added gammal_r and lgammal_r private functions

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27274 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Jérôme Duval 2008-09-01 19:54:55 +00:00
parent 5b3feb866e
commit 0ac2fa30a5
3 changed files with 511 additions and 3 deletions

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/* Implementation of gamma function according to ISO C.
Copyright (C) 1997, 1999, 2001, 2003, 2004 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <math.h>
#include <math_private.h>
long double
__ieee754_gammal_r (long double x, int *signgamp)
{
/* We don't have a real gamma implementation now. We'll use lgamma
and the exp function. But due to the required boundary
conditions we must check some values separately. */
u_int32_t es, hx, lx;
GET_LDOUBLE_WORDS (es, hx, lx, x);
if (((es & 0x7fff) | hx | lx) == 0)
{
/* Return value for x == 0 is Inf with divide by zero exception. */
*signgamp = 0;
return 1.0 / x;
}
if (es == 0xffffffff && ((hx & 0x7fffffff) | lx) == 0)
{
/* x == -Inf. According to ISO this is NaN. */
*signgamp = 0;
return x - x;
}
if ((es & 0x7fff) == 0x7fff && ((hx & 0x7fffffff) | lx) != 0)
{
/* NaN, return it. */
*signgamp = 0;
return x;
}
if ((es & 0x8000) != 0 && x < 0xffffffff && __rintl (x) == x)
{
/* Return value for integer x < 0 is NaN with invalid exception. */
*signgamp = 0;
return (x - x) / (x - x);
}
/* XXX FIXME. */
return __ieee754_expl (__ieee754_lgammal_r (x, signgamp));
}

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/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/* Long double expansions are
Copyright (C) 2001 Stephen L. Moshier <moshier@na-net.ornl.gov>
and are incorporated herein by permission of the author. The author
reserves the right to distribute this material elsewhere under different
copying permissions. These modifications are distributed here under
the following terms:
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* __ieee754_lgammal_r(x, signgamp)
* Reentrant version of the logarithm of the Gamma function
* with user provide pointer for the sign of Gamma(x).
*
* Method:
* 1. Argument Reduction for 0 < x <= 8
* Since gamma(1+s)=s*gamma(s), for x in [0,8], we may
* reduce x to a number in [1.5,2.5] by
* lgamma(1+s) = log(s) + lgamma(s)
* for example,
* lgamma(7.3) = log(6.3) + lgamma(6.3)
* = log(6.3*5.3) + lgamma(5.3)
* = log(6.3*5.3*4.3*3.3*2.3) + lgamma(2.3)
* 2. Polynomial approximation of lgamma around its
* minimun ymin=1.461632144968362245 to maintain monotonicity.
* On [ymin-0.23, ymin+0.27] (i.e., [1.23164,1.73163]), use
* Let z = x-ymin;
* lgamma(x) = -1.214862905358496078218 + z^2*poly(z)
* 2. Rational approximation in the primary interval [2,3]
* We use the following approximation:
* s = x-2.0;
* lgamma(x) = 0.5*s + s*P(s)/Q(s)
* Our algorithms are based on the following observation
*
* zeta(2)-1 2 zeta(3)-1 3
* lgamma(2+s) = s*(1-Euler) + --------- * s - --------- * s + ...
* 2 3
*
* where Euler = 0.5771... is the Euler constant, which is very
* close to 0.5.
*
* 3. For x>=8, we have
* lgamma(x)~(x-0.5)log(x)-x+0.5*log(2pi)+1/(12x)-1/(360x**3)+....
* (better formula:
* lgamma(x)~(x-0.5)*(log(x)-1)-.5*(log(2pi)-1) + ...)
* Let z = 1/x, then we approximation
* f(z) = lgamma(x) - (x-0.5)(log(x)-1)
* by
* 3 5 11
* w = w0 + w1*z + w2*z + w3*z + ... + w6*z
*
* 4. For negative x, since (G is gamma function)
* -x*G(-x)*G(x) = pi/sin(pi*x),
* we have
* G(x) = pi/(sin(pi*x)*(-x)*G(-x))
* since G(-x) is positive, sign(G(x)) = sign(sin(pi*x)) for x<0
* Hence, for x<0, signgam = sign(sin(pi*x)) and
* lgamma(x) = log(|Gamma(x)|)
* = log(pi/(|x*sin(pi*x)|)) - lgamma(-x);
* Note: one should avoid compute pi*(-x) directly in the
* computation of sin(pi*(-x)).
*
* 5. Special Cases
* lgamma(2+s) ~ s*(1-Euler) for tiny s
* lgamma(1)=lgamma(2)=0
* lgamma(x) ~ -log(x) for tiny x
* lgamma(0) = lgamma(inf) = inf
* lgamma(-integer) = +-inf
*
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double
#else
static long double
#endif
half = 0.5L,
one = 1.0L,
pi = 3.14159265358979323846264L,
two63 = 9.223372036854775808e18L,
/* lgam(1+x) = 0.5 x + x a(x)/b(x)
-0.268402099609375 <= x <= 0
peak relative error 6.6e-22 */
a0 = -6.343246574721079391729402781192128239938E2L,
a1 = 1.856560238672465796768677717168371401378E3L,
a2 = 2.404733102163746263689288466865843408429E3L,
a3 = 8.804188795790383497379532868917517596322E2L,
a4 = 1.135361354097447729740103745999661157426E2L,
a5 = 3.766956539107615557608581581190400021285E0L,
b0 = 8.214973713960928795704317259806842490498E3L,
b1 = 1.026343508841367384879065363925870888012E4L,
b2 = 4.553337477045763320522762343132210919277E3L,
b3 = 8.506975785032585797446253359230031874803E2L,
b4 = 6.042447899703295436820744186992189445813E1L,
/* b5 = 1.000000000000000000000000000000000000000E0 */
tc = 1.4616321449683623412626595423257213284682E0L,
tf = -1.2148629053584961146050602565082954242826E-1,/* double precision */
/* tt = (tail of tf), i.e. tf + tt has extended precision. */
tt = 3.3649914684731379602768989080467587736363E-18L,
/* lgam ( 1.4616321449683623412626595423257213284682E0 ) =
-1.2148629053584960809551455717769158215135617312999903886372437313313530E-1 */
/* lgam (x + tc) = tf + tt + x g(x)/h(x)
- 0.230003726999612341262659542325721328468 <= x
<= 0.2699962730003876587373404576742786715318
peak relative error 2.1e-21 */
g0 = 3.645529916721223331888305293534095553827E-18L,
g1 = 5.126654642791082497002594216163574795690E3L,
g2 = 8.828603575854624811911631336122070070327E3L,
g3 = 5.464186426932117031234820886525701595203E3L,
g4 = 1.455427403530884193180776558102868592293E3L,
g5 = 1.541735456969245924860307497029155838446E2L,
g6 = 4.335498275274822298341872707453445815118E0L,
h0 = 1.059584930106085509696730443974495979641E4L,
h1 = 2.147921653490043010629481226937850618860E4L,
h2 = 1.643014770044524804175197151958100656728E4L,
h3 = 5.869021995186925517228323497501767586078E3L,
h4 = 9.764244777714344488787381271643502742293E2L,
h5 = 6.442485441570592541741092969581997002349E1L,
/* h6 = 1.000000000000000000000000000000000000000E0 */
/* lgam (x+1) = -0.5 x + x u(x)/v(x)
-0.100006103515625 <= x <= 0.231639862060546875
peak relative error 1.3e-21 */
u0 = -8.886217500092090678492242071879342025627E1L,
u1 = 6.840109978129177639438792958320783599310E2L,
u2 = 2.042626104514127267855588786511809932433E3L,
u3 = 1.911723903442667422201651063009856064275E3L,
u4 = 7.447065275665887457628865263491667767695E2L,
u5 = 1.132256494121790736268471016493103952637E2L,
u6 = 4.484398885516614191003094714505960972894E0L,
v0 = 1.150830924194461522996462401210374632929E3L,
v1 = 3.399692260848747447377972081399737098610E3L,
v2 = 3.786631705644460255229513563657226008015E3L,
v3 = 1.966450123004478374557778781564114347876E3L,
v4 = 4.741359068914069299837355438370682773122E2L,
v5 = 4.508989649747184050907206782117647852364E1L,
/* v6 = 1.000000000000000000000000000000000000000E0 */
/* lgam (x+2) = .5 x + x s(x)/r(x)
0 <= x <= 1
peak relative error 7.2e-22 */
s0 = 1.454726263410661942989109455292824853344E6L,
s1 = -3.901428390086348447890408306153378922752E6L,
s2 = -6.573568698209374121847873064292963089438E6L,
s3 = -3.319055881485044417245964508099095984643E6L,
s4 = -7.094891568758439227560184618114707107977E5L,
s5 = -6.263426646464505837422314539808112478303E4L,
s6 = -1.684926520999477529949915657519454051529E3L,
r0 = -1.883978160734303518163008696712983134698E7L,
r1 = -2.815206082812062064902202753264922306830E7L,
r2 = -1.600245495251915899081846093343626358398E7L,
r3 = -4.310526301881305003489257052083370058799E6L,
r4 = -5.563807682263923279438235987186184968542E5L,
r5 = -3.027734654434169996032905158145259713083E4L,
r6 = -4.501995652861105629217250715790764371267E2L,
/* r6 = 1.000000000000000000000000000000000000000E0 */
/* lgam(x) = ( x - 0.5 ) * log(x) - x + LS2PI + 1/x w(1/x^2)
x >= 8
Peak relative error 1.51e-21
w0 = LS2PI - 0.5 */
w0 = 4.189385332046727417803e-1L,
w1 = 8.333333333333331447505E-2L,
w2 = -2.777777777750349603440E-3L,
w3 = 7.936507795855070755671E-4L,
w4 = -5.952345851765688514613E-4L,
w5 = 8.412723297322498080632E-4L,
w6 = -1.880801938119376907179E-3L,
w7 = 4.885026142432270781165E-3L;
#ifdef __STDC__
static const long double zero = 0.0L;
#else
static long double zero = 0.0L;
#endif
#ifdef __STDC__
static long double
sin_pi (long double x)
#else
static long double
sin_pi (x)
long double x;
#endif
{
long double y, z;
int n, ix;
u_int32_t se, i0, i1;
GET_LDOUBLE_WORDS (se, i0, i1, x);
ix = se & 0x7fff;
ix = (ix << 16) | (i0 >> 16);
if (ix < 0x3ffd8000) /* 0.25 */
return __sinl (pi * x);
y = -x; /* x is assume negative */
/*
* argument reduction, make sure inexact flag not raised if input
* is an integer
*/
z = __floorl (y);
if (z != y)
{ /* inexact anyway */
y *= 0.5;
y = 2.0*(y - __floorl(y)); /* y = |x| mod 2.0 */
n = (int) (y*4.0);
}
else
{
if (ix >= 0x403f8000) /* 2^64 */
{
y = zero; n = 0; /* y must be even */
}
else
{
if (ix < 0x403e8000) /* 2^63 */
z = y + two63; /* exact */
GET_LDOUBLE_WORDS (se, i0, i1, z);
n = i1 & 1;
y = n;
n <<= 2;
}
}
switch (n)
{
case 0:
y = __sinl (pi * y);
break;
case 1:
case 2:
y = __cosl (pi * (half - y));
break;
case 3:
case 4:
y = __sinl (pi * (one - y));
break;
case 5:
case 6:
y = -__cosl (pi * (y - 1.5));
break;
default:
y = __sinl (pi * (y - 2.0));
break;
}
return -y;
}
#ifdef __STDC__
long double
__ieee754_lgammal_r (long double x, int *signgamp)
#else
long double
__ieee754_lgammal_r (x, signgamp)
long double x;
int *signgamp;
#endif
{
long double t, y, z, nadj, p, p1, p2, q, r, w;
int i, ix;
u_int32_t se, i0, i1;
*signgamp = 1;
GET_LDOUBLE_WORDS (se, i0, i1, x);
ix = se & 0x7fff;
if ((ix | i0 | i1) == 0)
return one / fabsl (x);
ix = (ix << 16) | (i0 >> 16);
/* purge off +-inf, NaN, +-0, and negative arguments */
if (ix >= 0x7fff0000)
return x * x;
if (ix < 0x3fc08000) /* 2^-63 */
{ /* |x|<2**-63, return -log(|x|) */
if (se & 0x8000)
{
*signgamp = -1;
return -__ieee754_logl (-x);
}
else
return -__ieee754_logl (x);
}
if (se & 0x8000)
{
t = sin_pi (x);
if (t == zero)
return one / fabsl (t); /* -integer */
nadj = __ieee754_logl (pi / fabsl (t * x));
if (t < zero)
*signgamp = -1;
x = -x;
}
/* purge off 1 and 2 */
if ((((ix - 0x3fff8000) | i0 | i1) == 0)
|| (((ix - 0x40008000) | i0 | i1) == 0))
r = 0;
else if (ix < 0x40008000) /* 2.0 */
{
/* x < 2.0 */
if (ix <= 0x3ffee666) /* 8.99993896484375e-1 */
{
/* lgamma(x) = lgamma(x+1) - log(x) */
r = -__ieee754_logl (x);
if (ix >= 0x3ffebb4a) /* 7.31597900390625e-1 */
{
y = x - one;
i = 0;
}
else if (ix >= 0x3ffced33)/* 2.31639862060546875e-1 */
{
y = x - (tc - one);
i = 1;
}
else
{
/* x < 0.23 */
y = x;
i = 2;
}
}
else
{
r = zero;
if (ix >= 0x3fffdda6) /* 1.73162841796875 */
{
/* [1.7316,2] */
y = x - 2.0;
i = 0;
}
else if (ix >= 0x3fff9da6)/* 1.23162841796875 */
{
/* [1.23,1.73] */
y = x - tc;
i = 1;
}
else
{
/* [0.9, 1.23] */
y = x - one;
i = 2;
}
}
switch (i)
{
case 0:
p1 = a0 + y * (a1 + y * (a2 + y * (a3 + y * (a4 + y * a5))));
p2 = b0 + y * (b1 + y * (b2 + y * (b3 + y * (b4 + y))));
r += half * y + y * p1/p2;
break;
case 1:
p1 = g0 + y * (g1 + y * (g2 + y * (g3 + y * (g4 + y * (g5 + y * g6)))));
p2 = h0 + y * (h1 + y * (h2 + y * (h3 + y * (h4 + y * (h5 + y)))));
p = tt + y * p1/p2;
r += (tf + p);
break;
case 2:
p1 = y * (u0 + y * (u1 + y * (u2 + y * (u3 + y * (u4 + y * (u5 + y * u6))))));
p2 = v0 + y * (v1 + y * (v2 + y * (v3 + y * (v4 + y * (v5 + y)))));
r += (-half * y + p1 / p2);
}
}
else if (ix < 0x40028000) /* 8.0 */
{
/* x < 8.0 */
i = (int) x;
t = zero;
y = x - (double) i;
p = y *
(s0 + y * (s1 + y * (s2 + y * (s3 + y * (s4 + y * (s5 + y * s6))))));
q = r0 + y * (r1 + y * (r2 + y * (r3 + y * (r4 + y * (r5 + y * (r6 + y))))));
r = half * y + p / q;
z = one; /* lgamma(1+s) = log(s) + lgamma(s) */
switch (i)
{
case 7:
z *= (y + 6.0); /* FALLTHRU */
case 6:
z *= (y + 5.0); /* FALLTHRU */
case 5:
z *= (y + 4.0); /* FALLTHRU */
case 4:
z *= (y + 3.0); /* FALLTHRU */
case 3:
z *= (y + 2.0); /* FALLTHRU */
r += __ieee754_logl (z);
break;
}
}
else if (ix < 0x40418000) /* 2^66 */
{
/* 8.0 <= x < 2**66 */
t = __ieee754_logl (x);
z = one / x;
y = z * z;
w = w0 + z * (w1
+ y * (w2 + y * (w3 + y * (w4 + y * (w5 + y * (w6 + y * w7))))));
r = (x - half) * (t - one) + w;
}
else
/* 2**66 <= x <= inf */
r = x * (__ieee754_logl (x) - one);
if (se & 0x8000)
r = nadj - r;
return r;
}

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@ -26,11 +26,11 @@ local genericSources =
mul.c mul_n.c
e_cosh.c e_coshf.c # e_coshl.c
e_sinh.c e_sinhf.c # e_sinhl.c
e_gamma_r.c e_gammaf_r.c
e_gamma_r.c e_gammaf_r.c e_gammal_r.c
e_j0.c e_j0f.c
e_j1.c e_j1f.c
e_jn.c e_jnf.c
e_lgamma_r.c e_lgammaf_r.c
e_lgamma_r.c e_lgammaf_r.c e_lgammal_r.c
k_cos.c k_cosf.c
k_sin.c k_sinf.c
k_tan.c k_tanf.c
@ -90,7 +90,7 @@ local genericSources =
w_scalb.c w_scalbf.c # w_scalbl.c
w_sinh.c w_sinhf.c # w_sinhl.c
w_sqrt.c w_sqrtf.c # w_sqrtl.c
w_tgamma.c w_tgammaf.c # w_tgammal.c
w_tgamma.c w_tgammaf.c w_tgammal.c
;
MergeObject posix_gnu_arch_$(TARGET_ARCH)_other.o :