Annotation of src/lib/libm/src/e_lgammaf_r.c, Revision 1.2
1.1 jtc 1: /* e_lgammaf_r.c -- float version of e_lgamma_r.c.
2: * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3: */
4:
5: /*
6: * ====================================================
7: * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8: *
9: * Developed at SunPro, a Sun Microsystems, Inc. business.
10: * Permission to use, copy, modify, and distribute this
11: * software is freely granted, provided that this notice
12: * is preserved.
13: * ====================================================
14: */
15:
1.2 ! jtc 16: #if defined(LIBM_SCCS) && !defined(lint)
! 17: static char rcsid[] = "$Id: e_lgammaf_r.c,v 1.1 1994/08/10 20:31:09 jtc Exp $";
1.1 jtc 18: #endif
19:
20: #include "math.h"
21: #include "math_private.h"
22:
23: #ifdef __STDC__
24: static const float
25: #else
26: static float
27: #endif
28: two23= 8.3886080000e+06, /* 0x4b000000 */
29: half= 5.0000000000e-01, /* 0x3f000000 */
30: one = 1.0000000000e+00, /* 0x3f800000 */
31: pi = 3.1415927410e+00, /* 0x40490fdb */
32: a0 = 7.7215664089e-02, /* 0x3d9e233f */
33: a1 = 3.2246702909e-01, /* 0x3ea51a66 */
34: a2 = 6.7352302372e-02, /* 0x3d89f001 */
35: a3 = 2.0580807701e-02, /* 0x3ca89915 */
36: a4 = 7.3855509982e-03, /* 0x3bf2027e */
37: a5 = 2.8905137442e-03, /* 0x3b3d6ec6 */
38: a6 = 1.1927076848e-03, /* 0x3a9c54a1 */
39: a7 = 5.1006977446e-04, /* 0x3a05b634 */
40: a8 = 2.2086278477e-04, /* 0x39679767 */
41: a9 = 1.0801156895e-04, /* 0x38e28445 */
42: a10 = 2.5214456400e-05, /* 0x37d383a2 */
43: a11 = 4.4864096708e-05, /* 0x383c2c75 */
44: tc = 1.4616321325e+00, /* 0x3fbb16c3 */
45: tf = -1.2148628384e-01, /* 0xbdf8cdcd */
46: /* tt = -(tail of tf) */
47: tt = 6.6971006518e-09, /* 0x31e61c52 */
48: t0 = 4.8383611441e-01, /* 0x3ef7b95e */
49: t1 = -1.4758771658e-01, /* 0xbe17213c */
50: t2 = 6.4624942839e-02, /* 0x3d845a15 */
51: t3 = -3.2788541168e-02, /* 0xbd064d47 */
52: t4 = 1.7970675603e-02, /* 0x3c93373d */
53: t5 = -1.0314224288e-02, /* 0xbc28fcfe */
54: t6 = 6.1005386524e-03, /* 0x3bc7e707 */
55: t7 = -3.6845202558e-03, /* 0xbb7177fe */
56: t8 = 2.2596477065e-03, /* 0x3b141699 */
57: t9 = -1.4034647029e-03, /* 0xbab7f476 */
58: t10 = 8.8108185446e-04, /* 0x3a66f867 */
59: t11 = -5.3859531181e-04, /* 0xba0d3085 */
60: t12 = 3.1563205994e-04, /* 0x39a57b6b */
61: t13 = -3.1275415677e-04, /* 0xb9a3f927 */
62: t14 = 3.3552918467e-04, /* 0x39afe9f7 */
63: u0 = -7.7215664089e-02, /* 0xbd9e233f */
64: u1 = 6.3282704353e-01, /* 0x3f2200f4 */
65: u2 = 1.4549225569e+00, /* 0x3fba3ae7 */
66: u3 = 9.7771751881e-01, /* 0x3f7a4bb2 */
67: u4 = 2.2896373272e-01, /* 0x3e6a7578 */
68: u5 = 1.3381091878e-02, /* 0x3c5b3c5e */
69: v1 = 2.4559779167e+00, /* 0x401d2ebe */
70: v2 = 2.1284897327e+00, /* 0x4008392d */
71: v3 = 7.6928514242e-01, /* 0x3f44efdf */
72: v4 = 1.0422264785e-01, /* 0x3dd572af */
73: v5 = 3.2170924824e-03, /* 0x3b52d5db */
74: s0 = -7.7215664089e-02, /* 0xbd9e233f */
75: s1 = 2.1498242021e-01, /* 0x3e5c245a */
76: s2 = 3.2577878237e-01, /* 0x3ea6cc7a */
77: s3 = 1.4635047317e-01, /* 0x3e15dce6 */
78: s4 = 2.6642270386e-02, /* 0x3cda40e4 */
79: s5 = 1.8402845599e-03, /* 0x3af135b4 */
80: s6 = 3.1947532989e-05, /* 0x3805ff67 */
81: r1 = 1.3920053244e+00, /* 0x3fb22d3b */
82: r2 = 7.2193557024e-01, /* 0x3f38d0c5 */
83: r3 = 1.7193385959e-01, /* 0x3e300f6e */
84: r4 = 1.8645919859e-02, /* 0x3c98bf54 */
85: r5 = 7.7794247773e-04, /* 0x3a4beed6 */
86: r6 = 7.3266842264e-06, /* 0x36f5d7bd */
87: w0 = 4.1893854737e-01, /* 0x3ed67f1d */
88: w1 = 8.3333335817e-02, /* 0x3daaaaab */
89: w2 = -2.7777778450e-03, /* 0xbb360b61 */
90: w3 = 7.9365057172e-04, /* 0x3a500cfd */
91: w4 = -5.9518753551e-04, /* 0xba1c065c */
92: w5 = 8.3633989561e-04, /* 0x3a5b3dd2 */
93: w6 = -1.6309292987e-03; /* 0xbad5c4e8 */
94:
95: #ifdef __STDC__
96: static const float zero= 0.0000000000e+00;
97: #else
98: static float zero= 0.0000000000e+00;
99: #endif
100:
101: #ifdef __STDC__
102: static float sin_pif(float x)
103: #else
104: static float sin_pif(x)
105: float x;
106: #endif
107: {
108: float y,z;
109: int n,ix;
110:
111: GET_FLOAT_WORD(ix,x);
112: ix &= 0x7fffffff;
113:
114: if(ix<0x3e800000) return __kernel_sinf(pi*x,zero,0);
115: y = -x; /* x is assume negative */
116:
117: /*
118: * argument reduction, make sure inexact flag not raised if input
119: * is an integer
120: */
121: z = floorf(y);
122: if(z!=y) { /* inexact anyway */
123: y *= (float)0.5;
124: y = (float)2.0*(y - floorf(y)); /* y = |x| mod 2.0 */
125: n = (int) (y*(float)4.0);
126: } else {
127: if(ix>=0x4b800000) {
128: y = zero; n = 0; /* y must be even */
129: } else {
130: if(ix<0x4b000000) z = y+two23; /* exact */
131: GET_FLOAT_WORD(n,z);
132: n &= 1;
133: y = n;
134: n<<= 2;
135: }
136: }
137: switch (n) {
138: case 0: y = __kernel_sinf(pi*y,zero,0); break;
139: case 1:
140: case 2: y = __kernel_cosf(pi*((float)0.5-y),zero); break;
141: case 3:
142: case 4: y = __kernel_sinf(pi*(one-y),zero,0); break;
143: case 5:
144: case 6: y = -__kernel_cosf(pi*(y-(float)1.5),zero); break;
145: default: y = __kernel_sinf(pi*(y-(float)2.0),zero,0); break;
146: }
147: return -y;
148: }
149:
150:
151: #ifdef __STDC__
152: float __ieee754_lgammaf_r(float x, int *signgamp)
153: #else
154: float __ieee754_lgammaf_r(x,signgamp)
155: float x; int *signgamp;
156: #endif
157: {
158: float t,y,z,nadj,p,p1,p2,p3,q,r,w;
159: int i,hx,ix;
160:
161: GET_FLOAT_WORD(hx,x);
162:
163: /* purge off +-inf, NaN, +-0, and negative arguments */
164: *signgamp = 1;
165: ix = hx&0x7fffffff;
166: if(ix>=0x7f800000) return x*x;
167: if(ix==0) return one/zero;
168: if(ix<0x1c800000) { /* |x|<2**-70, return -log(|x|) */
169: if(hx<0) {
170: *signgamp = -1;
171: return -__ieee754_logf(-x);
172: } else return -__ieee754_logf(x);
173: }
174: if(hx<0) {
175: if(ix>=0x4b000000) /* |x|>=2**23, must be -integer */
176: return one/zero;
177: t = sin_pif(x);
178: if(t==zero) return one/zero; /* -integer */
179: nadj = __ieee754_logf(pi/fabsf(t*x));
180: if(t<zero) *signgamp = -1;
181: x = -x;
182: }
183:
184: /* purge off 1 and 2 */
185: if (ix==0x3f800000||ix==0x40000000) r = 0;
186: /* for x < 2.0 */
187: else if(ix<0x40000000) {
188: if(ix<=0x3f666666) { /* lgamma(x) = lgamma(x+1)-log(x) */
189: r = -__ieee754_logf(x);
190: if(ix>=0x3f3b4a20) {y = one-x; i= 0;}
191: else if(ix>=0x3e6d3308) {y= x-(tc-one); i=1;}
192: else {y = x; i=2;}
193: } else {
194: r = zero;
195: if(ix>=0x3fdda618) {y=(float)2.0-x;i=0;} /* [1.7316,2] */
196: else if(ix>=0x3F9da620) {y=x-tc;i=1;} /* [1.23,1.73] */
197: else {y=x-one;i=2;}
198: }
199: switch(i) {
200: case 0:
201: z = y*y;
202: p1 = a0+z*(a2+z*(a4+z*(a6+z*(a8+z*a10))));
203: p2 = z*(a1+z*(a3+z*(a5+z*(a7+z*(a9+z*a11)))));
204: p = y*p1+p2;
205: r += (p-(float)0.5*y); break;
206: case 1:
207: z = y*y;
208: w = z*y;
209: p1 = t0+w*(t3+w*(t6+w*(t9 +w*t12))); /* parallel comp */
210: p2 = t1+w*(t4+w*(t7+w*(t10+w*t13)));
211: p3 = t2+w*(t5+w*(t8+w*(t11+w*t14)));
212: p = z*p1-(tt-w*(p2+y*p3));
213: r += (tf + p); break;
214: case 2:
215: p1 = y*(u0+y*(u1+y*(u2+y*(u3+y*(u4+y*u5)))));
216: p2 = one+y*(v1+y*(v2+y*(v3+y*(v4+y*v5))));
217: r += (-(float)0.5*y + p1/p2);
218: }
219: }
220: else if(ix<0x41000000) { /* x < 8.0 */
221: i = (int)x;
222: t = zero;
223: y = x-(float)i;
224: p = y*(s0+y*(s1+y*(s2+y*(s3+y*(s4+y*(s5+y*s6))))));
225: q = one+y*(r1+y*(r2+y*(r3+y*(r4+y*(r5+y*r6)))));
226: r = half*y+p/q;
227: z = one; /* lgamma(1+s) = log(s) + lgamma(s) */
228: switch(i) {
229: case 7: z *= (y+(float)6.0); /* FALLTHRU */
230: case 6: z *= (y+(float)5.0); /* FALLTHRU */
231: case 5: z *= (y+(float)4.0); /* FALLTHRU */
232: case 4: z *= (y+(float)3.0); /* FALLTHRU */
233: case 3: z *= (y+(float)2.0); /* FALLTHRU */
234: r += __ieee754_logf(z); break;
235: }
236: /* 8.0 <= x < 2**58 */
237: } else if (ix < 0x5c800000) {
238: t = __ieee754_logf(x);
239: z = one/x;
240: y = z*z;
241: w = w0+z*(w1+y*(w2+y*(w3+y*(w4+y*(w5+y*w6)))));
242: r = (x-half)*(t-one)+w;
243: } else
244: /* 2**58 <= x <= inf */
245: r = x*(__ieee754_logf(x)-one);
246: if(hx<0) r = nadj - r;
247: return r;
248: }
CVSweb <webmaster@jp.NetBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to e_lgammaf_r.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [cvs.NetBSD.org] / src / lib / libm / src