12116Sjkh/* e_j0f.c -- float version of e_j0.c. 22116Sjkh * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 32116Sjkh */ 42116Sjkh 52116Sjkh/* 62116Sjkh * ==================================================== 72116Sjkh * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 82116Sjkh * 92116Sjkh * Developed at SunPro, a Sun Microsystems, Inc. business. 102116Sjkh * Permission to use, copy, modify, and distribute this 118870Srgrimes * software is freely granted, provided that this notice 122116Sjkh * is preserved. 132116Sjkh * ==================================================== 142116Sjkh */ 152116Sjkh 16176451Sdas#include <sys/cdefs.h> 17176451Sdas__FBSDID("$FreeBSD$"); 182116Sjkh 192116Sjkh#include "math.h" 202116Sjkh#include "math_private.h" 212116Sjkh 222116Sjkhstatic float pzerof(float), qzerof(float); 232116Sjkh 248870Srgrimesstatic const float 252116Sjkhhuge = 1e30, 262116Sjkhone = 1.0, 272116Sjkhinvsqrtpi= 5.6418961287e-01, /* 0x3f106ebb */ 282116Sjkhtpi = 6.3661974669e-01, /* 0x3f22f983 */ 292116Sjkh /* R0/S0 on [0, 2.00] */ 302116SjkhR02 = 1.5625000000e-02, /* 0x3c800000 */ 312116SjkhR03 = -1.8997929874e-04, /* 0xb947352e */ 322116SjkhR04 = 1.8295404516e-06, /* 0x35f58e88 */ 332116SjkhR05 = -4.6183270541e-09, /* 0xb19eaf3c */ 342116SjkhS01 = 1.5619102865e-02, /* 0x3c7fe744 */ 352116SjkhS02 = 1.1692678527e-04, /* 0x38f53697 */ 362116SjkhS03 = 5.1354652442e-07, /* 0x3509daa6 */ 372116SjkhS04 = 1.1661400734e-09; /* 0x30a045e8 */ 382116Sjkh 392116Sjkhstatic const float zero = 0.0; 402116Sjkh 4197413Salfredfloat 4297413Salfred__ieee754_j0f(float x) 432116Sjkh{ 442116Sjkh float z, s,c,ss,cc,r,u,v; 452116Sjkh int32_t hx,ix; 462116Sjkh 472116Sjkh GET_FLOAT_WORD(hx,x); 482116Sjkh ix = hx&0x7fffffff; 492116Sjkh if(ix>=0x7f800000) return one/(x*x); 502116Sjkh x = fabsf(x); 512116Sjkh if(ix >= 0x40000000) { /* |x| >= 2.0 */ 522116Sjkh s = sinf(x); 532116Sjkh c = cosf(x); 542116Sjkh ss = s-c; 552116Sjkh cc = s+c; 562116Sjkh if(ix<0x7f000000) { /* make sure x+x not overflow */ 572116Sjkh z = -cosf(x+x); 582116Sjkh if ((s*c)<zero) cc = z/ss; 592116Sjkh else ss = z/cc; 602116Sjkh } 612116Sjkh /* 622116Sjkh * j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x) 632116Sjkh * y0(x) = 1/sqrt(pi) * (P(0,x)*ss + Q(0,x)*cc) / sqrt(x) 642116Sjkh */ 652116Sjkh if(ix>0x80000000) z = (invsqrtpi*cc)/sqrtf(x); 662116Sjkh else { 672116Sjkh u = pzerof(x); v = qzerof(x); 682116Sjkh z = invsqrtpi*(u*cc-v*ss)/sqrtf(x); 692116Sjkh } 702116Sjkh return z; 712116Sjkh } 722116Sjkh if(ix<0x39000000) { /* |x| < 2**-13 */ 732116Sjkh if(huge+x>one) { /* raise inexact if x != 0 */ 742116Sjkh if(ix<0x32000000) return one; /* |x|<2**-27 */ 752116Sjkh else return one - (float)0.25*x*x; 762116Sjkh } 772116Sjkh } 782116Sjkh z = x*x; 792116Sjkh r = z*(R02+z*(R03+z*(R04+z*R05))); 802116Sjkh s = one+z*(S01+z*(S02+z*(S03+z*S04))); 812116Sjkh if(ix < 0x3F800000) { /* |x| < 1.00 */ 822116Sjkh return one + z*((float)-0.25+(r/s)); 832116Sjkh } else { 842116Sjkh u = (float)0.5*x; 852116Sjkh return((one+u)*(one-u)+z*(r/s)); 862116Sjkh } 872116Sjkh} 882116Sjkh 892116Sjkhstatic const float 902116Sjkhu00 = -7.3804296553e-02, /* 0xbd9726b5 */ 912116Sjkhu01 = 1.7666645348e-01, /* 0x3e34e80d */ 922116Sjkhu02 = -1.3818567619e-02, /* 0xbc626746 */ 932116Sjkhu03 = 3.4745343146e-04, /* 0x39b62a69 */ 942116Sjkhu04 = -3.8140706238e-06, /* 0xb67ff53c */ 952116Sjkhu05 = 1.9559013964e-08, /* 0x32a802ba */ 962116Sjkhu06 = -3.9820518410e-11, /* 0xae2f21eb */ 972116Sjkhv01 = 1.2730483897e-02, /* 0x3c509385 */ 982116Sjkhv02 = 7.6006865129e-05, /* 0x389f65e0 */ 992116Sjkhv03 = 2.5915085189e-07, /* 0x348b216c */ 1002116Sjkhv04 = 4.4111031494e-10; /* 0x2ff280c2 */ 1012116Sjkh 10297413Salfredfloat 10397413Salfred__ieee754_y0f(float x) 1042116Sjkh{ 1052116Sjkh float z, s,c,ss,cc,u,v; 1062116Sjkh int32_t hx,ix; 1072116Sjkh 1082116Sjkh GET_FLOAT_WORD(hx,x); 1092116Sjkh ix = 0x7fffffff&hx; 1102116Sjkh /* Y0(NaN) is NaN, y0(-inf) is Nan, y0(inf) is 0 */ 1118870Srgrimes if(ix>=0x7f800000) return one/(x+x*x); 1122116Sjkh if(ix==0) return -one/zero; 1132116Sjkh if(hx<0) return zero/zero; 1142116Sjkh if(ix >= 0x40000000) { /* |x| >= 2.0 */ 1152116Sjkh /* y0(x) = sqrt(2/(pi*x))*(p0(x)*sin(x0)+q0(x)*cos(x0)) 1162116Sjkh * where x0 = x-pi/4 1172116Sjkh * Better formula: 1182116Sjkh * cos(x0) = cos(x)cos(pi/4)+sin(x)sin(pi/4) 1192116Sjkh * = 1/sqrt(2) * (sin(x) + cos(x)) 1202116Sjkh * sin(x0) = sin(x)cos(3pi/4)-cos(x)sin(3pi/4) 1212116Sjkh * = 1/sqrt(2) * (sin(x) - cos(x)) 1222116Sjkh * To avoid cancellation, use 1232116Sjkh * sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x)) 1242116Sjkh * to compute the worse one. 1252116Sjkh */ 1262116Sjkh s = sinf(x); 1272116Sjkh c = cosf(x); 1282116Sjkh ss = s-c; 1292116Sjkh cc = s+c; 1302116Sjkh /* 1312116Sjkh * j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x) 1322116Sjkh * y0(x) = 1/sqrt(pi) * (P(0,x)*ss + Q(0,x)*cc) / sqrt(x) 1332116Sjkh */ 1342116Sjkh if(ix<0x7f000000) { /* make sure x+x not overflow */ 1352116Sjkh z = -cosf(x+x); 1362116Sjkh if ((s*c)<zero) cc = z/ss; 1372116Sjkh else ss = z/cc; 1382116Sjkh } 1392116Sjkh if(ix>0x80000000) z = (invsqrtpi*ss)/sqrtf(x); 1402116Sjkh else { 1412116Sjkh u = pzerof(x); v = qzerof(x); 1422116Sjkh z = invsqrtpi*(u*ss+v*cc)/sqrtf(x); 1432116Sjkh } 1442116Sjkh return z; 1452116Sjkh } 1462116Sjkh if(ix<=0x32000000) { /* x < 2**-27 */ 1472116Sjkh return(u00 + tpi*__ieee754_logf(x)); 1482116Sjkh } 1492116Sjkh z = x*x; 1502116Sjkh u = u00+z*(u01+z*(u02+z*(u03+z*(u04+z*(u05+z*u06))))); 1512116Sjkh v = one+z*(v01+z*(v02+z*(v03+z*v04))); 1522116Sjkh return(u/v + tpi*(__ieee754_j0f(x)*__ieee754_logf(x))); 1532116Sjkh} 1542116Sjkh 1552116Sjkh/* The asymptotic expansions of pzero is 1562116Sjkh * 1 - 9/128 s^2 + 11025/98304 s^4 - ..., where s = 1/x. 1572116Sjkh * For x >= 2, We approximate pzero by 1582116Sjkh * pzero(x) = 1 + (R/S) 1592116Sjkh * where R = pR0 + pR1*s^2 + pR2*s^4 + ... + pR5*s^10 1602116Sjkh * S = 1 + pS0*s^2 + ... + pS4*s^10 1612116Sjkh * and 1622116Sjkh * | pzero(x)-1-R/S | <= 2 ** ( -60.26) 1632116Sjkh */ 1642116Sjkhstatic const float pR8[6] = { /* for x in [inf, 8]=1/[0,0.125] */ 1652116Sjkh 0.0000000000e+00, /* 0x00000000 */ 1662116Sjkh -7.0312500000e-02, /* 0xbd900000 */ 1672116Sjkh -8.0816707611e+00, /* 0xc1014e86 */ 1682116Sjkh -2.5706311035e+02, /* 0xc3808814 */ 1692116Sjkh -2.4852163086e+03, /* 0xc51b5376 */ 1702116Sjkh -5.2530439453e+03, /* 0xc5a4285a */ 1712116Sjkh}; 1722116Sjkhstatic const float pS8[5] = { 1732116Sjkh 1.1653436279e+02, /* 0x42e91198 */ 1742116Sjkh 3.8337448730e+03, /* 0x456f9beb */ 1752116Sjkh 4.0597855469e+04, /* 0x471e95db */ 1762116Sjkh 1.1675296875e+05, /* 0x47e4087c */ 1772116Sjkh 4.7627726562e+04, /* 0x473a0bba */ 1782116Sjkh}; 1792116Sjkhstatic const float pR5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */ 1802116Sjkh -1.1412546255e-11, /* 0xad48c58a */ 1812116Sjkh -7.0312492549e-02, /* 0xbd8fffff */ 1822116Sjkh -4.1596107483e+00, /* 0xc0851b88 */ 1832116Sjkh -6.7674766541e+01, /* 0xc287597b */ 1842116Sjkh -3.3123129272e+02, /* 0xc3a59d9b */ 1852116Sjkh -3.4643338013e+02, /* 0xc3ad3779 */ 1862116Sjkh}; 1872116Sjkhstatic const float pS5[5] = { 1882116Sjkh 6.0753936768e+01, /* 0x42730408 */ 1892116Sjkh 1.0512523193e+03, /* 0x44836813 */ 1902116Sjkh 5.9789707031e+03, /* 0x45bad7c4 */ 1912116Sjkh 9.6254453125e+03, /* 0x461665c8 */ 1922116Sjkh 2.4060581055e+03, /* 0x451660ee */ 1932116Sjkh}; 1942116Sjkh 1952116Sjkhstatic const float pR3[6] = {/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */ 1962116Sjkh -2.5470459075e-09, /* 0xb12f081b */ 1972116Sjkh -7.0311963558e-02, /* 0xbd8fffb8 */ 1982116Sjkh -2.4090321064e+00, /* 0xc01a2d95 */ 1992116Sjkh -2.1965976715e+01, /* 0xc1afba52 */ 2002116Sjkh -5.8079170227e+01, /* 0xc2685112 */ 2012116Sjkh -3.1447946548e+01, /* 0xc1fb9565 */ 2022116Sjkh}; 2032116Sjkhstatic const float pS3[5] = { 2042116Sjkh 3.5856033325e+01, /* 0x420f6c94 */ 2052116Sjkh 3.6151397705e+02, /* 0x43b4c1ca */ 2062116Sjkh 1.1936077881e+03, /* 0x44953373 */ 2072116Sjkh 1.1279968262e+03, /* 0x448cffe6 */ 2082116Sjkh 1.7358093262e+02, /* 0x432d94b8 */ 2092116Sjkh}; 2102116Sjkh 2112116Sjkhstatic const float pR2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */ 2122116Sjkh -8.8753431271e-08, /* 0xb3be98b7 */ 2132116Sjkh -7.0303097367e-02, /* 0xbd8ffb12 */ 2142116Sjkh -1.4507384300e+00, /* 0xbfb9b1cc */ 2152116Sjkh -7.6356959343e+00, /* 0xc0f4579f */ 2162116Sjkh -1.1193166733e+01, /* 0xc1331736 */ 2172116Sjkh -3.2336456776e+00, /* 0xc04ef40d */ 2182116Sjkh}; 2192116Sjkhstatic const float pS2[5] = { 2202116Sjkh 2.2220300674e+01, /* 0x41b1c32d */ 2212116Sjkh 1.3620678711e+02, /* 0x430834f0 */ 2222116Sjkh 2.7047027588e+02, /* 0x43873c32 */ 2232116Sjkh 1.5387539673e+02, /* 0x4319e01a */ 2242116Sjkh 1.4657617569e+01, /* 0x416a859a */ 2252116Sjkh}; 2262116Sjkh 2272116Sjkh static float pzerof(float x) 2282116Sjkh{ 2292116Sjkh const float *p,*q; 2302116Sjkh float z,r,s; 2312116Sjkh int32_t ix; 2322116Sjkh GET_FLOAT_WORD(ix,x); 2332116Sjkh ix &= 0x7fffffff; 2342116Sjkh if(ix>=0x41000000) {p = pR8; q= pS8;} 2352116Sjkh else if(ix>=0x40f71c58){p = pR5; q= pS5;} 2362116Sjkh else if(ix>=0x4036db68){p = pR3; q= pS3;} 2372116Sjkh else if(ix>=0x40000000){p = pR2; q= pS2;} 2382116Sjkh z = one/(x*x); 2392116Sjkh r = p[0]+z*(p[1]+z*(p[2]+z*(p[3]+z*(p[4]+z*p[5])))); 2402116Sjkh s = one+z*(q[0]+z*(q[1]+z*(q[2]+z*(q[3]+z*q[4])))); 2412116Sjkh return one+ r/s; 2422116Sjkh} 2432116Sjkh 2448870Srgrimes 2452116Sjkh/* For x >= 8, the asymptotic expansions of qzero is 2462116Sjkh * -1/8 s + 75/1024 s^3 - ..., where s = 1/x. 2472116Sjkh * We approximate pzero by 2482116Sjkh * qzero(x) = s*(-1.25 + (R/S)) 2492116Sjkh * where R = qR0 + qR1*s^2 + qR2*s^4 + ... + qR5*s^10 2502116Sjkh * S = 1 + qS0*s^2 + ... + qS5*s^12 2512116Sjkh * and 2522116Sjkh * | qzero(x)/s +1.25-R/S | <= 2 ** ( -61.22) 2532116Sjkh */ 2542116Sjkhstatic const float qR8[6] = { /* for x in [inf, 8]=1/[0,0.125] */ 2552116Sjkh 0.0000000000e+00, /* 0x00000000 */ 2562116Sjkh 7.3242187500e-02, /* 0x3d960000 */ 2572116Sjkh 1.1768206596e+01, /* 0x413c4a93 */ 2582116Sjkh 5.5767340088e+02, /* 0x440b6b19 */ 2592116Sjkh 8.8591972656e+03, /* 0x460a6cca */ 2602116Sjkh 3.7014625000e+04, /* 0x471096a0 */ 2612116Sjkh}; 2622116Sjkhstatic const float qS8[6] = { 2632116Sjkh 1.6377603149e+02, /* 0x4323c6aa */ 2642116Sjkh 8.0983447266e+03, /* 0x45fd12c2 */ 2652116Sjkh 1.4253829688e+05, /* 0x480b3293 */ 2662116Sjkh 8.0330925000e+05, /* 0x49441ed4 */ 2672116Sjkh 8.4050156250e+05, /* 0x494d3359 */ 2682116Sjkh -3.4389928125e+05, /* 0xc8a7eb69 */ 2692116Sjkh}; 2702116Sjkh 2712116Sjkhstatic const float qR5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */ 2722116Sjkh 1.8408595828e-11, /* 0x2da1ec79 */ 2732116Sjkh 7.3242180049e-02, /* 0x3d95ffff */ 2742116Sjkh 5.8356351852e+00, /* 0x40babd86 */ 2752116Sjkh 1.3511157227e+02, /* 0x43071c90 */ 2762116Sjkh 1.0272437744e+03, /* 0x448067cd */ 2772116Sjkh 1.9899779053e+03, /* 0x44f8bf4b */ 2782116Sjkh}; 2792116Sjkhstatic const float qS5[6] = { 2802116Sjkh 8.2776611328e+01, /* 0x42a58da0 */ 2812116Sjkh 2.0778142090e+03, /* 0x4501dd07 */ 2822116Sjkh 1.8847289062e+04, /* 0x46933e94 */ 2832116Sjkh 5.6751113281e+04, /* 0x475daf1d */ 2842116Sjkh 3.5976753906e+04, /* 0x470c88c1 */ 2852116Sjkh -5.3543427734e+03, /* 0xc5a752be */ 2862116Sjkh}; 2872116Sjkh 2882116Sjkhstatic const float qR3[6] = {/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */ 2892116Sjkh 4.3774099900e-09, /* 0x3196681b */ 2902116Sjkh 7.3241114616e-02, /* 0x3d95ff70 */ 2912116Sjkh 3.3442313671e+00, /* 0x405607e3 */ 2922116Sjkh 4.2621845245e+01, /* 0x422a7cc5 */ 2932116Sjkh 1.7080809021e+02, /* 0x432acedf */ 2942116Sjkh 1.6673394775e+02, /* 0x4326bbe4 */ 2952116Sjkh}; 2962116Sjkhstatic const float qS3[6] = { 2972116Sjkh 4.8758872986e+01, /* 0x42430916 */ 2982116Sjkh 7.0968920898e+02, /* 0x44316c1c */ 2992116Sjkh 3.7041481934e+03, /* 0x4567825f */ 3002116Sjkh 6.4604252930e+03, /* 0x45c9e367 */ 3012116Sjkh 2.5163337402e+03, /* 0x451d4557 */ 3022116Sjkh -1.4924745178e+02, /* 0xc3153f59 */ 3032116Sjkh}; 3042116Sjkh 3052116Sjkhstatic const float qR2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */ 3062116Sjkh 1.5044444979e-07, /* 0x342189db */ 3072116Sjkh 7.3223426938e-02, /* 0x3d95f62a */ 3082116Sjkh 1.9981917143e+00, /* 0x3fffc4bf */ 3092116Sjkh 1.4495602608e+01, /* 0x4167edfd */ 3102116Sjkh 3.1666231155e+01, /* 0x41fd5471 */ 3112116Sjkh 1.6252708435e+01, /* 0x4182058c */ 3122116Sjkh}; 3132116Sjkhstatic const float qS2[6] = { 3142116Sjkh 3.0365585327e+01, /* 0x41f2ecb8 */ 3152116Sjkh 2.6934811401e+02, /* 0x4386ac8f */ 3162116Sjkh 8.4478375244e+02, /* 0x44533229 */ 3172116Sjkh 8.8293585205e+02, /* 0x445cbbe5 */ 3182116Sjkh 2.1266638184e+02, /* 0x4354aa98 */ 3192116Sjkh -5.3109550476e+00, /* 0xc0a9f358 */ 3202116Sjkh}; 3212116Sjkh 3222116Sjkh static float qzerof(float x) 3232116Sjkh{ 3242116Sjkh const float *p,*q; 3252116Sjkh float s,r,z; 3262116Sjkh int32_t ix; 3272116Sjkh GET_FLOAT_WORD(ix,x); 3282116Sjkh ix &= 0x7fffffff; 3292116Sjkh if(ix>=0x41000000) {p = qR8; q= qS8;} 3302116Sjkh else if(ix>=0x40f71c58){p = qR5; q= qS5;} 3312116Sjkh else if(ix>=0x4036db68){p = qR3; q= qS3;} 3322116Sjkh else if(ix>=0x40000000){p = qR2; q= qS2;} 3332116Sjkh z = one/(x*x); 3342116Sjkh r = p[0]+z*(p[1]+z*(p[2]+z*(p[3]+z*(p[4]+z*p[5])))); 3352116Sjkh s = one+z*(q[0]+z*(q[1]+z*(q[2]+z*(q[3]+z*(q[4]+z*q[5]))))); 3362116Sjkh return (-(float).125 + r/s)/x; 3372116Sjkh} 338