1/* 2 * Copyright (c) 2014 Advanced Micro Devices, Inc. 3 * Copyright (c) 2016 Aaron Watry <awatry@gmail.com> 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a copy 6 * of this software and associated documentation files (the "Software"), to deal 7 * in the Software without restriction, including without limitation the rights 8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 * copies of the Software, and to permit persons to whom the Software is 10 * furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice shall be included in 13 * all copies or substantial portions of the Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 21 * THE SOFTWARE. 22 */ 23 24#include <clc/clc.h> 25 26#include "../clcmacro.h" 27#include "math.h" 28 29/* 30 * ==================================================== 31 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 32 * 33 * Developed at SunPro, a Sun Microsystems, Inc. business. 34 * Permission to use, copy, modify, and distribute this 35 * software is freely granted, provided that this notice 36 * is preserved. 37 * ==================================================== 38 */ 39 40#define pi_f 3.1415927410e+00f /* 0x40490fdb */ 41 42#define a0_f 7.7215664089e-02f /* 0x3d9e233f */ 43#define a1_f 3.2246702909e-01f /* 0x3ea51a66 */ 44#define a2_f 6.7352302372e-02f /* 0x3d89f001 */ 45#define a3_f 2.0580807701e-02f /* 0x3ca89915 */ 46#define a4_f 7.3855509982e-03f /* 0x3bf2027e */ 47#define a5_f 2.8905137442e-03f /* 0x3b3d6ec6 */ 48#define a6_f 1.1927076848e-03f /* 0x3a9c54a1 */ 49#define a7_f 5.1006977446e-04f /* 0x3a05b634 */ 50#define a8_f 2.2086278477e-04f /* 0x39679767 */ 51#define a9_f 1.0801156895e-04f /* 0x38e28445 */ 52#define a10_f 2.5214456400e-05f /* 0x37d383a2 */ 53#define a11_f 4.4864096708e-05f /* 0x383c2c75 */ 54 55#define tc_f 1.4616321325e+00f /* 0x3fbb16c3 */ 56 57#define tf_f -1.2148628384e-01f /* 0xbdf8cdcd */ 58/* tt -(tail of tf) */ 59#define tt_f 6.6971006518e-09f /* 0x31e61c52 */ 60 61#define t0_f 4.8383611441e-01f /* 0x3ef7b95e */ 62#define t1_f -1.4758771658e-01f /* 0xbe17213c */ 63#define t2_f 6.4624942839e-02f /* 0x3d845a15 */ 64#define t3_f -3.2788541168e-02f /* 0xbd064d47 */ 65#define t4_f 1.7970675603e-02f /* 0x3c93373d */ 66#define t5_f -1.0314224288e-02f /* 0xbc28fcfe */ 67#define t6_f 6.1005386524e-03f /* 0x3bc7e707 */ 68#define t7_f -3.6845202558e-03f /* 0xbb7177fe */ 69#define t8_f 2.2596477065e-03f /* 0x3b141699 */ 70#define t9_f -1.4034647029e-03f /* 0xbab7f476 */ 71#define t10_f 8.8108185446e-04f /* 0x3a66f867 */ 72#define t11_f -5.3859531181e-04f /* 0xba0d3085 */ 73#define t12_f 3.1563205994e-04f /* 0x39a57b6b */ 74#define t13_f -3.1275415677e-04f /* 0xb9a3f927 */ 75#define t14_f 3.3552918467e-04f /* 0x39afe9f7 */ 76 77#define u0_f -7.7215664089e-02f /* 0xbd9e233f */ 78#define u1_f 6.3282704353e-01f /* 0x3f2200f4 */ 79#define u2_f 1.4549225569e+00f /* 0x3fba3ae7 */ 80#define u3_f 9.7771751881e-01f /* 0x3f7a4bb2 */ 81#define u4_f 2.2896373272e-01f /* 0x3e6a7578 */ 82#define u5_f 1.3381091878e-02f /* 0x3c5b3c5e */ 83 84#define v1_f 2.4559779167e+00f /* 0x401d2ebe */ 85#define v2_f 2.1284897327e+00f /* 0x4008392d */ 86#define v3_f 7.6928514242e-01f /* 0x3f44efdf */ 87#define v4_f 1.0422264785e-01f /* 0x3dd572af */ 88#define v5_f 3.2170924824e-03f /* 0x3b52d5db */ 89 90#define s0_f -7.7215664089e-02f /* 0xbd9e233f */ 91#define s1_f 2.1498242021e-01f /* 0x3e5c245a */ 92#define s2_f 3.2577878237e-01f /* 0x3ea6cc7a */ 93#define s3_f 1.4635047317e-01f /* 0x3e15dce6 */ 94#define s4_f 2.6642270386e-02f /* 0x3cda40e4 */ 95#define s5_f 1.8402845599e-03f /* 0x3af135b4 */ 96#define s6_f 3.1947532989e-05f /* 0x3805ff67 */ 97 98#define r1_f 1.3920053244e+00f /* 0x3fb22d3b */ 99#define r2_f 7.2193557024e-01f /* 0x3f38d0c5 */ 100#define r3_f 1.7193385959e-01f /* 0x3e300f6e */ 101#define r4_f 1.8645919859e-02f /* 0x3c98bf54 */ 102#define r5_f 7.7794247773e-04f /* 0x3a4beed6 */ 103#define r6_f 7.3266842264e-06f /* 0x36f5d7bd */ 104 105#define w0_f 4.1893854737e-01f /* 0x3ed67f1d */ 106#define w1_f 8.3333335817e-02f /* 0x3daaaaab */ 107#define w2_f -2.7777778450e-03f /* 0xbb360b61 */ 108#define w3_f 7.9365057172e-04f /* 0x3a500cfd */ 109#define w4_f -5.9518753551e-04f /* 0xba1c065c */ 110#define w5_f 8.3633989561e-04f /* 0x3a5b3dd2 */ 111#define w6_f -1.6309292987e-03f /* 0xbad5c4e8 */ 112 113_CLC_OVERLOAD _CLC_DEF float lgamma_r(float x, private int *signp) { 114 int hx = as_int(x); 115 int ix = hx & 0x7fffffff; 116 float absx = as_float(ix); 117 118 if (ix >= 0x7f800000) { 119 *signp = 1; 120 return x; 121 } 122 123 if (absx < 0x1.0p-70f) { 124 *signp = hx < 0 ? -1 : 1; 125 return -log(absx); 126 } 127 128 float r; 129 130 if (absx == 1.0f | absx == 2.0f) 131 r = 0.0f; 132 133 else if (absx < 2.0f) { 134 float y = 2.0f - absx; 135 int i = 0; 136 137 int c = absx < 0x1.bb4c30p+0f; 138 float yt = absx - tc_f; 139 y = c ? yt : y; 140 i = c ? 1 : i; 141 142 c = absx < 0x1.3b4c40p+0f; 143 yt = absx - 1.0f; 144 y = c ? yt : y; 145 i = c ? 2 : i; 146 147 r = -log(absx); 148 yt = 1.0f - absx; 149 c = absx <= 0x1.ccccccp-1f; 150 r = c ? r : 0.0f; 151 y = c ? yt : y; 152 i = c ? 0 : i; 153 154 c = absx < 0x1.769440p-1f; 155 yt = absx - (tc_f - 1.0f); 156 y = c ? yt : y; 157 i = c ? 1 : i; 158 159 c = absx < 0x1.da6610p-3f; 160 y = c ? absx : y; 161 i = c ? 2 : i; 162 163 float z, w, p1, p2, p3, p; 164 switch (i) { 165 case 0: 166 z = y * y; 167 p1 = mad(z, mad(z, mad(z, mad(z, mad(z, a10_f, a8_f), a6_f), a4_f), a2_f), a0_f); 168 p2 = z * mad(z, mad(z, mad(z, mad(z, mad(z, a11_f, a9_f), a7_f), a5_f), a3_f), a1_f); 169 p = mad(y, p1, p2); 170 r += mad(y, -0.5f, p); 171 break; 172 case 1: 173 z = y * y; 174 w = z * y; 175 p1 = mad(w, mad(w, mad(w, mad(w, t12_f, t9_f), t6_f), t3_f), t0_f); 176 p2 = mad(w, mad(w, mad(w, mad(w, t13_f, t10_f), t7_f), t4_f), t1_f); 177 p3 = mad(w, mad(w, mad(w, mad(w, t14_f, t11_f), t8_f), t5_f), t2_f); 178 p = mad(z, p1, -mad(w, -mad(y, p3, p2), tt_f)); 179 r += tf_f + p; 180 break; 181 case 2: 182 p1 = y * mad(y, mad(y, mad(y, mad(y, mad(y, u5_f, u4_f), u3_f), u2_f), u1_f), u0_f); 183 p2 = mad(y, mad(y, mad(y, mad(y, mad(y, v5_f, v4_f), v3_f), v2_f), v1_f), 1.0f); 184 r += mad(y, -0.5f, MATH_DIVIDE(p1, p2)); 185 break; 186 } 187 } else if (absx < 8.0f) { 188 int i = (int) absx; 189 float y = absx - (float) i; 190 float p = y * mad(y, mad(y, mad(y, mad(y, mad(y, mad(y, s6_f, s5_f), s4_f), s3_f), s2_f), s1_f), s0_f); 191 float q = mad(y, mad(y, mad(y, mad(y, mad(y, mad(y, r6_f, r5_f), r4_f), r3_f), r2_f), r1_f), 1.0f); 192 r = mad(y, 0.5f, MATH_DIVIDE(p, q)); 193 194 float y6 = y + 6.0f; 195 float y5 = y + 5.0f; 196 float y4 = y + 4.0f; 197 float y3 = y + 3.0f; 198 float y2 = y + 2.0f; 199 200 float z = 1.0f; 201 z *= i > 6 ? y6 : 1.0f; 202 z *= i > 5 ? y5 : 1.0f; 203 z *= i > 4 ? y4 : 1.0f; 204 z *= i > 3 ? y3 : 1.0f; 205 z *= i > 2 ? y2 : 1.0f; 206 207 r += log(z); 208 } else if (absx < 0x1.0p+58f) { 209 float z = 1.0f / absx; 210 float y = z * z; 211 float w = mad(z, mad(y, mad(y, mad(y, mad(y, mad(y, w6_f, w5_f), w4_f), w3_f), w2_f), w1_f), w0_f); 212 r = mad(absx - 0.5f, log(absx) - 1.0f, w); 213 } else 214 // 2**58 <= x <= Inf 215 r = absx * (log(absx) - 1.0f); 216 217 int s = 1; 218 219 if (x < 0.0f) { 220 float t = sinpi(x); 221 r = log(pi_f / fabs(t * x)) - r; 222 r = t == 0.0f ? as_float(PINFBITPATT_SP32) : r; 223 s = t < 0.0f ? -1 : s; 224 } 225 226 *signp = s; 227 return r; 228} 229 230_CLC_V_V_VP_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, lgamma_r, float, private, int) 231 232#ifdef cl_khr_fp64 233#pragma OPENCL EXTENSION cl_khr_fp64 : enable 234// ==================================================== 235// Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 236// 237// Developed at SunPro, a Sun Microsystems, Inc. business. 238// Permission to use, copy, modify, and distribute this 239// software is freely granted, provided that this notice 240// is preserved. 241// ==================================================== 242 243// lgamma_r(x, i) 244// Reentrant version of the logarithm of the Gamma function 245// with user provide pointer for the sign of Gamma(x). 246// 247// Method: 248// 1. Argument Reduction for 0 < x <= 8 249// Since gamma(1+s)=s*gamma(s), for x in [0,8], we may 250// reduce x to a number in [1.5,2.5] by 251// lgamma(1+s) = log(s) + lgamma(s) 252// for example, 253// lgamma(7.3) = log(6.3) + lgamma(6.3) 254// = log(6.3*5.3) + lgamma(5.3) 255// = log(6.3*5.3*4.3*3.3*2.3) + lgamma(2.3) 256// 2. Polynomial approximation of lgamma around its 257// minimun ymin=1.461632144968362245 to maintain monotonicity. 258// On [ymin-0.23, ymin+0.27] (i.e., [1.23164,1.73163]), use 259// Let z = x-ymin; 260// lgamma(x) = -1.214862905358496078218 + z^2*poly(z) 261// where 262// poly(z) is a 14 degree polynomial. 263// 2. Rational approximation in the primary interval [2,3] 264// We use the following approximation: 265// s = x-2.0; 266// lgamma(x) = 0.5*s + s*P(s)/Q(s) 267// with accuracy 268// |P/Q - (lgamma(x)-0.5s)| < 2**-61.71 269// Our algorithms are based on the following observation 270// 271// zeta(2)-1 2 zeta(3)-1 3 272// lgamma(2+s) = s*(1-Euler) + --------- * s - --------- * s + ... 273// 2 3 274// 275// where Euler = 0.5771... is the Euler constant, which is very 276// close to 0.5. 277// 278// 3. For x>=8, we have 279// lgamma(x)~(x-0.5)log(x)-x+0.5*log(2pi)+1/(12x)-1/(360x**3)+.... 280// (better formula: 281// lgamma(x)~(x-0.5)*(log(x)-1)-.5*(log(2pi)-1) + ...) 282// Let z = 1/x, then we approximation 283// f(z) = lgamma(x) - (x-0.5)(log(x)-1) 284// by 285// 3 5 11 286// w = w0 + w1*z + w2*z + w3*z + ... + w6*z 287// where 288// |w - f(z)| < 2**-58.74 289// 290// 4. For negative x, since (G is gamma function) 291// -x*G(-x)*G(x) = pi/sin(pi*x), 292// we have 293// G(x) = pi/(sin(pi*x)*(-x)*G(-x)) 294// since G(-x) is positive, sign(G(x)) = sign(sin(pi*x)) for x<0 295// Hence, for x<0, signgam = sign(sin(pi*x)) and 296// lgamma(x) = log(|Gamma(x)|) 297// = log(pi/(|x*sin(pi*x)|)) - lgamma(-x); 298// Note: one should avoid compute pi*(-x) directly in the 299// computation of sin(pi*(-x)). 300// 301// 5. Special Cases 302// lgamma(2+s) ~ s*(1-Euler) for tiny s 303// lgamma(1)=lgamma(2)=0 304// lgamma(x) ~ -log(x) for tiny x 305// lgamma(0) = lgamma(inf) = inf 306// lgamma(-integer) = +-inf 307// 308#define pi 3.14159265358979311600e+00 /* 0x400921FB, 0x54442D18 */ 309 310#define a0 7.72156649015328655494e-02 /* 0x3FB3C467, 0xE37DB0C8 */ 311#define a1 3.22467033424113591611e-01 /* 0x3FD4A34C, 0xC4A60FAD */ 312#define a2 6.73523010531292681824e-02 /* 0x3FB13E00, 0x1A5562A7 */ 313#define a3 2.05808084325167332806e-02 /* 0x3F951322, 0xAC92547B */ 314#define a4 7.38555086081402883957e-03 /* 0x3F7E404F, 0xB68FEFE8 */ 315#define a5 2.89051383673415629091e-03 /* 0x3F67ADD8, 0xCCB7926B */ 316#define a6 1.19270763183362067845e-03 /* 0x3F538A94, 0x116F3F5D */ 317#define a7 5.10069792153511336608e-04 /* 0x3F40B6C6, 0x89B99C00 */ 318#define a8 2.20862790713908385557e-04 /* 0x3F2CF2EC, 0xED10E54D */ 319#define a9 1.08011567247583939954e-04 /* 0x3F1C5088, 0x987DFB07 */ 320#define a10 2.52144565451257326939e-05 /* 0x3EFA7074, 0x428CFA52 */ 321#define a11 4.48640949618915160150e-05 /* 0x3F07858E, 0x90A45837 */ 322 323#define tc 1.46163214496836224576e+00 /* 0x3FF762D8, 0x6356BE3F */ 324#define tf -1.21486290535849611461e-01 /* 0xBFBF19B9, 0xBCC38A42 */ 325#define tt -3.63867699703950536541e-18 /* 0xBC50C7CA, 0xA48A971F */ 326 327#define t0 4.83836122723810047042e-01 /* 0x3FDEF72B, 0xC8EE38A2 */ 328#define t1 -1.47587722994593911752e-01 /* 0xBFC2E427, 0x8DC6C509 */ 329#define t2 6.46249402391333854778e-02 /* 0x3FB08B42, 0x94D5419B */ 330#define t3 -3.27885410759859649565e-02 /* 0xBFA0C9A8, 0xDF35B713 */ 331#define t4 1.79706750811820387126e-02 /* 0x3F9266E7, 0x970AF9EC */ 332#define t5 -1.03142241298341437450e-02 /* 0xBF851F9F, 0xBA91EC6A */ 333#define t6 6.10053870246291332635e-03 /* 0x3F78FCE0, 0xE370E344 */ 334#define t7 -3.68452016781138256760e-03 /* 0xBF6E2EFF, 0xB3E914D7 */ 335#define t8 2.25964780900612472250e-03 /* 0x3F6282D3, 0x2E15C915 */ 336#define t9 -1.40346469989232843813e-03 /* 0xBF56FE8E, 0xBF2D1AF1 */ 337#define t10 8.81081882437654011382e-04 /* 0x3F4CDF0C, 0xEF61A8E9 */ 338#define t11 -5.38595305356740546715e-04 /* 0xBF41A610, 0x9C73E0EC */ 339#define t12 3.15632070903625950361e-04 /* 0x3F34AF6D, 0x6C0EBBF7 */ 340#define t13 -3.12754168375120860518e-04 /* 0xBF347F24, 0xECC38C38 */ 341#define t14 3.35529192635519073543e-04 /* 0x3F35FD3E, 0xE8C2D3F4 */ 342 343#define u0 -7.72156649015328655494e-02 /* 0xBFB3C467, 0xE37DB0C8 */ 344#define u1 6.32827064025093366517e-01 /* 0x3FE4401E, 0x8B005DFF */ 345#define u2 1.45492250137234768737e+00 /* 0x3FF7475C, 0xD119BD6F */ 346#define u3 9.77717527963372745603e-01 /* 0x3FEF4976, 0x44EA8450 */ 347#define u4 2.28963728064692451092e-01 /* 0x3FCD4EAE, 0xF6010924 */ 348#define u5 1.33810918536787660377e-02 /* 0x3F8B678B, 0xBF2BAB09 */ 349 350#define v1 2.45597793713041134822e+00 /* 0x4003A5D7, 0xC2BD619C */ 351#define v2 2.12848976379893395361e+00 /* 0x40010725, 0xA42B18F5 */ 352#define v3 7.69285150456672783825e-01 /* 0x3FE89DFB, 0xE45050AF */ 353#define v4 1.04222645593369134254e-01 /* 0x3FBAAE55, 0xD6537C88 */ 354#define v5 3.21709242282423911810e-03 /* 0x3F6A5ABB, 0x57D0CF61 */ 355 356#define s0 -7.72156649015328655494e-02 /* 0xBFB3C467, 0xE37DB0C8 */ 357#define s1 2.14982415960608852501e-01 /* 0x3FCB848B, 0x36E20878 */ 358#define s2 3.25778796408930981787e-01 /* 0x3FD4D98F, 0x4F139F59 */ 359#define s3 1.46350472652464452805e-01 /* 0x3FC2BB9C, 0xBEE5F2F7 */ 360#define s4 2.66422703033638609560e-02 /* 0x3F9B481C, 0x7E939961 */ 361#define s5 1.84028451407337715652e-03 /* 0x3F5E26B6, 0x7368F239 */ 362#define s6 3.19475326584100867617e-05 /* 0x3F00BFEC, 0xDD17E945 */ 363 364#define r1 1.39200533467621045958e+00 /* 0x3FF645A7, 0x62C4AB74 */ 365#define r2 7.21935547567138069525e-01 /* 0x3FE71A18, 0x93D3DCDC */ 366#define r3 1.71933865632803078993e-01 /* 0x3FC601ED, 0xCCFBDF27 */ 367#define r4 1.86459191715652901344e-02 /* 0x3F9317EA, 0x742ED475 */ 368#define r5 7.77942496381893596434e-04 /* 0x3F497DDA, 0xCA41A95B */ 369#define r6 7.32668430744625636189e-06 /* 0x3EDEBAF7, 0xA5B38140 */ 370 371#define w0 4.18938533204672725052e-01 /* 0x3FDACFE3, 0x90C97D69 */ 372#define w1 8.33333333333329678849e-02 /* 0x3FB55555, 0x5555553B */ 373#define w2 -2.77777777728775536470e-03 /* 0xBF66C16C, 0x16B02E5C */ 374#define w3 7.93650558643019558500e-04 /* 0x3F4A019F, 0x98CF38B6 */ 375#define w4 -5.95187557450339963135e-04 /* 0xBF4380CB, 0x8C0FE741 */ 376#define w5 8.36339918996282139126e-04 /* 0x3F4B67BA, 0x4CDAD5D1 */ 377#define w6 -1.63092934096575273989e-03 /* 0xBF5AB89D, 0x0B9E43E4 */ 378 379_CLC_OVERLOAD _CLC_DEF double lgamma_r(double x, private int *ip) { 380 ulong ux = as_ulong(x); 381 ulong ax = ux & EXSIGNBIT_DP64; 382 double absx = as_double(ax); 383 384 if (ax >= 0x7ff0000000000000UL) { 385 // +-Inf, NaN 386 *ip = 1; 387 return absx; 388 } 389 390 if (absx < 0x1.0p-70) { 391 *ip = ax == ux ? 1 : -1; 392 return -log(absx); 393 } 394 395 // Handle rest of range 396 double r; 397 398 if (absx < 2.0) { 399 int i = 0; 400 double y = 2.0 - absx; 401 402 int c = absx < 0x1.bb4c3p+0; 403 double t = absx - tc; 404 i = c ? 1 : i; 405 y = c ? t : y; 406 407 c = absx < 0x1.3b4c4p+0; 408 t = absx - 1.0; 409 i = c ? 2 : i; 410 y = c ? t : y; 411 412 c = absx <= 0x1.cccccp-1; 413 t = -log(absx); 414 r = c ? t : 0.0; 415 t = 1.0 - absx; 416 i = c ? 0 : i; 417 y = c ? t : y; 418 419 c = absx < 0x1.76944p-1; 420 t = absx - (tc - 1.0); 421 i = c ? 1 : i; 422 y = c ? t : y; 423 424 c = absx < 0x1.da661p-3; 425 i = c ? 2 : i; 426 y = c ? absx : y; 427 428 double p, q; 429 430 switch (i) { 431 case 0: 432 p = fma(y, fma(y, fma(y, fma(y, a11, a10), a9), a8), a7); 433 p = fma(y, fma(y, fma(y, fma(y, p, a6), a5), a4), a3); 434 p = fma(y, fma(y, fma(y, p, a2), a1), a0); 435 r = fma(y, p - 0.5, r); 436 break; 437 case 1: 438 p = fma(y, fma(y, fma(y, fma(y, t14, t13), t12), t11), t10); 439 p = fma(y, fma(y, fma(y, fma(y, fma(y, p, t9), t8), t7), t6), t5); 440 p = fma(y, fma(y, fma(y, fma(y, fma(y, p, t4), t3), t2), t1), t0); 441 p = fma(y*y, p, -tt); 442 r += (tf + p); 443 break; 444 case 2: 445 p = y * fma(y, fma(y, fma(y, fma(y, fma(y, u5, u4), u3), u2), u1), u0); 446 q = fma(y, fma(y, fma(y, fma(y, fma(y, v5, v4), v3), v2), v1), 1.0); 447 r += fma(-0.5, y, p / q); 448 } 449 } else if (absx < 8.0) { 450 int i = absx; 451 double y = absx - (double) i; 452 double p = y * fma(y, fma(y, fma(y, fma(y, fma(y, fma(y, s6, s5), s4), s3), s2), s1), s0); 453 double q = fma(y, fma(y, fma(y, fma(y, fma(y, fma(y, r6, r5), r4), r3), r2), r1), 1.0); 454 r = fma(0.5, y, p / q); 455 double z = 1.0; 456 // lgamma(1+s) = log(s) + lgamma(s) 457 double y6 = y + 6.0; 458 double y5 = y + 5.0; 459 double y4 = y + 4.0; 460 double y3 = y + 3.0; 461 double y2 = y + 2.0; 462 z *= i > 6 ? y6 : 1.0; 463 z *= i > 5 ? y5 : 1.0; 464 z *= i > 4 ? y4 : 1.0; 465 z *= i > 3 ? y3 : 1.0; 466 z *= i > 2 ? y2 : 1.0; 467 r += log(z); 468 } else { 469 double z = 1.0 / absx; 470 double z2 = z * z; 471 double w = fma(z, fma(z2, fma(z2, fma(z2, fma(z2, fma(z2, w6, w5), w4), w3), w2), w1), w0); 472 r = (absx - 0.5) * (log(absx) - 1.0) + w; 473 } 474 475 if (x < 0.0) { 476 double t = sinpi(x); 477 r = log(pi / fabs(t * x)) - r; 478 r = t == 0.0 ? as_double(PINFBITPATT_DP64) : r; 479 *ip = t < 0.0 ? -1 : 1; 480 } else 481 *ip = 1; 482 483 return r; 484} 485 486_CLC_V_V_VP_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, lgamma_r, double, private, int) 487#endif 488 489 490#define __CLC_ADDRSPACE global 491#define __CLC_BODY <lgamma_r.inc> 492#include <clc/math/gentype.inc> 493#undef __CLC_ADDRSPACE 494 495#define __CLC_ADDRSPACE local 496#define __CLC_BODY <lgamma_r.inc> 497#include <clc/math/gentype.inc> 498#undef __CLC_ADDRSPACE 499