00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
00012
00013 #if defined(LIBM_SCCS) && !defined(lint)
00014 static char rcsid[] = "$NetBSD: e_lgamma_r.c,v 1.7 1995/05/10 20:45:42 jtc Exp $";
00015 #endif
00016
00017
00018
00019
00020
00021
00022
00023
00024
00025
00026
00027
00028
00029
00030
00031
00032
00033
00034
00035
00036
00037
00038
00039
00040
00041
00042
00043
00044
00045
00046
00047
00048
00049
00050
00051
00052
00053
00054
00055
00056
00057
00058
00059
00060
00061
00062
00063
00064
00065
00066
00067
00068
00069
00070
00071
00072
00073
00074
00075
00076
00077
00078
00079
00080
00081
00082
00083
00084 #include "math.h"
00085 #include "mathP.h"
00086
00087 #ifdef __STDC__
00088 static const double
00089 #else
00090 static double
00091 #endif
00092 two52= 4.50359962737049600000e+15,
00093 half= 5.00000000000000000000e-01,
00094 one = 1.00000000000000000000e+00,
00095 pi = 3.14159265358979311600e+00,
00096 a0 = 7.72156649015328655494e-02,
00097 a1 = 3.22467033424113591611e-01,
00098 a2 = 6.73523010531292681824e-02,
00099 a3 = 2.05808084325167332806e-02,
00100 a4 = 7.38555086081402883957e-03,
00101 a5 = 2.89051383673415629091e-03,
00102 a6 = 1.19270763183362067845e-03,
00103 a7 = 5.10069792153511336608e-04,
00104 a8 = 2.20862790713908385557e-04,
00105 a9 = 1.08011567247583939954e-04,
00106 a10 = 2.52144565451257326939e-05,
00107 a11 = 4.48640949618915160150e-05,
00108 tc = 1.46163214496836224576e+00,
00109 tf = -1.21486290535849611461e-01,
00110
00111 tt = -3.63867699703950536541e-18,
00112 t0 = 4.83836122723810047042e-01,
00113 t1 = -1.47587722994593911752e-01,
00114 t2 = 6.46249402391333854778e-02,
00115 t3 = -3.27885410759859649565e-02,
00116 t4 = 1.79706750811820387126e-02,
00117 t5 = -1.03142241298341437450e-02,
00118 t6 = 6.10053870246291332635e-03,
00119 t7 = -3.68452016781138256760e-03,
00120 t8 = 2.25964780900612472250e-03,
00121 t9 = -1.40346469989232843813e-03,
00122 t10 = 8.81081882437654011382e-04,
00123 t11 = -5.38595305356740546715e-04,
00124 t12 = 3.15632070903625950361e-04,
00125 t13 = -3.12754168375120860518e-04,
00126 t14 = 3.35529192635519073543e-04,
00127 u0 = -7.72156649015328655494e-02,
00128 u1 = 6.32827064025093366517e-01,
00129 u2 = 1.45492250137234768737e+00,
00130 u3 = 9.77717527963372745603e-01,
00131 u4 = 2.28963728064692451092e-01,
00132 u5 = 1.33810918536787660377e-02,
00133 v1 = 2.45597793713041134822e+00,
00134 v2 = 2.12848976379893395361e+00,
00135 v3 = 7.69285150456672783825e-01,
00136 v4 = 1.04222645593369134254e-01,
00137 v5 = 3.21709242282423911810e-03,
00138 s0 = -7.72156649015328655494e-02,
00139 s1 = 2.14982415960608852501e-01,
00140 s2 = 3.25778796408930981787e-01,
00141 s3 = 1.46350472652464452805e-01,
00142 s4 = 2.66422703033638609560e-02,
00143 s5 = 1.84028451407337715652e-03,
00144 s6 = 3.19475326584100867617e-05,
00145 r1 = 1.39200533467621045958e+00,
00146 r2 = 7.21935547567138069525e-01,
00147 r3 = 1.71933865632803078993e-01,
00148 r4 = 1.86459191715652901344e-02,
00149 r5 = 7.77942496381893596434e-04,
00150 r6 = 7.32668430744625636189e-06,
00151 w0 = 4.18938533204672725052e-01,
00152 w1 = 8.33333333333329678849e-02,
00153 w2 = -2.77777777728775536470e-03,
00154 w3 = 7.93650558643019558500e-04,
00155 w4 = -5.95187557450339963135e-04,
00156 w5 = 8.36339918996282139126e-04,
00157 w6 = -1.63092934096575273989e-03;
00158
00159 #ifdef __STDC__
00160 static const double zero= 0.00000000000000000000e+00;
00161 #else
00162 static double zero= 0.00000000000000000000e+00;
00163 #endif
00164
00165 static
00166 #ifdef __GNUC__
00167 __inline__
00168 #endif
00169 #ifdef __STDC__
00170 double sin_pi(double x)
00171 #else
00172 double sin_pi(x)
00173 double x;
00174 #endif
00175 {
00176 double y,z;
00177 int n,ix;
00178
00179 GET_HIGH_WORD(ix,x);
00180 ix &= 0x7fffffff;
00181
00182 if(ix<0x3fd00000) return __kernel_sin(pi*x,zero,0);
00183 y = -x;
00184
00185
00186
00187
00188
00189 z = floor(y);
00190 if(z!=y) {
00191 y *= 0.5;
00192 y = 2.0*(y - floor(y));
00193 n = (int) (y*4.0);
00194 } else {
00195 if(ix>=0x43400000) {
00196 y = zero; n = 0;
00197 } else {
00198 if(ix<0x43300000) z = y+two52;
00199 GET_LOW_WORD(n,z);
00200 n &= 1;
00201 y = n;
00202 n<<= 2;
00203 }
00204 }
00205 switch (n) {
00206 case 0: y = __kernel_sin(pi*y,zero,0); break;
00207 case 1:
00208 case 2: y = __kernel_cos(pi*(0.5-y),zero); break;
00209 case 3:
00210 case 4: y = __kernel_sin(pi*(one-y),zero,0); break;
00211 case 5:
00212 case 6: y = -__kernel_cos(pi*(y-1.5),zero); break;
00213 default: y = __kernel_sin(pi*(y-2.0),zero,0); break;
00214 }
00215 return -y;
00216 }
00217
00218
00219 #ifdef __STDC__
00220 double __ieee754_lgamma_r(double x, int *signgamp)
00221 #else
00222 double __ieee754_lgamma_r(x,signgamp)
00223 double x; int *signgamp;
00224 #endif
00225 {
00226 double t,y,z,nadj=0.0,p,p1,p2,p3,q,r,w;
00227 int i,hx,lx,ix;
00228
00229 EXTRACT_WORDS(hx,lx,x);
00230
00231
00232 *signgamp = 1;
00233 ix = hx&0x7fffffff;
00234 if(ix>=0x7ff00000) return x*x;
00235 if((ix|lx)==0) return one/zero;
00236 if(ix<0x3b900000) {
00237 if(hx<0) {
00238 *signgamp = -1;
00239 return -__ieee754_log(-x);
00240 } else return -__ieee754_log(x);
00241 }
00242 if(hx<0) {
00243 if(ix>=0x43300000)
00244 return one/zero;
00245 t = sin_pi(x);
00246 if(t==zero) return one/zero;
00247 nadj = __ieee754_log(pi/fabs(t*x));
00248 if(t<zero) *signgamp = -1;
00249 x = -x;
00250 }
00251
00252
00253 if((((ix-0x3ff00000)|lx)==0)||(((ix-0x40000000)|lx)==0)) r = 0;
00254
00255 else if(ix<0x40000000) {
00256 if(ix<=0x3feccccc) {
00257 r = -__ieee754_log(x);
00258 if(ix>=0x3FE76944) {y = one-x; i= 0;}
00259 else if(ix>=0x3FCDA661) {y= x-(tc-one); i=1;}
00260 else {y = x; i=2;}
00261 } else {
00262 r = zero;
00263 if(ix>=0x3FFBB4C3) {y=2.0-x;i=0;}
00264 else if(ix>=0x3FF3B4C4) {y=x-tc;i=1;}
00265 else {y=x-one;i=2;}
00266 }
00267 switch(i) {
00268 case 0:
00269 z = y*y;
00270 p1 = a0+z*(a2+z*(a4+z*(a6+z*(a8+z*a10))));
00271 p2 = z*(a1+z*(a3+z*(a5+z*(a7+z*(a9+z*a11)))));
00272 p = y*p1+p2;
00273 r += (p-0.5*y); break;
00274 case 1:
00275 z = y*y;
00276 w = z*y;
00277 p1 = t0+w*(t3+w*(t6+w*(t9 +w*t12)));
00278 p2 = t1+w*(t4+w*(t7+w*(t10+w*t13)));
00279 p3 = t2+w*(t5+w*(t8+w*(t11+w*t14)));
00280 p = z*p1-(tt-w*(p2+y*p3));
00281 r += (tf + p); break;
00282 case 2:
00283 p1 = y*(u0+y*(u1+y*(u2+y*(u3+y*(u4+y*u5)))));
00284 p2 = one+y*(v1+y*(v2+y*(v3+y*(v4+y*v5))));
00285 r += (-0.5*y + p1/p2);
00286 }
00287 }
00288 else if(ix<0x40200000) {
00289 i = (int)x;
00290 t = zero;
00291 y = x-(double)i;
00292 p = y*(s0+y*(s1+y*(s2+y*(s3+y*(s4+y*(s5+y*s6))))));
00293 q = one+y*(r1+y*(r2+y*(r3+y*(r4+y*(r5+y*r6)))));
00294 r = half*y+p/q;
00295 z = one;
00296 switch(i) {
00297 case 7: z *= (y+6.0);
00298 case 6: z *= (y+5.0);
00299 case 5: z *= (y+4.0);
00300 case 4: z *= (y+3.0);
00301 case 3: z *= (y+2.0);
00302 r += __ieee754_log(z); break;
00303 }
00304
00305 } else if (ix < 0x43900000) {
00306 t = __ieee754_log(x);
00307 z = one/x;
00308 y = z*z;
00309 w = w0+z*(w1+y*(w2+y*(w3+y*(w4+y*(w5+y*w6)))));
00310 r = (x-half)*(t-one)+w;
00311 } else
00312
00313 r = x*(__ieee754_log(x)-one);
00314 if(hx<0) r = nadj - r;
00315 return r;
00316 }