| 1 | /* j0l.c |
| 2 | * |
| 3 | * Bessel function of order zero |
| 4 | * |
| 5 | * |
| 6 | * |
| 7 | * SYNOPSIS: |
| 8 | * |
| 9 | * long double x, y, j0l(); |
| 10 | * |
| 11 | * y = j0l( x ); |
| 12 | * |
| 13 | * |
| 14 | * |
| 15 | * DESCRIPTION: |
| 16 | * |
| 17 | * Returns Bessel function of first kind, order zero of the argument. |
| 18 | * |
| 19 | * The domain is divided into two major intervals [0, 2] and |
| 20 | * (2, infinity). In the first interval the rational approximation |
| 21 | * is J0(x) = 1 - x^2 / 4 + x^4 R(x^2) |
| 22 | * The second interval is further partitioned into eight equal segments |
| 23 | * of 1/x. |
| 24 | * |
| 25 | * J0(x) = sqrt(2/(pi x)) (P0(x) cos(X) - Q0(x) sin(X)), |
| 26 | * X = x - pi/4, |
| 27 | * |
| 28 | * and the auxiliary functions are given by |
| 29 | * |
| 30 | * J0(x)cos(X) + Y0(x)sin(X) = sqrt( 2/(pi x)) P0(x), |
| 31 | * P0(x) = 1 + 1/x^2 R(1/x^2) |
| 32 | * |
| 33 | * Y0(x)cos(X) - J0(x)sin(X) = sqrt( 2/(pi x)) Q0(x), |
| 34 | * Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 35 | * |
| 36 | * |
| 37 | * |
| 38 | * ACCURACY: |
| 39 | * |
| 40 | * Absolute error: |
| 41 | * arithmetic domain # trials peak rms |
| 42 | * IEEE 0, 30 100000 1.7e-34 2.4e-35 |
| 43 | * |
| 44 | * |
| 45 | */ |
| 46 | |
| 47 | /* y0l.c |
| 48 | * |
| 49 | * Bessel function of the second kind, order zero |
| 50 | * |
| 51 | * |
| 52 | * |
| 53 | * SYNOPSIS: |
| 54 | * |
| 55 | * double x, y, y0l(); |
| 56 | * |
| 57 | * y = y0l( x ); |
| 58 | * |
| 59 | * |
| 60 | * |
| 61 | * DESCRIPTION: |
| 62 | * |
| 63 | * Returns Bessel function of the second kind, of order |
| 64 | * zero, of the argument. |
| 65 | * |
| 66 | * The approximation is the same as for J0(x), and |
| 67 | * Y0(x) = sqrt(2/(pi x)) (P0(x) sin(X) + Q0(x) cos(X)). |
| 68 | * |
| 69 | * ACCURACY: |
| 70 | * |
| 71 | * Absolute error, when y0(x) < 1; else relative error: |
| 72 | * |
| 73 | * arithmetic domain # trials peak rms |
| 74 | * IEEE 0, 30 100000 3.0e-34 2.7e-35 |
| 75 | * |
| 76 | */ |
| 77 | |
| 78 | /* Copyright 2001 by Stephen L. Moshier (moshier@na-net.ornl.gov). |
| 79 | |
| 80 | This library is free software; you can redistribute it and/or |
| 81 | modify it under the terms of the GNU Lesser General Public |
| 82 | License as published by the Free Software Foundation; either |
| 83 | version 2.1 of the License, or (at your option) any later version. |
| 84 | |
| 85 | This library is distributed in the hope that it will be useful, |
| 86 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 87 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 88 | Lesser General Public License for more details. |
| 89 | |
| 90 | You should have received a copy of the GNU Lesser General Public |
| 91 | License along with this library; if not, see |
| 92 | <https://www.gnu.org/licenses/>. */ |
| 93 | |
| 94 | #include <math.h> |
| 95 | #include <math_private.h> |
| 96 | #include <float.h> |
| 97 | #include <libm-alias-finite.h> |
| 98 | |
| 99 | /* 1 / sqrt(pi) */ |
| 100 | static const _Float128 ONEOSQPI = L(5.6418958354775628694807945156077258584405E-1); |
| 101 | /* 2 / pi */ |
| 102 | static const _Float128 TWOOPI = L(6.3661977236758134307553505349005744813784E-1); |
| 103 | static const _Float128 zero = 0; |
| 104 | |
| 105 | /* J0(x) = 1 - x^2/4 + x^2 x^2 R(x^2) |
| 106 | Peak relative error 3.4e-37 |
| 107 | 0 <= x <= 2 */ |
| 108 | #define NJ0_2N 6 |
| 109 | static const _Float128 J0_2N[NJ0_2N + 1] = { |
| 110 | L(3.133239376997663645548490085151484674892E16), |
| 111 | L(-5.479944965767990821079467311839107722107E14), |
| 112 | L(6.290828903904724265980249871997551894090E12), |
| 113 | L(-3.633750176832769659849028554429106299915E10), |
| 114 | L(1.207743757532429576399485415069244807022E8), |
| 115 | L(-2.107485999925074577174305650549367415465E5), |
| 116 | L(1.562826808020631846245296572935547005859E2), |
| 117 | }; |
| 118 | #define NJ0_2D 6 |
| 119 | static const _Float128 J0_2D[NJ0_2D + 1] = { |
| 120 | L(2.005273201278504733151033654496928968261E18), |
| 121 | L(2.063038558793221244373123294054149790864E16), |
| 122 | L(1.053350447931127971406896594022010524994E14), |
| 123 | L(3.496556557558702583143527876385508882310E11), |
| 124 | L(8.249114511878616075860654484367133976306E8), |
| 125 | L(1.402965782449571800199759247964242790589E6), |
| 126 | L(1.619910762853439600957801751815074787351E3), |
| 127 | /* 1.000000000000000000000000000000000000000E0 */ |
| 128 | }; |
| 129 | |
| 130 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2), |
| 131 | 0 <= 1/x <= .0625 |
| 132 | Peak relative error 3.3e-36 */ |
| 133 | #define NP16_IN 9 |
| 134 | static const _Float128 P16_IN[NP16_IN + 1] = { |
| 135 | L(-1.901689868258117463979611259731176301065E-16), |
| 136 | L(-1.798743043824071514483008340803573980931E-13), |
| 137 | L(-6.481746687115262291873324132944647438959E-11), |
| 138 | L(-1.150651553745409037257197798528294248012E-8), |
| 139 | L(-1.088408467297401082271185599507222695995E-6), |
| 140 | L(-5.551996725183495852661022587879817546508E-5), |
| 141 | L(-1.477286941214245433866838787454880214736E-3), |
| 142 | L(-1.882877976157714592017345347609200402472E-2), |
| 143 | L(-9.620983176855405325086530374317855880515E-2), |
| 144 | L(-1.271468546258855781530458854476627766233E-1), |
| 145 | }; |
| 146 | #define NP16_ID 9 |
| 147 | static const _Float128 P16_ID[NP16_ID + 1] = { |
| 148 | L(2.704625590411544837659891569420764475007E-15), |
| 149 | L(2.562526347676857624104306349421985403573E-12), |
| 150 | L(9.259137589952741054108665570122085036246E-10), |
| 151 | L(1.651044705794378365237454962653430805272E-7), |
| 152 | L(1.573561544138733044977714063100859136660E-5), |
| 153 | L(8.134482112334882274688298469629884804056E-4), |
| 154 | L(2.219259239404080863919375103673593571689E-2), |
| 155 | L(2.976990606226596289580242451096393862792E-1), |
| 156 | L(1.713895630454693931742734911930937246254E0), |
| 157 | L(3.231552290717904041465898249160757368855E0), |
| 158 | /* 1.000000000000000000000000000000000000000E0 */ |
| 159 | }; |
| 160 | |
| 161 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2) |
| 162 | 0.0625 <= 1/x <= 0.125 |
| 163 | Peak relative error 2.4e-35 */ |
| 164 | #define NP8_16N 10 |
| 165 | static const _Float128 P8_16N[NP8_16N + 1] = { |
| 166 | L(-2.335166846111159458466553806683579003632E-15), |
| 167 | L(-1.382763674252402720401020004169367089975E-12), |
| 168 | L(-3.192160804534716696058987967592784857907E-10), |
| 169 | L(-3.744199606283752333686144670572632116899E-8), |
| 170 | L(-2.439161236879511162078619292571922772224E-6), |
| 171 | L(-9.068436986859420951664151060267045346549E-5), |
| 172 | L(-1.905407090637058116299757292660002697359E-3), |
| 173 | L(-2.164456143936718388053842376884252978872E-2), |
| 174 | L(-1.212178415116411222341491717748696499966E-1), |
| 175 | L(-2.782433626588541494473277445959593334494E-1), |
| 176 | L(-1.670703190068873186016102289227646035035E-1), |
| 177 | }; |
| 178 | #define NP8_16D 10 |
| 179 | static const _Float128 P8_16D[NP8_16D + 1] = { |
| 180 | L(3.321126181135871232648331450082662856743E-14), |
| 181 | L(1.971894594837650840586859228510007703641E-11), |
| 182 | L(4.571144364787008285981633719513897281690E-9), |
| 183 | L(5.396419143536287457142904742849052402103E-7), |
| 184 | L(3.551548222385845912370226756036899901549E-5), |
| 185 | L(1.342353874566932014705609788054598013516E-3), |
| 186 | L(2.899133293006771317589357444614157734385E-2), |
| 187 | L(3.455374978185770197704507681491574261545E-1), |
| 188 | L(2.116616964297512311314454834712634820514E0), |
| 189 | L(5.850768316827915470087758636881584174432E0), |
| 190 | L(5.655273858938766830855753983631132928968E0), |
| 191 | /* 1.000000000000000000000000000000000000000E0 */ |
| 192 | }; |
| 193 | |
| 194 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2) |
| 195 | 0.125 <= 1/x <= 0.1875 |
| 196 | Peak relative error 2.7e-35 */ |
| 197 | #define NP5_8N 10 |
| 198 | static const _Float128 P5_8N[NP5_8N + 1] = { |
| 199 | L(-1.270478335089770355749591358934012019596E-12), |
| 200 | L(-4.007588712145412921057254992155810347245E-10), |
| 201 | L(-4.815187822989597568124520080486652009281E-8), |
| 202 | L(-2.867070063972764880024598300408284868021E-6), |
| 203 | L(-9.218742195161302204046454768106063638006E-5), |
| 204 | L(-1.635746821447052827526320629828043529997E-3), |
| 205 | L(-1.570376886640308408247709616497261011707E-2), |
| 206 | L(-7.656484795303305596941813361786219477807E-2), |
| 207 | L(-1.659371030767513274944805479908858628053E-1), |
| 208 | L(-1.185340550030955660015841796219919804915E-1), |
| 209 | L(-8.920026499909994671248893388013790366712E-3), |
| 210 | }; |
| 211 | #define NP5_8D 9 |
| 212 | static const _Float128 P5_8D[NP5_8D + 1] = { |
| 213 | L(1.806902521016705225778045904631543990314E-11), |
| 214 | L(5.728502760243502431663549179135868966031E-9), |
| 215 | L(6.938168504826004255287618819550667978450E-7), |
| 216 | L(4.183769964807453250763325026573037785902E-5), |
| 217 | L(1.372660678476925468014882230851637878587E-3), |
| 218 | L(2.516452105242920335873286419212708961771E-2), |
| 219 | L(2.550502712902647803796267951846557316182E-1), |
| 220 | L(1.365861559418983216913629123778747617072E0), |
| 221 | L(3.523825618308783966723472468855042541407E0), |
| 222 | L(3.656365803506136165615111349150536282434E0), |
| 223 | /* 1.000000000000000000000000000000000000000E0 */ |
| 224 | }; |
| 225 | |
| 226 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2) |
| 227 | Peak relative error 3.5e-35 |
| 228 | 0.1875 <= 1/x <= 0.25 */ |
| 229 | #define NP4_5N 9 |
| 230 | static const _Float128 P4_5N[NP4_5N + 1] = { |
| 231 | L(-9.791405771694098960254468859195175708252E-10), |
| 232 | L(-1.917193059944531970421626610188102836352E-7), |
| 233 | L(-1.393597539508855262243816152893982002084E-5), |
| 234 | L(-4.881863490846771259880606911667479860077E-4), |
| 235 | L(-8.946571245022470127331892085881699269853E-3), |
| 236 | L(-8.707474232568097513415336886103899434251E-2), |
| 237 | L(-4.362042697474650737898551272505525973766E-1), |
| 238 | L(-1.032712171267523975431451359962375617386E0), |
| 239 | L(-9.630502683169895107062182070514713702346E-1), |
| 240 | L(-2.251804386252969656586810309252357233320E-1), |
| 241 | }; |
| 242 | #define NP4_5D 9 |
| 243 | static const _Float128 P4_5D[NP4_5D + 1] = { |
| 244 | L(1.392555487577717669739688337895791213139E-8), |
| 245 | L(2.748886559120659027172816051276451376854E-6), |
| 246 | L(2.024717710644378047477189849678576659290E-4), |
| 247 | L(7.244868609350416002930624752604670292469E-3), |
| 248 | L(1.373631762292244371102989739300382152416E-1), |
| 249 | L(1.412298581400224267910294815260613240668E0), |
| 250 | L(7.742495637843445079276397723849017617210E0), |
| 251 | L(2.138429269198406512028307045259503811861E1), |
| 252 | L(2.651547684548423476506826951831712762610E1), |
| 253 | L(1.167499382465291931571685222882909166935E1), |
| 254 | /* 1.000000000000000000000000000000000000000E0 */ |
| 255 | }; |
| 256 | |
| 257 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2) |
| 258 | Peak relative error 2.3e-36 |
| 259 | 0.25 <= 1/x <= 0.3125 */ |
| 260 | #define NP3r2_4N 9 |
| 261 | static const _Float128 P3r2_4N[NP3r2_4N + 1] = { |
| 262 | L(-2.589155123706348361249809342508270121788E-8), |
| 263 | L(-3.746254369796115441118148490849195516593E-6), |
| 264 | L(-1.985595497390808544622893738135529701062E-4), |
| 265 | L(-5.008253705202932091290132760394976551426E-3), |
| 266 | L(-6.529469780539591572179155511840853077232E-2), |
| 267 | L(-4.468736064761814602927408833818990271514E-1), |
| 268 | L(-1.556391252586395038089729428444444823380E0), |
| 269 | L(-2.533135309840530224072920725976994981638E0), |
| 270 | L(-1.605509621731068453869408718565392869560E0), |
| 271 | L(-2.518966692256192789269859830255724429375E-1), |
| 272 | }; |
| 273 | #define NP3r2_4D 9 |
| 274 | static const _Float128 P3r2_4D[NP3r2_4D + 1] = { |
| 275 | L(3.682353957237979993646169732962573930237E-7), |
| 276 | L(5.386741661883067824698973455566332102029E-5), |
| 277 | L(2.906881154171822780345134853794241037053E-3), |
| 278 | L(7.545832595801289519475806339863492074126E-2), |
| 279 | L(1.029405357245594877344360389469584526654E0), |
| 280 | L(7.565706120589873131187989560509757626725E0), |
| 281 | L(2.951172890699569545357692207898667665796E1), |
| 282 | L(5.785723537170311456298467310529815457536E1), |
| 283 | L(5.095621464598267889126015412522773474467E1), |
| 284 | L(1.602958484169953109437547474953308401442E1), |
| 285 | /* 1.000000000000000000000000000000000000000E0 */ |
| 286 | }; |
| 287 | |
| 288 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2) |
| 289 | Peak relative error 1.0e-35 |
| 290 | 0.3125 <= 1/x <= 0.375 */ |
| 291 | #define NP2r7_3r2N 9 |
| 292 | static const _Float128 P2r7_3r2N[NP2r7_3r2N + 1] = { |
| 293 | L(-1.917322340814391131073820537027234322550E-7), |
| 294 | L(-1.966595744473227183846019639723259011906E-5), |
| 295 | L(-7.177081163619679403212623526632690465290E-4), |
| 296 | L(-1.206467373860974695661544653741899755695E-2), |
| 297 | L(-1.008656452188539812154551482286328107316E-1), |
| 298 | L(-4.216016116408810856620947307438823892707E-1), |
| 299 | L(-8.378631013025721741744285026537009814161E-1), |
| 300 | L(-6.973895635309960850033762745957946272579E-1), |
| 301 | L(-1.797864718878320770670740413285763554812E-1), |
| 302 | L(-4.098025357743657347681137871388402849581E-3), |
| 303 | }; |
| 304 | #define NP2r7_3r2D 8 |
| 305 | static const _Float128 P2r7_3r2D[NP2r7_3r2D + 1] = { |
| 306 | L(2.726858489303036441686496086962545034018E-6), |
| 307 | L(2.840430827557109238386808968234848081424E-4), |
| 308 | L(1.063826772041781947891481054529454088832E-2), |
| 309 | L(1.864775537138364773178044431045514405468E-1), |
| 310 | L(1.665660052857205170440952607701728254211E0), |
| 311 | L(7.723745889544331153080842168958348568395E0), |
| 312 | L(1.810726427571829798856428548102077799835E1), |
| 313 | L(1.986460672157794440666187503833545388527E1), |
| 314 | L(8.645503204552282306364296517220055815488E0), |
| 315 | /* 1.000000000000000000000000000000000000000E0 */ |
| 316 | }; |
| 317 | |
| 318 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2) |
| 319 | Peak relative error 1.3e-36 |
| 320 | 0.3125 <= 1/x <= 0.4375 */ |
| 321 | #define NP2r3_2r7N 9 |
| 322 | static const _Float128 P2r3_2r7N[NP2r3_2r7N + 1] = { |
| 323 | L(-1.594642785584856746358609622003310312622E-6), |
| 324 | L(-1.323238196302221554194031733595194539794E-4), |
| 325 | L(-3.856087818696874802689922536987100372345E-3), |
| 326 | L(-5.113241710697777193011470733601522047399E-2), |
| 327 | L(-3.334229537209911914449990372942022350558E-1), |
| 328 | L(-1.075703518198127096179198549659283422832E0), |
| 329 | L(-1.634174803414062725476343124267110981807E0), |
| 330 | L(-1.030133247434119595616826842367268304880E0), |
| 331 | L(-1.989811539080358501229347481000707289391E-1), |
| 332 | L(-3.246859189246653459359775001466924610236E-3), |
| 333 | }; |
| 334 | #define NP2r3_2r7D 8 |
| 335 | static const _Float128 P2r3_2r7D[NP2r3_2r7D + 1] = { |
| 336 | L(2.267936634217251403663034189684284173018E-5), |
| 337 | L(1.918112982168673386858072491437971732237E-3), |
| 338 | L(5.771704085468423159125856786653868219522E-2), |
| 339 | L(8.056124451167969333717642810661498890507E-1), |
| 340 | L(5.687897967531010276788680634413789328776E0), |
| 341 | L(2.072596760717695491085444438270778394421E1), |
| 342 | L(3.801722099819929988585197088613160496684E1), |
| 343 | L(3.254620235902912339534998592085115836829E1), |
| 344 | L(1.104847772130720331801884344645060675036E1), |
| 345 | /* 1.000000000000000000000000000000000000000E0 */ |
| 346 | }; |
| 347 | |
| 348 | /* J0(x)cosX + Y0(x)sinX = sqrt( 2/(pi x)) P0(x), P0(x) = 1 + 1/x^2 R(1/x^2) |
| 349 | Peak relative error 1.2e-35 |
| 350 | 0.4375 <= 1/x <= 0.5 */ |
| 351 | #define NP2_2r3N 8 |
| 352 | static const _Float128 P2_2r3N[NP2_2r3N + 1] = { |
| 353 | L(-1.001042324337684297465071506097365389123E-4), |
| 354 | L(-6.289034524673365824853547252689991418981E-3), |
| 355 | L(-1.346527918018624234373664526930736205806E-1), |
| 356 | L(-1.268808313614288355444506172560463315102E0), |
| 357 | L(-5.654126123607146048354132115649177406163E0), |
| 358 | L(-1.186649511267312652171775803270911971693E1), |
| 359 | L(-1.094032424931998612551588246779200724257E1), |
| 360 | L(-3.728792136814520055025256353193674625267E0), |
| 361 | L(-3.000348318524471807839934764596331810608E-1), |
| 362 | }; |
| 363 | #define NP2_2r3D 8 |
| 364 | static const _Float128 P2_2r3D[NP2_2r3D + 1] = { |
| 365 | L(1.423705538269770974803901422532055612980E-3), |
| 366 | L(9.171476630091439978533535167485230575894E-2), |
| 367 | L(2.049776318166637248868444600215942828537E0), |
| 368 | L(2.068970329743769804547326701946144899583E1), |
| 369 | L(1.025103500560831035592731539565060347709E2), |
| 370 | L(2.528088049697570728252145557167066708284E2), |
| 371 | L(2.992160327587558573740271294804830114205E2), |
| 372 | L(1.540193761146551025832707739468679973036E2), |
| 373 | L(2.779516701986912132637672140709452502650E1), |
| 374 | /* 1.000000000000000000000000000000000000000E0 */ |
| 375 | }; |
| 376 | |
| 377 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 378 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 379 | Peak relative error 2.2e-35 |
| 380 | 0 <= 1/x <= .0625 */ |
| 381 | #define NQ16_IN 10 |
| 382 | static const _Float128 Q16_IN[NQ16_IN + 1] = { |
| 383 | L(2.343640834407975740545326632205999437469E-18), |
| 384 | L(2.667978112927811452221176781536278257448E-15), |
| 385 | L(1.178415018484555397390098879501969116536E-12), |
| 386 | L(2.622049767502719728905924701288614016597E-10), |
| 387 | L(3.196908059607618864801313380896308968673E-8), |
| 388 | L(2.179466154171673958770030655199434798494E-6), |
| 389 | L(8.139959091628545225221976413795645177291E-5), |
| 390 | L(1.563900725721039825236927137885747138654E-3), |
| 391 | L(1.355172364265825167113562519307194840307E-2), |
| 392 | L(3.928058355906967977269780046844768588532E-2), |
| 393 | L(1.107891967702173292405380993183694932208E-2), |
| 394 | }; |
| 395 | #define NQ16_ID 9 |
| 396 | static const _Float128 Q16_ID[NQ16_ID + 1] = { |
| 397 | L(3.199850952578356211091219295199301766718E-17), |
| 398 | L(3.652601488020654842194486058637953363918E-14), |
| 399 | L(1.620179741394865258354608590461839031281E-11), |
| 400 | L(3.629359209474609630056463248923684371426E-9), |
| 401 | L(4.473680923894354600193264347733477363305E-7), |
| 402 | L(3.106368086644715743265603656011050476736E-5), |
| 403 | L(1.198239259946770604954664925153424252622E-3), |
| 404 | L(2.446041004004283102372887804475767568272E-2), |
| 405 | L(2.403235525011860603014707768815113698768E-1), |
| 406 | L(9.491006790682158612266270665136910927149E-1), |
| 407 | /* 1.000000000000000000000000000000000000000E0 */ |
| 408 | }; |
| 409 | |
| 410 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 411 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 412 | Peak relative error 5.1e-36 |
| 413 | 0.0625 <= 1/x <= 0.125 */ |
| 414 | #define NQ8_16N 11 |
| 415 | static const _Float128 Q8_16N[NQ8_16N + 1] = { |
| 416 | L(1.001954266485599464105669390693597125904E-17), |
| 417 | L(7.545499865295034556206475956620160007849E-15), |
| 418 | L(2.267838684785673931024792538193202559922E-12), |
| 419 | L(3.561909705814420373609574999542459912419E-10), |
| 420 | L(3.216201422768092505214730633842924944671E-8), |
| 421 | L(1.731194793857907454569364622452058554314E-6), |
| 422 | L(5.576944613034537050396518509871004586039E-5), |
| 423 | L(1.051787760316848982655967052985391418146E-3), |
| 424 | L(1.102852974036687441600678598019883746959E-2), |
| 425 | L(5.834647019292460494254225988766702933571E-2), |
| 426 | L(1.290281921604364618912425380717127576529E-1), |
| 427 | L(7.598886310387075708640370806458926458301E-2), |
| 428 | }; |
| 429 | #define NQ8_16D 11 |
| 430 | static const _Float128 Q8_16D[NQ8_16D + 1] = { |
| 431 | L(1.368001558508338469503329967729951830843E-16), |
| 432 | L(1.034454121857542147020549303317348297289E-13), |
| 433 | L(3.128109209247090744354764050629381674436E-11), |
| 434 | L(4.957795214328501986562102573522064468671E-9), |
| 435 | L(4.537872468606711261992676606899273588899E-7), |
| 436 | L(2.493639207101727713192687060517509774182E-5), |
| 437 | L(8.294957278145328349785532236663051405805E-4), |
| 438 | L(1.646471258966713577374948205279380115839E-2), |
| 439 | L(1.878910092770966718491814497982191447073E-1), |
| 440 | L(1.152641605706170353727903052525652504075E0), |
| 441 | L(3.383550240669773485412333679367792932235E0), |
| 442 | L(3.823875252882035706910024716609908473970E0), |
| 443 | /* 1.000000000000000000000000000000000000000E0 */ |
| 444 | }; |
| 445 | |
| 446 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 447 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 448 | Peak relative error 3.9e-35 |
| 449 | 0.125 <= 1/x <= 0.1875 */ |
| 450 | #define NQ5_8N 10 |
| 451 | static const _Float128 Q5_8N[NQ5_8N + 1] = { |
| 452 | L(1.750399094021293722243426623211733898747E-13), |
| 453 | L(6.483426211748008735242909236490115050294E-11), |
| 454 | L(9.279430665656575457141747875716899958373E-9), |
| 455 | L(6.696634968526907231258534757736576340266E-7), |
| 456 | L(2.666560823798895649685231292142838188061E-5), |
| 457 | L(6.025087697259436271271562769707550594540E-4), |
| 458 | L(7.652807734168613251901945778921336353485E-3), |
| 459 | L(5.226269002589406461622551452343519078905E-2), |
| 460 | L(1.748390159751117658969324896330142895079E-1), |
| 461 | L(2.378188719097006494782174902213083589660E-1), |
| 462 | L(8.383984859679804095463699702165659216831E-2), |
| 463 | }; |
| 464 | #define NQ5_8D 10 |
| 465 | static const _Float128 Q5_8D[NQ5_8D + 1] = { |
| 466 | L(2.389878229704327939008104855942987615715E-12), |
| 467 | L(8.926142817142546018703814194987786425099E-10), |
| 468 | L(1.294065862406745901206588525833274399038E-7), |
| 469 | L(9.524139899457666250828752185212769682191E-6), |
| 470 | L(3.908332488377770886091936221573123353489E-4), |
| 471 | L(9.250427033957236609624199884089916836748E-3), |
| 472 | L(1.263420066165922645975830877751588421451E-1), |
| 473 | L(9.692527053860420229711317379861733180654E-1), |
| 474 | L(3.937813834630430172221329298841520707954E0), |
| 475 | L(7.603126427436356534498908111445191312181E0), |
| 476 | L(5.670677653334105479259958485084550934305E0), |
| 477 | /* 1.000000000000000000000000000000000000000E0 */ |
| 478 | }; |
| 479 | |
| 480 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 481 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 482 | Peak relative error 3.2e-35 |
| 483 | 0.1875 <= 1/x <= 0.25 */ |
| 484 | #define NQ4_5N 10 |
| 485 | static const _Float128 Q4_5N[NQ4_5N + 1] = { |
| 486 | L(2.233870042925895644234072357400122854086E-11), |
| 487 | L(5.146223225761993222808463878999151699792E-9), |
| 488 | L(4.459114531468296461688753521109797474523E-7), |
| 489 | L(1.891397692931537975547242165291668056276E-5), |
| 490 | L(4.279519145911541776938964806470674565504E-4), |
| 491 | L(5.275239415656560634702073291768904783989E-3), |
| 492 | L(3.468698403240744801278238473898432608887E-2), |
| 493 | L(1.138773146337708415188856882915457888274E-1), |
| 494 | L(1.622717518946443013587108598334636458955E-1), |
| 495 | L(7.249040006390586123760992346453034628227E-2), |
| 496 | L(1.941595365256460232175236758506411486667E-3), |
| 497 | }; |
| 498 | #define NQ4_5D 9 |
| 499 | static const _Float128 Q4_5D[NQ4_5D + 1] = { |
| 500 | L(3.049977232266999249626430127217988047453E-10), |
| 501 | L(7.120883230531035857746096928889676144099E-8), |
| 502 | L(6.301786064753734446784637919554359588859E-6), |
| 503 | L(2.762010530095069598480766869426308077192E-4), |
| 504 | L(6.572163250572867859316828886203406361251E-3), |
| 505 | L(8.752566114841221958200215255461843397776E-2), |
| 506 | L(6.487654992874805093499285311075289932664E-1), |
| 507 | L(2.576550017826654579451615283022812801435E0), |
| 508 | L(5.056392229924022835364779562707348096036E0), |
| 509 | L(4.179770081068251464907531367859072157773E0), |
| 510 | /* 1.000000000000000000000000000000000000000E0 */ |
| 511 | }; |
| 512 | |
| 513 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 514 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 515 | Peak relative error 1.4e-36 |
| 516 | 0.25 <= 1/x <= 0.3125 */ |
| 517 | #define NQ3r2_4N 10 |
| 518 | static const _Float128 Q3r2_4N[NQ3r2_4N + 1] = { |
| 519 | L(6.126167301024815034423262653066023684411E-10), |
| 520 | L(1.043969327113173261820028225053598975128E-7), |
| 521 | L(6.592927270288697027757438170153763220190E-6), |
| 522 | L(2.009103660938497963095652951912071336730E-4), |
| 523 | L(3.220543385492643525985862356352195896964E-3), |
| 524 | L(2.774405975730545157543417650436941650990E-2), |
| 525 | L(1.258114008023826384487378016636555041129E-1), |
| 526 | L(2.811724258266902502344701449984698323860E-1), |
| 527 | L(2.691837665193548059322831687432415014067E-1), |
| 528 | L(7.949087384900985370683770525312735605034E-2), |
| 529 | L(1.229509543620976530030153018986910810747E-3), |
| 530 | }; |
| 531 | #define NQ3r2_4D 9 |
| 532 | static const _Float128 Q3r2_4D[NQ3r2_4D + 1] = { |
| 533 | L(8.364260446128475461539941389210166156568E-9), |
| 534 | L(1.451301850638956578622154585560759862764E-6), |
| 535 | L(9.431830010924603664244578867057141839463E-5), |
| 536 | L(3.004105101667433434196388593004526182741E-3), |
| 537 | L(5.148157397848271739710011717102773780221E-2), |
| 538 | L(4.901089301726939576055285374953887874895E-1), |
| 539 | L(2.581760991981709901216967665934142240346E0), |
| 540 | L(7.257105880775059281391729708630912791847E0), |
| 541 | L(1.006014717326362868007913423810737369312E1), |
| 542 | L(5.879416600465399514404064187445293212470E0), |
| 543 | /* 1.000000000000000000000000000000000000000E0*/ |
| 544 | }; |
| 545 | |
| 546 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 547 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 548 | Peak relative error 3.8e-36 |
| 549 | 0.3125 <= 1/x <= 0.375 */ |
| 550 | #define NQ2r7_3r2N 9 |
| 551 | static const _Float128 Q2r7_3r2N[NQ2r7_3r2N + 1] = { |
| 552 | L(7.584861620402450302063691901886141875454E-8), |
| 553 | L(9.300939338814216296064659459966041794591E-6), |
| 554 | L(4.112108906197521696032158235392604947895E-4), |
| 555 | L(8.515168851578898791897038357239630654431E-3), |
| 556 | L(8.971286321017307400142720556749573229058E-2), |
| 557 | L(4.885856732902956303343015636331874194498E-1), |
| 558 | L(1.334506268733103291656253500506406045846E0), |
| 559 | L(1.681207956863028164179042145803851824654E0), |
| 560 | L(8.165042692571721959157677701625853772271E-1), |
| 561 | L(9.805848115375053300608712721986235900715E-2), |
| 562 | }; |
| 563 | #define NQ2r7_3r2D 9 |
| 564 | static const _Float128 Q2r7_3r2D[NQ2r7_3r2D + 1] = { |
| 565 | L(1.035586492113036586458163971239438078160E-6), |
| 566 | L(1.301999337731768381683593636500979713689E-4), |
| 567 | L(5.993695702564527062553071126719088859654E-3), |
| 568 | L(1.321184892887881883489141186815457808785E-1), |
| 569 | L(1.528766555485015021144963194165165083312E0), |
| 570 | L(9.561463309176490874525827051566494939295E0), |
| 571 | L(3.203719484883967351729513662089163356911E1), |
| 572 | L(5.497294687660930446641539152123568668447E1), |
| 573 | L(4.391158169390578768508675452986948391118E1), |
| 574 | L(1.347836630730048077907818943625789418378E1), |
| 575 | /* 1.000000000000000000000000000000000000000E0 */ |
| 576 | }; |
| 577 | |
| 578 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 579 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 580 | Peak relative error 2.2e-35 |
| 581 | 0.375 <= 1/x <= 0.4375 */ |
| 582 | #define NQ2r3_2r7N 9 |
| 583 | static const _Float128 Q2r3_2r7N[NQ2r3_2r7N + 1] = { |
| 584 | L(4.455027774980750211349941766420190722088E-7), |
| 585 | L(4.031998274578520170631601850866780366466E-5), |
| 586 | L(1.273987274325947007856695677491340636339E-3), |
| 587 | L(1.818754543377448509897226554179659122873E-2), |
| 588 | L(1.266748858326568264126353051352269875352E-1), |
| 589 | L(4.327578594728723821137731555139472880414E-1), |
| 590 | L(6.892532471436503074928194969154192615359E-1), |
| 591 | L(4.490775818438716873422163588640262036506E-1), |
| 592 | L(8.649615949297322440032000346117031581572E-2), |
| 593 | L(7.261345286655345047417257611469066147561E-4), |
| 594 | }; |
| 595 | #define NQ2r3_2r7D 8 |
| 596 | static const _Float128 Q2r3_2r7D[NQ2r3_2r7D + 1] = { |
| 597 | L(6.082600739680555266312417978064954793142E-6), |
| 598 | L(5.693622538165494742945717226571441747567E-4), |
| 599 | L(1.901625907009092204458328768129666975975E-2), |
| 600 | L(2.958689532697857335456896889409923371570E-1), |
| 601 | L(2.343124711045660081603809437993368799568E0), |
| 602 | L(9.665894032187458293568704885528192804376E0), |
| 603 | L(2.035273104990617136065743426322454881353E1), |
| 604 | L(2.044102010478792896815088858740075165531E1), |
| 605 | L(8.445937177863155827844146643468706599304E0), |
| 606 | /* 1.000000000000000000000000000000000000000E0 */ |
| 607 | }; |
| 608 | |
| 609 | /* Y0(x)cosX - J0(x)sinX = sqrt( 2/(pi x)) Q0(x), |
| 610 | Q0(x) = 1/x (-.125 + 1/x^2 R(1/x^2)) |
| 611 | Peak relative error 3.1e-36 |
| 612 | 0.4375 <= 1/x <= 0.5 */ |
| 613 | #define NQ2_2r3N 9 |
| 614 | static const _Float128 Q2_2r3N[NQ2_2r3N + 1] = { |
| 615 | L(2.817566786579768804844367382809101929314E-6), |
| 616 | L(2.122772176396691634147024348373539744935E-4), |
| 617 | L(5.501378031780457828919593905395747517585E-3), |
| 618 | L(6.355374424341762686099147452020466524659E-2), |
| 619 | L(3.539652320122661637429658698954748337223E-1), |
| 620 | L(9.571721066119617436343740541777014319695E-1), |
| 621 | L(1.196258777828426399432550698612171955305E0), |
| 622 | L(6.069388659458926158392384709893753793967E-1), |
| 623 | L(9.026746127269713176512359976978248763621E-2), |
| 624 | L(5.317668723070450235320878117210807236375E-4), |
| 625 | }; |
| 626 | #define NQ2_2r3D 8 |
| 627 | static const _Float128 Q2_2r3D[NQ2_2r3D + 1] = { |
| 628 | L(3.846924354014260866793741072933159380158E-5), |
| 629 | L(3.017562820057704325510067178327449946763E-3), |
| 630 | L(8.356305620686867949798885808540444210935E-2), |
| 631 | L(1.068314930499906838814019619594424586273E0), |
| 632 | L(6.900279623894821067017966573640732685233E0), |
| 633 | L(2.307667390886377924509090271780839563141E1), |
| 634 | L(3.921043465412723970791036825401273528513E1), |
| 635 | L(3.167569478939719383241775717095729233436E1), |
| 636 | L(1.051023841699200920276198346301543665909E1), |
| 637 | /* 1.000000000000000000000000000000000000000E0*/ |
| 638 | }; |
| 639 | |
| 640 | |
| 641 | /* Evaluate P[n] x^n + P[n-1] x^(n-1) + ... + P[0] */ |
| 642 | |
| 643 | static _Float128 |
| 644 | neval (_Float128 x, const _Float128 *p, int n) |
| 645 | { |
| 646 | _Float128 y; |
| 647 | |
| 648 | p += n; |
| 649 | y = *p--; |
| 650 | do |
| 651 | { |
| 652 | y = y * x + *p--; |
| 653 | } |
| 654 | while (--n > 0); |
| 655 | return y; |
| 656 | } |
| 657 | |
| 658 | |
| 659 | /* Evaluate x^n+1 + P[n] x^(n) + P[n-1] x^(n-1) + ... + P[0] */ |
| 660 | |
| 661 | static _Float128 |
| 662 | deval (_Float128 x, const _Float128 *p, int n) |
| 663 | { |
| 664 | _Float128 y; |
| 665 | |
| 666 | p += n; |
| 667 | y = x + *p--; |
| 668 | do |
| 669 | { |
| 670 | y = y * x + *p--; |
| 671 | } |
| 672 | while (--n > 0); |
| 673 | return y; |
| 674 | } |
| 675 | |
| 676 | |
| 677 | /* Bessel function of the first kind, order zero. */ |
| 678 | |
| 679 | _Float128 |
| 680 | __ieee754_j0l (_Float128 x) |
| 681 | { |
| 682 | _Float128 xx, xinv, z, p, q, c, s, cc, ss; |
| 683 | |
| 684 | if (! isfinite (x)) |
| 685 | { |
| 686 | if (x != x) |
| 687 | return x + x; |
| 688 | else |
| 689 | return 0; |
| 690 | } |
| 691 | if (x == 0) |
| 692 | return 1; |
| 693 | |
| 694 | xx = fabsl (x); |
| 695 | if (xx <= 2) |
| 696 | { |
| 697 | if (xx < L(0x1p-57)) |
| 698 | return 1; |
| 699 | /* 0 <= x <= 2 */ |
| 700 | z = xx * xx; |
| 701 | p = z * z * neval (z, J0_2N, NJ0_2N) / deval (z, J0_2D, NJ0_2D); |
| 702 | p -= L(0.25) * z; |
| 703 | p += 1; |
| 704 | return p; |
| 705 | } |
| 706 | |
| 707 | /* X = x - pi/4 |
| 708 | cos(X) = cos(x) cos(pi/4) + sin(x) sin(pi/4) |
| 709 | = 1/sqrt(2) * (cos(x) + sin(x)) |
| 710 | sin(X) = sin(x) cos(pi/4) - cos(x) sin(pi/4) |
| 711 | = 1/sqrt(2) * (sin(x) - cos(x)) |
| 712 | sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x)) |
| 713 | cf. Fdlibm. */ |
| 714 | __sincosl (xx, &s, &c); |
| 715 | ss = s - c; |
| 716 | cc = s + c; |
| 717 | if (xx <= LDBL_MAX / 2) |
| 718 | { |
| 719 | z = -__cosl (xx + xx); |
| 720 | if ((s * c) < 0) |
| 721 | cc = z / ss; |
| 722 | else |
| 723 | ss = z / cc; |
| 724 | } |
| 725 | |
| 726 | if (xx > L(0x1p256)) |
| 727 | return ONEOSQPI * cc / sqrtl (xx); |
| 728 | |
| 729 | xinv = 1 / xx; |
| 730 | z = xinv * xinv; |
| 731 | if (xinv <= 0.25) |
| 732 | { |
| 733 | if (xinv <= 0.125) |
| 734 | { |
| 735 | if (xinv <= 0.0625) |
| 736 | { |
| 737 | p = neval (z, P16_IN, NP16_IN) / deval (z, P16_ID, NP16_ID); |
| 738 | q = neval (z, Q16_IN, NQ16_IN) / deval (z, Q16_ID, NQ16_ID); |
| 739 | } |
| 740 | else |
| 741 | { |
| 742 | p = neval (z, P8_16N, NP8_16N) / deval (z, P8_16D, NP8_16D); |
| 743 | q = neval (z, Q8_16N, NQ8_16N) / deval (z, Q8_16D, NQ8_16D); |
| 744 | } |
| 745 | } |
| 746 | else if (xinv <= 0.1875) |
| 747 | { |
| 748 | p = neval (z, P5_8N, NP5_8N) / deval (z, P5_8D, NP5_8D); |
| 749 | q = neval (z, Q5_8N, NQ5_8N) / deval (z, Q5_8D, NQ5_8D); |
| 750 | } |
| 751 | else |
| 752 | { |
| 753 | p = neval (z, P4_5N, NP4_5N) / deval (z, P4_5D, NP4_5D); |
| 754 | q = neval (z, Q4_5N, NQ4_5N) / deval (z, Q4_5D, NQ4_5D); |
| 755 | } |
| 756 | } /* .25 */ |
| 757 | else /* if (xinv <= 0.5) */ |
| 758 | { |
| 759 | if (xinv <= 0.375) |
| 760 | { |
| 761 | if (xinv <= 0.3125) |
| 762 | { |
| 763 | p = neval (z, P3r2_4N, NP3r2_4N) / deval (z, P3r2_4D, NP3r2_4D); |
| 764 | q = neval (z, Q3r2_4N, NQ3r2_4N) / deval (z, Q3r2_4D, NQ3r2_4D); |
| 765 | } |
| 766 | else |
| 767 | { |
| 768 | p = neval (z, P2r7_3r2N, NP2r7_3r2N) |
| 769 | / deval (z, P2r7_3r2D, NP2r7_3r2D); |
| 770 | q = neval (z, Q2r7_3r2N, NQ2r7_3r2N) |
| 771 | / deval (z, Q2r7_3r2D, NQ2r7_3r2D); |
| 772 | } |
| 773 | } |
| 774 | else if (xinv <= 0.4375) |
| 775 | { |
| 776 | p = neval (z, P2r3_2r7N, NP2r3_2r7N) |
| 777 | / deval (z, P2r3_2r7D, NP2r3_2r7D); |
| 778 | q = neval (z, Q2r3_2r7N, NQ2r3_2r7N) |
| 779 | / deval (z, Q2r3_2r7D, NQ2r3_2r7D); |
| 780 | } |
| 781 | else |
| 782 | { |
| 783 | p = neval (z, P2_2r3N, NP2_2r3N) / deval (z, P2_2r3D, NP2_2r3D); |
| 784 | q = neval (z, Q2_2r3N, NQ2_2r3N) / deval (z, Q2_2r3D, NQ2_2r3D); |
| 785 | } |
| 786 | } |
| 787 | p = 1 + z * p; |
| 788 | q = z * xinv * q; |
| 789 | q = q - L(0.125) * xinv; |
| 790 | z = ONEOSQPI * (p * cc - q * ss) / sqrtl (xx); |
| 791 | return z; |
| 792 | } |
| 793 | libm_alias_finite (__ieee754_j0l, __j0l) |
| 794 | |
| 795 | |
| 796 | /* Y0(x) = 2/pi * log(x) * J0(x) + R(x^2) |
| 797 | Peak absolute error 1.7e-36 (relative where Y0 > 1) |
| 798 | 0 <= x <= 2 */ |
| 799 | #define NY0_2N 7 |
| 800 | static const _Float128 Y0_2N[NY0_2N + 1] = { |
| 801 | L(-1.062023609591350692692296993537002558155E19), |
| 802 | L(2.542000883190248639104127452714966858866E19), |
| 803 | L(-1.984190771278515324281415820316054696545E18), |
| 804 | L(4.982586044371592942465373274440222033891E16), |
| 805 | L(-5.529326354780295177243773419090123407550E14), |
| 806 | L(3.013431465522152289279088265336861140391E12), |
| 807 | L(-7.959436160727126750732203098982718347785E9), |
| 808 | L(8.230845651379566339707130644134372793322E6), |
| 809 | }; |
| 810 | #define NY0_2D 7 |
| 811 | static const _Float128 Y0_2D[NY0_2D + 1] = { |
| 812 | L(1.438972634353286978700329883122253752192E20), |
| 813 | L(1.856409101981569254247700169486907405500E18), |
| 814 | L(1.219693352678218589553725579802986255614E16), |
| 815 | L(5.389428943282838648918475915779958097958E13), |
| 816 | L(1.774125762108874864433872173544743051653E11), |
| 817 | L(4.522104832545149534808218252434693007036E8), |
| 818 | L(8.872187401232943927082914504125234454930E5), |
| 819 | L(1.251945613186787532055610876304669413955E3), |
| 820 | /* 1.000000000000000000000000000000000000000E0 */ |
| 821 | }; |
| 822 | |
| 823 | static const _Float128 U0 = L(-7.3804295108687225274343927948483016310862e-02); |
| 824 | |
| 825 | /* Bessel function of the second kind, order zero. */ |
| 826 | |
| 827 | _Float128 |
| 828 | __ieee754_y0l(_Float128 x) |
| 829 | { |
| 830 | _Float128 xx, xinv, z, p, q, c, s, cc, ss; |
| 831 | |
| 832 | if (! isfinite (x)) |
| 833 | return 1 / (x + x * x); |
| 834 | if (x <= 0) |
| 835 | { |
| 836 | if (x < 0) |
| 837 | return (zero / (zero * x)); |
| 838 | return -1 / zero; /* -inf and divide by zero exception. */ |
| 839 | } |
| 840 | xx = fabsl (x); |
| 841 | if (xx <= 0x1p-57) |
| 842 | return U0 + TWOOPI * __ieee754_logl (x); |
| 843 | if (xx <= 2) |
| 844 | { |
| 845 | /* 0 <= x <= 2 */ |
| 846 | z = xx * xx; |
| 847 | p = neval (z, Y0_2N, NY0_2N) / deval (z, Y0_2D, NY0_2D); |
| 848 | p = TWOOPI * __ieee754_logl (x) * __ieee754_j0l (x) + p; |
| 849 | return p; |
| 850 | } |
| 851 | |
| 852 | /* X = x - pi/4 |
| 853 | cos(X) = cos(x) cos(pi/4) + sin(x) sin(pi/4) |
| 854 | = 1/sqrt(2) * (cos(x) + sin(x)) |
| 855 | sin(X) = sin(x) cos(pi/4) - cos(x) sin(pi/4) |
| 856 | = 1/sqrt(2) * (sin(x) - cos(x)) |
| 857 | sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x)) |
| 858 | cf. Fdlibm. */ |
| 859 | __sincosl (x, &s, &c); |
| 860 | ss = s - c; |
| 861 | cc = s + c; |
| 862 | if (xx <= LDBL_MAX / 2) |
| 863 | { |
| 864 | z = -__cosl (x + x); |
| 865 | if ((s * c) < 0) |
| 866 | cc = z / ss; |
| 867 | else |
| 868 | ss = z / cc; |
| 869 | } |
| 870 | |
| 871 | if (xx > L(0x1p256)) |
| 872 | return ONEOSQPI * ss / sqrtl (x); |
| 873 | |
| 874 | xinv = 1 / xx; |
| 875 | z = xinv * xinv; |
| 876 | if (xinv <= 0.25) |
| 877 | { |
| 878 | if (xinv <= 0.125) |
| 879 | { |
| 880 | if (xinv <= 0.0625) |
| 881 | { |
| 882 | p = neval (z, P16_IN, NP16_IN) / deval (z, P16_ID, NP16_ID); |
| 883 | q = neval (z, Q16_IN, NQ16_IN) / deval (z, Q16_ID, NQ16_ID); |
| 884 | } |
| 885 | else |
| 886 | { |
| 887 | p = neval (z, P8_16N, NP8_16N) / deval (z, P8_16D, NP8_16D); |
| 888 | q = neval (z, Q8_16N, NQ8_16N) / deval (z, Q8_16D, NQ8_16D); |
| 889 | } |
| 890 | } |
| 891 | else if (xinv <= 0.1875) |
| 892 | { |
| 893 | p = neval (z, P5_8N, NP5_8N) / deval (z, P5_8D, NP5_8D); |
| 894 | q = neval (z, Q5_8N, NQ5_8N) / deval (z, Q5_8D, NQ5_8D); |
| 895 | } |
| 896 | else |
| 897 | { |
| 898 | p = neval (z, P4_5N, NP4_5N) / deval (z, P4_5D, NP4_5D); |
| 899 | q = neval (z, Q4_5N, NQ4_5N) / deval (z, Q4_5D, NQ4_5D); |
| 900 | } |
| 901 | } /* .25 */ |
| 902 | else /* if (xinv <= 0.5) */ |
| 903 | { |
| 904 | if (xinv <= 0.375) |
| 905 | { |
| 906 | if (xinv <= 0.3125) |
| 907 | { |
| 908 | p = neval (z, P3r2_4N, NP3r2_4N) / deval (z, P3r2_4D, NP3r2_4D); |
| 909 | q = neval (z, Q3r2_4N, NQ3r2_4N) / deval (z, Q3r2_4D, NQ3r2_4D); |
| 910 | } |
| 911 | else |
| 912 | { |
| 913 | p = neval (z, P2r7_3r2N, NP2r7_3r2N) |
| 914 | / deval (z, P2r7_3r2D, NP2r7_3r2D); |
| 915 | q = neval (z, Q2r7_3r2N, NQ2r7_3r2N) |
| 916 | / deval (z, Q2r7_3r2D, NQ2r7_3r2D); |
| 917 | } |
| 918 | } |
| 919 | else if (xinv <= 0.4375) |
| 920 | { |
| 921 | p = neval (z, P2r3_2r7N, NP2r3_2r7N) |
| 922 | / deval (z, P2r3_2r7D, NP2r3_2r7D); |
| 923 | q = neval (z, Q2r3_2r7N, NQ2r3_2r7N) |
| 924 | / deval (z, Q2r3_2r7D, NQ2r3_2r7D); |
| 925 | } |
| 926 | else |
| 927 | { |
| 928 | p = neval (z, P2_2r3N, NP2_2r3N) / deval (z, P2_2r3D, NP2_2r3D); |
| 929 | q = neval (z, Q2_2r3N, NQ2_2r3N) / deval (z, Q2_2r3D, NQ2_2r3D); |
| 930 | } |
| 931 | } |
| 932 | p = 1 + z * p; |
| 933 | q = z * xinv * q; |
| 934 | q = q - L(0.125) * xinv; |
| 935 | z = ONEOSQPI * (p * ss + q * cc) / sqrtl (x); |
| 936 | return z; |
| 937 | } |
| 938 | libm_alias_finite (__ieee754_y0l, __y0l) |
| 939 | |