common/s_modf.def +@page @include common/s_nan.def +@page @include common/s_nearbyint.def +@page @include common/s_nextafter.def +@page @include math/w_pow.def +@page @include math/w_remainder.def +@page @include common/s_remquo.def +@page @include common/s_rint.def +@page @include common/s_round.def +@page @include common/s_scalbn.def +@page @include common/s_signbit.def +@page @include math/s_sin.def +@page @include math/w_sinh.def +@page @include math/w_sqrt.def +@page @include math/s_tan.def +@page @include math/s_tanh.def +@page @include common/s_trunc.def diff --git a/newlib/libm/math/w_exp2.c b/newlib/libm/math/w_exp2.c index ed0bc39..efb676d 100644 --- a/newlib/libm/math/w_exp2.c +++ b/newlib/libm/math/w_exp2.c @@ -13,7 +13,7 @@ /* FUNCTION - <>, <>---exponential + <>, <>--exponential, base 2 INDEX exp2 INDEX @@ -24,14 +24,6 @@ ANSI_SYNOPSIS double exp2(double <[x]>); float exp2f(float <[x]>); -TRAD_SYNOPSIS - #include - double exp2(<[x]>); - double <[x]>; - - float exp2f(<[x]>); - float <[x]>; - DESCRIPTION <> and <> calculate 2 ^ <[x]>, that is, @ifnottex @@ -50,6 +42,9 @@ RETURNS result overflows, the returned value is <>. In either case, <> is set to <>. +PORTABILITY + ANSI C, POSIX. + */ /* diff --git a/newlib/libm/math/w_gamma.c b/newlib/libm/math/w_gamma.c index fad4049..3717f53 100644 --- a/newlib/libm/math/w_gamma.c +++ b/newlib/libm/math/w_gamma.c @@ -12,11 +12,20 @@ * */ +/* BUG: FIXME? + According to Linux man pages for tgamma, lgamma, and gamma, the gamma +function was originally defined in BSD as implemented here--the log of the gamma +function. BSD 4.3 changed the name to lgamma, apparently removing gamma. BSD +4.4 re-introduced the gamma name with the more intuitive, without logarithm, +plain gamma function. The C99 standard apparently wanted to avoid a problem +with the poorly-named earlier gamma and used tgamma when adding a plain +gamma function. + So the current gamma is matching an old, bad definition, and not +matching a newer, better definition. */ /* FUNCTION - <>, <>, <>, <>, <>, - <>, <>, <>---logarithmic gamma - function + <>, <>, <>, <>, <>, <>, <>, <>, <>, and <>--logarithmic and plain gamma functions + INDEX gamma INDEX @@ -33,6 +42,10 @@ INDEX lgamma_r INDEX lgammaf_r +INDEX +tgamma +INDEX +tgammaf ANSI_SYNOPSIS #include @@ -44,6 +57,8 @@ double gamma_r(double <[x]>, int *<[signgamp]>); float gammaf_r(float <[x]>, int *<[signgamp]>); double lgamma_r(double <[x]>, int *<[signgamp]>); float lgammaf_r(float <[x]>, int *<[signgamp]>); +double tgamma(double <[x]>); +float tgammaf(float <[x]>); TRAD_SYNOPSIS #include @@ -67,15 +82,19 @@ int <[signgamp]>; float lgammaf_r(<[x]>, <[signgamp]>) float <[x]>; int <[signgamp]>; +double tgamma(<[x]>) +double <[x]>; +float tgammaf(<[x]>) +float <[x]>; DESCRIPTION -<> calculates +<> calculates @tex -$\mit ln\bigl(\Gamma(x)\bigr)$, +$\mit ln\bigl(\Gamma(x)\bigr)$, @end tex the natural logarithm of the gamma function of <[x]>. The gamma function (<))>>) is a generalization of factorial, and retains -the property that +the property that @ifnottex <> is equivalent to <>. @end ifnottex @@ -83,13 +102,13 @@ the property that $\mit \Gamma(N)\equiv N\times\Gamma(N-1)$. @end tex Accordingly, the results of the gamma function itself grow very -quickly. <> is defined as +quickly. <> is defined as @tex $\mit ln\bigl(\Gamma(x)\bigr)$ rather than simply $\mit \Gamma(x)$ @end tex @ifnottex the natural log of the gamma function, rather than the gamma function -itself, +itself, @end ifnottex to extend the useful range of results representable. @@ -113,8 +132,17 @@ variable <> is not used. These functions may be used for reentrant calls (but they will still set the global variable <> if an error occurs). +<> and <> are the "true gamma" functions, returning +@tex +$\mit \Gamma(x)$, +@end tex +the gamma function of <[x]>--without a logarithm. +(They are apparently so named because of the prior existence of the old, +poorly-named <> functions which returned the log of gamma up +through BSD 4.2.) + RETURNS -Normally, the computed result is returned. +Normally, the computed result is returned. When <[x]> is a nonpositive integer, <> returns <> and <> is set to <>. If the result overflows, <> @@ -123,7 +151,12 @@ returns <> and <> is set to <>. You can modify this error treatment using <>. PORTABILITY -Neither <> nor <> is ANSI C. */ +Neither <> nor <> is ANSI C. It is better not to use either +of these; use <> or <> instead.@* +<>, <>, <>, and <> are nominally C standard +in terms of the base return values, although the <> error-handling +is not standard, nor is the <[signgam]> global for <>. +*/ /* double gamma(double x) * Return the logarithm of the Gamma function of x. -- cgit v1.1