diff options
Diffstat (limited to 'usr/src/lib/libmvec/common/__vexpf.c')
-rw-r--r-- | usr/src/lib/libmvec/common/__vexpf.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/usr/src/lib/libmvec/common/__vexpf.c b/usr/src/lib/libmvec/common/__vexpf.c new file mode 100644 index 0000000000..9e340bba68 --- /dev/null +++ b/usr/src/lib/libmvec/common/__vexpf.c @@ -0,0 +1,351 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ + +/* + * Copyright 2011 Nexenta Systems, Inc. All rights reserved. + */ +/* + * Copyright 2006 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#ifdef __RESTRICT +#define restrict _Restrict +#else +#define restrict +#endif + +/* float expf(float x) + * + * Method : + * 1. Special cases: + * for x > 88.722839355...(0x42B17218) => Inf + overflow; + * for x < -103.97207642..(0xc2CFF1B4) => 0 + underflow; + * for x = Inf => Inf; + * for x = -Inf => 0; + * for x = +-NaN => QNaN. + * 2. Computes exponential from: + * exp(x) = 2**a * 2**(k/256) * 2**(y/256) + * Where: + * a = int ( 256 * log2(e) * x ) >> 8; + * k = int ( 256 * log2(e) * x ) & 0xFF; + * y = frac ( 256 * x * log2(e)). + * Note that: + * k = 0, 1, ..., 255; + * y = (-1, 1). + * Then: + * 2**(k/256) is looked up in a table of 2**0, 2**1/256, ... + * 2**(y/256) is computed using approximation: + * 2**(y/256) = a0 + a1 * y + a2 * y**2 + * Multiplication by 2**a is done by adding "a" to + * the biased exponent. + * Accuracy: + * The maximum relative error for the approximating + * polynomial is 2**(-29.18). All calculations are of + * double precision. + * Maximum error observed: less than 0.528 ulp for the whole + * float type range. + * + * NOTE: This implementation has been modified for SPARC to deliver + * zero instead of a subnormal result whenever the argument is less + * than log(2^-126). Therefore the worst case relative error is 1. + */ + +static const double __TBL_exp2f[] = { + /* 2^(i/256) - (((i & 0xff) << 44), i = [0, 255] */ +1.000000000000000000e+00, 9.994025125251012609e-01, 9.988087005564013632e-01, +9.982185740592087742e-01, 9.976321430258502376e-01, 9.970494174757447148e-01, +9.964704074554765478e-01, 9.958951230388689568e-01, 9.953235743270583136e-01, +9.947557714485678604e-01, 9.941917245593818730e-01, 9.936314438430204898e-01, +9.930749395106142074e-01, 9.925222218009785990e-01, 9.919733009806893653e-01, +9.914281873441580517e-01, 9.908868912137068774e-01, 9.903494229396448967e-01, +9.898157929003436051e-01, 9.892860115023132117e-01, 9.887600891802785785e-01, +9.882380363972563808e-01, 9.877198636446310465e-01, 9.872055814422322495e-01, +9.866952003384118486e-01, 9.861887309101209365e-01, 9.856861837629877776e-01, +9.851875695313955239e-01, 9.846928988785599302e-01, 9.842021824966076249e-01, +9.837154311066546031e-01, 9.832326554588848300e-01, 9.827538663326288448e-01, +9.822790745364429199e-01, 9.818082909081884413e-01, 9.813415263151109569e-01, +9.808787916539204454e-01, 9.804200978508705866e-01, 9.799654558618393629e-01, +9.795148766724087741e-01, 9.790683712979462161e-01, 9.786259507836846394e-01, +9.781876262048033732e-01, 9.777534086665099489e-01, 9.773233093041209241e-01, +9.768973392831440394e-01, 9.764755097993595978e-01, 9.760578320789027318e-01, +9.756443173783457823e-01, 9.752349769847807881e-01, 9.748298222159020865e-01, +9.744288644200894689e-01, 9.740321149764913367e-01, 9.736395852951079677e-01, +9.732512868168755604e-01, 9.728672310137493895e-01, 9.724874293887887378e-01, +9.721118934762408292e-01, 9.717406348416250950e-01, 9.713736650818186602e-01, +9.710109958251406104e-01, 9.706526387314379223e-01, 9.702986054921705072e-01, +9.699489078304969203e-01, 9.696035575013605134e-01, 9.692625662915755891e-01, +9.689259460199136642e-01, 9.685937085371902899e-01, 9.682658657263515378e-01, +9.679424295025619296e-01, 9.676234118132908124e-01, 9.673088246384006217e-01, +9.669986799902344776e-01, 9.666929899137042259e-01, 9.663917664863788115e-01, +9.660950218185727634e-01, 9.658027680534350123e-01, 9.655150173670379310e-01, +9.652317819684667066e-01, 9.649530740999082701e-01, 9.646789060367420010e-01, +9.644092900876289898e-01, 9.641442385946024096e-01, 9.638837639331581109e-01, +9.636278785123455481e-01, 9.633765947748582636e-01, 9.631299251971253694e-01, +9.628878822894031408e-01, 9.626504785958666099e-01, 9.624177266947013809e-01, +9.621896391981960006e-01, 9.619662287528346623e-01, 9.617475080393891318e-01, +9.615334897730127839e-01, 9.613241867033328614e-01, 9.611196116145447332e-01, +9.609197773255048203e-01, 9.607246966898252971e-01, 9.605343825959679060e-01, +9.603488479673386591e-01, 9.601681057623822069e-01, 9.599921689746773179e-01, +9.598210506330320246e-01, 9.596547638015787696e-01, 9.594933215798706616e-01, +9.593367371029771773e-01, 9.591850235415807502e-01, 9.590381941020729162e-01, +9.588962620266514580e-01, 9.587592405934176609e-01, 9.586271431164729018e-01, +9.584999829460172371e-01, 9.583777734684463256e-01, 9.582605281064505709e-01, +9.581482603191123770e-01, 9.580409836020059577e-01, 9.579387114872952580e-01, +9.578414575438342071e-01, 9.577492353772650846e-01, 9.576620586301189952e-01, +9.575799409819160113e-01, 9.575028961492645374e-01, 9.574309378859631181e-01, +9.573640799831001358e-01, 9.573023362691556182e-01, 9.572457206101023797e-01, +9.571942469095077177e-01, 9.571479291086353314e-01, 9.571067811865475727e-01, +9.570708171602075875e-01, 9.570400510845827879e-01, 9.570144970527471040e-01, +9.569941691959850116e-01, 9.569790816838944503e-01, 9.569692487244911838e-01, +9.569646845643128286e-01, 9.569654034885233251e-01, 9.569714198210175216e-01, +9.569827479245263113e-01, 9.569994022007218826e-01, 9.570213970903235223e-01, +9.570487470732028656e-01, 9.570814666684909211e-01, 9.571195704346837640e-01, +9.571630729697496731e-01, 9.572119889112359337e-01, 9.572663329363761964e-01, +9.573261197621985019e-01, 9.573913641456324175e-01, 9.574620808836177277e-01, +9.575382848132127922e-01, 9.576199908117032367e-01, 9.577072137967114207e-01, +9.577999687263049067e-01, 9.578982705991073709e-01, 9.580021344544072948e-01, +9.581115753722692086e-01, 9.582266084736434930e-01, 9.583472489204779565e-01, +9.584735119158284133e-01, 9.586054127039703721e-01, 9.587429665705107240e-01, +9.588861888424999869e-01, 9.590350948885443261e-01, 9.591897001189184646e-01, +9.593500199856788146e-01, 9.595160699827764983e-01, 9.596878656461707013e-01, +9.598654225539432483e-01, 9.600487563264122892e-01, 9.602378826262468747e-01, +9.604328171585819751e-01, 9.606335756711334994e-01, 9.608401739543135367e-01, +9.610526278413467072e-01, 9.612709532083855146e-01, 9.614951659746271417e-01, +9.617252821024303566e-01, 9.619613175974318642e-01, 9.622032885086644338e-01, +9.624512109286739170e-01, 9.627051009936374859e-01, 9.629649748834822054e-01, +9.632308488220031606e-01, 9.635027390769824729e-01, 9.637806619603088709e-01, +9.640646338280971506e-01, 9.643546710808080791e-01, 9.646507901633681881e-01, +9.649530075652912320e-01, 9.652613398207983142e-01, 9.655758035089392344e-01, +9.658964152537145020e-01, 9.662231917241966839e-01, 9.665561496346526393e-01, +9.668953057446663113e-01, 9.672406768592617388e-01, 9.675922798290256255e-01, +9.679501315502314629e-01, 9.683142489649629869e-01, 9.686846490612389671e-01, +9.690613488731369962e-01, 9.694443654809188349e-01, 9.698337160111555333e-01, +9.702294176368531087e-01, 9.706314875775782225e-01, 9.710399430995845238e-01, +9.714548015159391037e-01, 9.718760801866497268e-01, 9.723037965187919518e-01, +9.727379679666363632e-01, 9.731786120317773570e-01, 9.736257462632605941e-01, +9.740793882577122309e-01, 9.745395556594674824e-01, 9.750062661607005188e-01, +9.754795375015535841e-01, 9.759593874702675587e-01, 9.764458339033119660e-01, +9.769388946855159794e-01, 9.774385877501994280e-01, 9.779449310793042471e-01, +9.784579427035267063e-01, 9.789776407024486371e-01, 9.795040432046712153e-01, +9.800371683879468554e-01, 9.805770344793129922e-01, 9.811236597552254191e-01, +9.816770625416927354e-01, 9.822372612144102400e-01, 9.828042741988944897e-01, +9.833781199706193021e-01, 9.839588170551499813e-01, 9.845463840282800971e-01, +9.851408395161672660e-01, 9.857422021954695968e-01, 9.863504907934828037e-01, +9.869657240882776517e-01, 9.875879209088370692e-01, 9.882171001351949258e-01, +9.888532806985737000e-01, 9.894964815815237014e-01, 9.901467218180625141e-01, +9.908040204938135531e-01, 9.914683967461471736e-01, 9.921398697643202258e-01, +9.928184587896166091e-01, 9.935041831154891590e-01, 9.941970620877000897e-01, +9.948971151044636585e-01, 9.956043616165879406e-01, 9.963188211276171602e-01, +9.970405131939754639e-01, 9.977694574251096959e-01, 9.985056734836331715e-01, +9.992491810854701173e-01 +}; + +static const double + K256ONLN2 = 369.3299304675746271, + KA2 = 3.66556671660783833261e-06, + KA1 = 2.70760782821392980564e-03, + KA0 = 1.0; + +static const float extreme[2] = { 1.0e30f, 1.0e-30f }; + +#define PROCESS(N) \ + x##N *= K256ONLN2; \ + k##N = (int) x##N; \ + x##N -= (double) k##N; \ + x##N = (KA2 * x##N + KA1) * x##N + KA0; \ + lres##N = ((long long *)__TBL_exp2f)[k##N & 0xff]; \ + lres##N += (long long)k##N << 44; \ + *y = (float) (x##N * *(double *)&lres##N); \ + y += stridey + +#ifdef __sparc + +#define PREPROCESS(N, index, label) \ + xi = *(int *)x; \ + ax = xi & ~0x80000000; \ + fx = *x; \ + x += stridex; \ + if (ax >= 0x42aeac50) /* log(2^126) = 87.3365... */ \ + { \ + sign = (unsigned)xi >> 31; \ + if (ax >= 0x7f800000) /* |x| = inf or nan */ \ + { \ + if (ax > 0x7f800000) /* nan */ \ + { \ + y[index] = fx * fx; \ + goto label; \ + } \ + y[index] = (sign) ? 0.0f : fx; \ + goto label; \ + } \ + if (sign || ax > 0x42b17218) { \ + fx = extreme[sign]; \ + y[index] = fx * fx; \ + goto label; \ + } \ + } \ + x##N = fx + +#else + +#define PREPROCESS(N, index, label) \ + xi = *(int *)x; \ + ax = xi & ~0x80000000; \ + fx = *x; \ + x += stridex; \ + if (ax > 0x42cff1b4) /* 103.972076f */ \ + { \ + sign = (unsigned)xi >> 31; \ + if (ax >= 0x7f800000) /* |x| = inf or nan */ \ + { \ + if (ax > 0x7f800000) /* nan */ \ + { \ + y[index] = fx * fx; \ + goto label; \ + } \ + y[index] = (sign) ? 0.0f : fx; \ + goto label; \ + } \ + fx = extreme[sign]; \ + y[index] = fx * fx; \ + goto label; \ + } \ + x##N = fx + +#endif + +void +__vexpf(int n, float * restrict x, int stridex, float * restrict y, + int stridey) +{ + double x0, x1, x2, x3, x4; + double res0, res1, res2, res3, res4; + float fx; + long long lres0, lres1, lres2, lres3, lres4; + int k0, k1, k2, k3, k4; + int xi, ax, sign; + + y -= stridey; + + for (; ;) + { +begin: + if (--n < 0) + break; + y += stridey; + + PREPROCESS(0, 0, begin); + + if (--n < 0) + goto process1; + + PREPROCESS(1, stridey, process1); + + if (--n < 0) + goto process2; + + PREPROCESS(2, stridey << 1, process2); + + if (--n < 0) + goto process3; + + PREPROCESS(3, (stridey << 1) + stridey, process3); + + if (--n < 0) + goto process4; + + PREPROCESS(4, (stridey << 2), process4); + + x0 *= K256ONLN2; + x1 *= K256ONLN2; + x2 *= K256ONLN2; + x3 *= K256ONLN2; + x4 *= K256ONLN2; + + k0 = (int)x0; + k1 = (int)x1; + k2 = (int)x2; + k3 = (int)x3; + k4 = (int)x4; + + x0 -= (double)k0; + x1 -= (double)k1; + x2 -= (double)k2; + x3 -= (double)k3; + x4 -= (double)k4; + + x0 = (KA2 * x0 + KA1) * x0 + KA0; + x1 = (KA2 * x1 + KA1) * x1 + KA0; + x2 = (KA2 * x2 + KA1) * x2 + KA0; + x3 = (KA2 * x3 + KA1) * x3 + KA0; + x4 = (KA2 * x4 + KA1) * x4 + KA0; + + lres0 = ((long long *)__TBL_exp2f)[k0 & 255]; + lres1 = ((long long *)__TBL_exp2f)[k1 & 255]; + lres2 = ((long long *)__TBL_exp2f)[k2 & 255]; + lres3 = ((long long *)__TBL_exp2f)[k3 & 255]; + lres4 = ((long long *)__TBL_exp2f)[k4 & 255]; + + lres0 += (long long)k0 << 44; + res0 = *(double *)&lres0; + lres1 += (long long)k1 << 44; + res1 = *(double *)&lres1; + lres2 += (long long)k2 << 44; + res2 = *(double *)&lres2; + lres3 += (long long)k3 << 44; + res3 = *(double *)&lres3; + lres4 += (long long)k4 << 44; + res4 = *(double *)&lres4; + + *y = (float)(res0 * x0); + y += stridey; + *y = (float)(res1 * x1); + y += stridey; + *y = (float)(res2 * x2); + y += stridey; + *y = (float)(res3 * x3); + y += stridey; + *y = (float)(res4 * x4); + continue; + +process1: + PROCESS(0); + continue; + +process2: + PROCESS(0); + PROCESS(1); + continue; + +process3: + PROCESS(0); + PROCESS(1); + PROCESS(2); + continue; + +process4: + PROCESS(0); + PROCESS(1); + PROCESS(2); + PROCESS(3); + } +} |