1 /* e_j1f.c -- float version of e_j1.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
4 * $FreeBSD: src/lib/msun/src/e_j1f.c,v 1.5 1999/08/28 00:06:33 peter Exp $
5 * $DragonFly: src/lib/msun/src/Attic/e_j1f.c,v 1.2 2003/06/17 04:26:52 dillon Exp $
9 * ====================================================
10 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
12 * Developed at SunPro, a Sun Microsystems, Inc. business.
13 * Permission to use, copy, modify, and distribute this
14 * software is freely granted, provided that this notice
16 * ====================================================
20 #include "math_private.h"
23 static float ponef(float), qonef(float);
25 static float ponef(), qonef();
35 invsqrtpi= 5.6418961287e-01, /* 0x3f106ebb */
36 tpi = 6.3661974669e-01, /* 0x3f22f983 */
38 r00 = -6.2500000000e-02, /* 0xbd800000 */
39 r01 = 1.4070566976e-03, /* 0x3ab86cfd */
40 r02 = -1.5995563444e-05, /* 0xb7862e36 */
41 r03 = 4.9672799207e-08, /* 0x335557d2 */
42 s01 = 1.9153760746e-02, /* 0x3c9ce859 */
43 s02 = 1.8594678841e-04, /* 0x3942fab6 */
44 s03 = 1.1771846857e-06, /* 0x359dffc2 */
45 s04 = 5.0463624390e-09, /* 0x31ad6446 */
46 s05 = 1.2354227016e-11; /* 0x2d59567e */
49 static const float zero = 0.0;
51 static float zero = 0.0;
55 float __ieee754_j1f(float x)
57 float __ieee754_j1f(x)
61 float z, s,c,ss,cc,r,u,v,y;
66 if(ix>=0x7f800000) return one/x;
68 if(ix >= 0x40000000) { /* |x| >= 2.0 */
73 if(ix<0x7f000000) { /* make sure y+y not overflow */
75 if ((s*c)>zero) cc = z/ss;
79 * j1(x) = 1/sqrt(pi) * (P(1,x)*cc - Q(1,x)*ss) / sqrt(x)
80 * y1(x) = 1/sqrt(pi) * (P(1,x)*ss + Q(1,x)*cc) / sqrt(x)
82 if(ix>0x80000000) z = (invsqrtpi*cc)/sqrtf(y);
84 u = ponef(y); v = qonef(y);
85 z = invsqrtpi*(u*cc-v*ss)/sqrtf(y);
90 if(ix<0x32000000) { /* |x|<2**-27 */
91 if(huge+x>one) return (float)0.5*x;/* inexact if x!=0 necessary */
94 r = z*(r00+z*(r01+z*(r02+z*r03)));
95 s = one+z*(s01+z*(s02+z*(s03+z*(s04+z*s05))));
97 return(x*(float)0.5+r/s);
101 static const float U0[5] = {
103 static float U0[5] = {
105 -1.9605709612e-01, /* 0xbe48c331 */
106 5.0443872809e-02, /* 0x3d4e9e3c */
107 -1.9125689287e-03, /* 0xbafaaf2a */
108 2.3525259166e-05, /* 0x37c5581c */
109 -9.1909917899e-08, /* 0xb3c56003 */
112 static const float V0[5] = {
114 static float V0[5] = {
116 1.9916731864e-02, /* 0x3ca3286a */
117 2.0255257550e-04, /* 0x3954644b */
118 1.3560879779e-06, /* 0x35b602d4 */
119 6.2274145840e-09, /* 0x31d5f8eb */
120 1.6655924903e-11, /* 0x2d9281cf */
124 float __ieee754_y1f(float x)
126 float __ieee754_y1f(x)
130 float z, s,c,ss,cc,u,v;
133 GET_FLOAT_WORD(hx,x);
135 /* if Y1(NaN) is NaN, Y1(-inf) is NaN, Y1(inf) is 0 */
136 if(ix>=0x7f800000) return one/(x+x*x);
137 if(ix==0) return -one/zero;
138 if(hx<0) return zero/zero;
139 if(ix >= 0x40000000) { /* |x| >= 2.0 */
144 if(ix<0x7f000000) { /* make sure x+x not overflow */
146 if ((s*c)>zero) cc = z/ss;
149 /* y1(x) = sqrt(2/(pi*x))*(p1(x)*sin(x0)+q1(x)*cos(x0))
152 * cos(x0) = cos(x)cos(3pi/4)+sin(x)sin(3pi/4)
153 * = 1/sqrt(2) * (sin(x) - cos(x))
154 * sin(x0) = sin(x)cos(3pi/4)-cos(x)sin(3pi/4)
155 * = -1/sqrt(2) * (cos(x) + sin(x))
156 * To avoid cancellation, use
157 * sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x))
158 * to compute the worse one.
160 if(ix>0x48000000) z = (invsqrtpi*ss)/sqrtf(x);
162 u = ponef(x); v = qonef(x);
163 z = invsqrtpi*(u*ss+v*cc)/sqrtf(x);
167 if(ix<=0x24800000) { /* x < 2**-54 */
171 u = U0[0]+z*(U0[1]+z*(U0[2]+z*(U0[3]+z*U0[4])));
172 v = one+z*(V0[0]+z*(V0[1]+z*(V0[2]+z*(V0[3]+z*V0[4]))));
173 return(x*(u/v) + tpi*(__ieee754_j1f(x)*__ieee754_logf(x)-one/x));
176 /* For x >= 8, the asymptotic expansions of pone is
177 * 1 + 15/128 s^2 - 4725/2^15 s^4 - ..., where s = 1/x.
178 * We approximate pone by
179 * pone(x) = 1 + (R/S)
180 * where R = pr0 + pr1*s^2 + pr2*s^4 + ... + pr5*s^10
181 * S = 1 + ps0*s^2 + ... + ps4*s^10
183 * | pone(x)-1-R/S | <= 2 ** ( -60.06)
187 static const float pr8[6] = { /* for x in [inf, 8]=1/[0,0.125] */
189 static float pr8[6] = { /* for x in [inf, 8]=1/[0,0.125] */
191 0.0000000000e+00, /* 0x00000000 */
192 1.1718750000e-01, /* 0x3df00000 */
193 1.3239480972e+01, /* 0x4153d4ea */
194 4.1205184937e+02, /* 0x43ce06a3 */
195 3.8747453613e+03, /* 0x45722bed */
196 7.9144794922e+03, /* 0x45f753d6 */
199 static const float ps8[5] = {
201 static float ps8[5] = {
203 1.1420736694e+02, /* 0x42e46a2c */
204 3.6509309082e+03, /* 0x45642ee5 */
205 3.6956207031e+04, /* 0x47105c35 */
206 9.7602796875e+04, /* 0x47bea166 */
207 3.0804271484e+04, /* 0x46f0a88b */
211 static const float pr5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */
213 static float pr5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */
215 1.3199052094e-11, /* 0x2d68333f */
216 1.1718749255e-01, /* 0x3defffff */
217 6.8027510643e+00, /* 0x40d9b023 */
218 1.0830818176e+02, /* 0x42d89dca */
219 5.1763616943e+02, /* 0x440168b7 */
220 5.2871520996e+02, /* 0x44042dc6 */
223 static const float ps5[5] = {
225 static float ps5[5] = {
227 5.9280597687e+01, /* 0x426d1f55 */
228 9.9140142822e+02, /* 0x4477d9b1 */
229 5.3532670898e+03, /* 0x45a74a23 */
230 7.8446904297e+03, /* 0x45f52586 */
231 1.5040468750e+03, /* 0x44bc0180 */
235 static const float pr3[6] = {
237 static float pr3[6] = {/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */
239 3.0250391081e-09, /* 0x314fe10d */
240 1.1718686670e-01, /* 0x3defffab */
241 3.9329774380e+00, /* 0x407bb5e7 */
242 3.5119403839e+01, /* 0x420c7a45 */
243 9.1055007935e+01, /* 0x42b61c2a */
244 4.8559066772e+01, /* 0x42423c7c */
247 static const float ps3[5] = {
249 static float ps3[5] = {
251 3.4791309357e+01, /* 0x420b2a4d */
252 3.3676245117e+02, /* 0x43a86198 */
253 1.0468714600e+03, /* 0x4482dbe3 */
254 8.9081134033e+02, /* 0x445eb3ed */
255 1.0378793335e+02, /* 0x42cf936c */
259 static const float pr2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */
261 static float pr2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */
263 1.0771083225e-07, /* 0x33e74ea8 */
264 1.1717621982e-01, /* 0x3deffa16 */
265 2.3685150146e+00, /* 0x401795c0 */
266 1.2242610931e+01, /* 0x4143e1bc */
267 1.7693971634e+01, /* 0x418d8d41 */
268 5.0735230446e+00, /* 0x40a25a4d */
271 static const float ps2[5] = {
273 static float ps2[5] = {
275 2.1436485291e+01, /* 0x41ab7dec */
276 1.2529022980e+02, /* 0x42fa9499 */
277 2.3227647400e+02, /* 0x436846c7 */
278 1.1767937469e+02, /* 0x42eb5bd7 */
279 8.3646392822e+00, /* 0x4105d590 */
283 static float ponef(float x)
285 static float ponef(x)
296 GET_FLOAT_WORD(ix,x);
298 if(ix>=0x41000000) {p = pr8; q= ps8;}
299 else if(ix>=0x40f71c58){p = pr5; q= ps5;}
300 else if(ix>=0x4036db68){p = pr3; q= ps3;}
301 else if(ix>=0x40000000){p = pr2; q= ps2;}
303 r = p[0]+z*(p[1]+z*(p[2]+z*(p[3]+z*(p[4]+z*p[5]))));
304 s = one+z*(q[0]+z*(q[1]+z*(q[2]+z*(q[3]+z*q[4]))));
309 /* For x >= 8, the asymptotic expansions of qone is
310 * 3/8 s - 105/1024 s^3 - ..., where s = 1/x.
311 * We approximate pone by
312 * qone(x) = s*(0.375 + (R/S))
313 * where R = qr1*s^2 + qr2*s^4 + ... + qr5*s^10
314 * S = 1 + qs1*s^2 + ... + qs6*s^12
316 * | qone(x)/s -0.375-R/S | <= 2 ** ( -61.13)
320 static const float qr8[6] = { /* for x in [inf, 8]=1/[0,0.125] */
322 static float qr8[6] = { /* for x in [inf, 8]=1/[0,0.125] */
324 0.0000000000e+00, /* 0x00000000 */
325 -1.0253906250e-01, /* 0xbdd20000 */
326 -1.6271753311e+01, /* 0xc1822c8d */
327 -7.5960174561e+02, /* 0xc43de683 */
328 -1.1849806641e+04, /* 0xc639273a */
329 -4.8438511719e+04, /* 0xc73d3683 */
332 static const float qs8[6] = {
334 static float qs8[6] = {
336 1.6139537048e+02, /* 0x43216537 */
337 7.8253862305e+03, /* 0x45f48b17 */
338 1.3387534375e+05, /* 0x4802bcd6 */
339 7.1965775000e+05, /* 0x492fb29c */
340 6.6660125000e+05, /* 0x4922be94 */
341 -2.9449025000e+05, /* 0xc88fcb48 */
345 static const float qr5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */
347 static float qr5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */
349 -2.0897993405e-11, /* 0xadb7d219 */
350 -1.0253904760e-01, /* 0xbdd1fffe */
351 -8.0564479828e+00, /* 0xc100e736 */
352 -1.8366960144e+02, /* 0xc337ab6b */
353 -1.3731937256e+03, /* 0xc4aba633 */
354 -2.6124443359e+03, /* 0xc523471c */
357 static const float qs5[6] = {
359 static float qs5[6] = {
361 8.1276550293e+01, /* 0x42a28d98 */
362 1.9917987061e+03, /* 0x44f8f98f */
363 1.7468484375e+04, /* 0x468878f8 */
364 4.9851425781e+04, /* 0x4742bb6d */
365 2.7948074219e+04, /* 0x46da5826 */
366 -4.7191835938e+03, /* 0xc5937978 */
370 static const float qr3[6] = {
372 static float qr3[6] = {/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */
374 -5.0783124372e-09, /* 0xb1ae7d4f */
375 -1.0253783315e-01, /* 0xbdd1ff5b */
376 -4.6101160049e+00, /* 0xc0938612 */
377 -5.7847221375e+01, /* 0xc267638e */
378 -2.2824453735e+02, /* 0xc3643e9a */
379 -2.1921012878e+02, /* 0xc35b35cb */
382 static const float qs3[6] = {
384 static float qs3[6] = {
386 4.7665153503e+01, /* 0x423ea91e */
387 6.7386511230e+02, /* 0x4428775e */
388 3.3801528320e+03, /* 0x45534272 */
389 5.5477290039e+03, /* 0x45ad5dd5 */
390 1.9031191406e+03, /* 0x44ede3d0 */
391 -1.3520118713e+02, /* 0xc3073381 */
395 static const float qr2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */
397 static float qr2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */
399 -1.7838172539e-07, /* 0xb43f8932 */
400 -1.0251704603e-01, /* 0xbdd1f475 */
401 -2.7522056103e+00, /* 0xc0302423 */
402 -1.9663616180e+01, /* 0xc19d4f16 */
403 -4.2325313568e+01, /* 0xc2294d1f */
404 -2.1371921539e+01, /* 0xc1aaf9b2 */
407 static const float qs2[6] = {
409 static float qs2[6] = {
411 2.9533363342e+01, /* 0x41ec4454 */
412 2.5298155212e+02, /* 0x437cfb47 */
413 7.5750280762e+02, /* 0x443d602e */
414 7.3939318848e+02, /* 0x4438d92a */
415 1.5594900513e+02, /* 0x431bf2f2 */
416 -4.9594988823e+00, /* 0xc09eb437 */
420 static float qonef(float x)
422 static float qonef(x)
433 GET_FLOAT_WORD(ix,x);
435 if(ix>=0x40200000) {p = qr8; q= qs8;}
436 else if(ix>=0x40f71c58){p = qr5; q= qs5;}
437 else if(ix>=0x4036db68){p = qr3; q= qs3;}
438 else if(ix>=0x40000000){p = qr2; q= qs2;}
440 r = p[0]+z*(p[1]+z*(p[2]+z*(p[3]+z*(p[4]+z*p[5]))));
441 s = one+z*(q[0]+z*(q[1]+z*(q[2]+z*(q[3]+z*(q[4]+z*q[5])))));
442 return ((float).375 + r/s)/x;