aboutsummaryrefslogtreecommitdiff
path: root/lib/msun/ld80/b_logl.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/msun/ld80/b_logl.c')
-rw-r--r--lib/msun/ld80/b_logl.c375
1 files changed, 375 insertions, 0 deletions
diff --git a/lib/msun/ld80/b_logl.c b/lib/msun/ld80/b_logl.c
new file mode 100644
index 000000000000..b11eacbe17a1
--- /dev/null
+++ b/lib/msun/ld80/b_logl.c
@@ -0,0 +1,375 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1992, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * See bsdsrc/b_log.c for implementation details.
+ *
+ * bsdrc/b_log.c converted to long double by Steven G. Kargl.
+ */
+
+#define N 128
+
+/*
+ * Coefficients in the polynomial approximation of log(1+f/F).
+ * Domain of x is [0,1./256] with 2**(-84.48) precision.
+ */
+static const union IEEEl2bits
+ a1u = LD80C(0xaaaaaaaaaaaaaaab, -4, 8.33333333333333333356e-02L),
+ a2u = LD80C(0xcccccccccccccd29, -7, 1.25000000000000000781e-02L),
+ a3u = LD80C(0x9249249241ed3764, -9, 2.23214285711721994134e-03L),
+ a4u = LD80C(0xe38e959e1e7e01cf, -12, 4.34030476540000360640e-04L);
+#define A1 (a1u.e)
+#define A2 (a2u.e)
+#define A3 (a3u.e)
+#define A4 (a4u.e)
+
+/*
+ * Table of log(Fj) = logF_head[j] + logF_tail[j], for Fj = 1+j/128.
+ * Used for generation of extend precision logarithms.
+ * The constant 35184372088832 is 2^45, so the divide is exact.
+ * It ensures correct reading of logF_head, even for inaccurate
+ * decimal-to-binary conversion routines. (Everybody gets the
+ * right answer for integers less than 2^53.)
+ * Values for log(F) were generated using error < 10^-57 absolute
+ * with the bc -l package.
+ */
+
+static double logF_head[N+1] = {
+ 0.,
+ .007782140442060381246,
+ .015504186535963526694,
+ .023167059281547608406,
+ .030771658666765233647,
+ .038318864302141264488,
+ .045809536031242714670,
+ .053244514518837604555,
+ .060624621816486978786,
+ .067950661908525944454,
+ .075223421237524235039,
+ .082443669210988446138,
+ .089612158689760690322,
+ .096729626458454731618,
+ .103796793681567578460,
+ .110814366340264314203,
+ .117783035656430001836,
+ .124703478501032805070,
+ .131576357788617315236,
+ .138402322859292326029,
+ .145182009844575077295,
+ .151916042025732167530,
+ .158605030176659056451,
+ .165249572895390883786,
+ .171850256926518341060,
+ .178407657472689606947,
+ .184922338493834104156,
+ .191394852999565046047,
+ .197825743329758552135,
+ .204215541428766300668,
+ .210564769107350002741,
+ .216873938300523150246,
+ .223143551314024080056,
+ .229374101064877322642,
+ .235566071312860003672,
+ .241719936886966024758,
+ .247836163904594286577,
+ .253915209980732470285,
+ .259957524436686071567,
+ .265963548496984003577,
+ .271933715484010463114,
+ .277868451003087102435,
+ .283768173130738432519,
+ .289633292582948342896,
+ .295464212893421063199,
+ .301261330578199704177,
+ .307025035294827830512,
+ .312755710004239517729,
+ .318453731118097493890,
+ .324119468654316733591,
+ .329753286372579168528,
+ .335355541920762334484,
+ .340926586970454081892,
+ .346466767346100823488,
+ .351976423156884266063,
+ .357455888922231679316,
+ .362905493689140712376,
+ .368325561158599157352,
+ .373716409793814818840,
+ .379078352934811846353,
+ .384411698910298582632,
+ .389716751140440464951,
+ .394993808240542421117,
+ .400243164127459749579,
+ .405465108107819105498,
+ .410659924985338875558,
+ .415827895143593195825,
+ .420969294644237379543,
+ .426084395310681429691,
+ .431173464818130014464,
+ .436236766774527495726,
+ .441274560805140936281,
+ .446287102628048160113,
+ .451274644139630254358,
+ .456237433481874177232,
+ .461175715122408291790,
+ .466089729924533457960,
+ .470979715219073113985,
+ .475845904869856894947,
+ .480688529345570714212,
+ .485507815781602403149,
+ .490303988045525329653,
+ .495077266798034543171,
+ .499827869556611403822,
+ .504556010751912253908,
+ .509261901790523552335,
+ .513945751101346104405,
+ .518607764208354637958,
+ .523248143765158602036,
+ .527867089620485785417,
+ .532464798869114019908,
+ .537041465897345915436,
+ .541597282432121573947,
+ .546132437597407260909,
+ .550647117952394182793,
+ .555141507540611200965,
+ .559615787935399566777,
+ .564070138285387656651,
+ .568504735352689749561,
+ .572919753562018740922,
+ .577315365035246941260,
+ .581691739635061821900,
+ .586049045003164792433,
+ .590387446602107957005,
+ .594707107746216934174,
+ .599008189645246602594,
+ .603290851438941899687,
+ .607555250224322662688,
+ .611801541106615331955,
+ .616029877215623855590,
+ .620240409751204424537,
+ .624433288012369303032,
+ .628608659422752680256,
+ .632766669570628437213,
+ .636907462236194987781,
+ .641031179420679109171,
+ .645137961373620782978,
+ .649227946625615004450,
+ .653301272011958644725,
+ .657358072709030238911,
+ .661398482245203922502,
+ .665422632544505177065,
+ .669430653942981734871,
+ .673422675212350441142,
+ .677398823590920073911,
+ .681359224807238206267,
+ .685304003098281100392,
+ .689233281238557538017,
+ .693147180560117703862
+};
+
+static double logF_tail[N+1] = {
+ 0.,
+ -.00000000000000543229938420049,
+ .00000000000000172745674997061,
+ -.00000000000001323017818229233,
+ -.00000000000001154527628289872,
+ -.00000000000000466529469958300,
+ .00000000000005148849572685810,
+ -.00000000000002532168943117445,
+ -.00000000000005213620639136504,
+ -.00000000000001819506003016881,
+ .00000000000006329065958724544,
+ .00000000000008614512936087814,
+ -.00000000000007355770219435028,
+ .00000000000009638067658552277,
+ .00000000000007598636597194141,
+ .00000000000002579999128306990,
+ -.00000000000004654729747598444,
+ -.00000000000007556920687451336,
+ .00000000000010195735223708472,
+ -.00000000000017319034406422306,
+ -.00000000000007718001336828098,
+ .00000000000010980754099855238,
+ -.00000000000002047235780046195,
+ -.00000000000008372091099235912,
+ .00000000000014088127937111135,
+ .00000000000012869017157588257,
+ .00000000000017788850778198106,
+ .00000000000006440856150696891,
+ .00000000000016132822667240822,
+ -.00000000000007540916511956188,
+ -.00000000000000036507188831790,
+ .00000000000009120937249914984,
+ .00000000000018567570959796010,
+ -.00000000000003149265065191483,
+ -.00000000000009309459495196889,
+ .00000000000017914338601329117,
+ -.00000000000001302979717330866,
+ .00000000000023097385217586939,
+ .00000000000023999540484211737,
+ .00000000000015393776174455408,
+ -.00000000000036870428315837678,
+ .00000000000036920375082080089,
+ -.00000000000009383417223663699,
+ .00000000000009433398189512690,
+ .00000000000041481318704258568,
+ -.00000000000003792316480209314,
+ .00000000000008403156304792424,
+ -.00000000000034262934348285429,
+ .00000000000043712191957429145,
+ -.00000000000010475750058776541,
+ -.00000000000011118671389559323,
+ .00000000000037549577257259853,
+ .00000000000013912841212197565,
+ .00000000000010775743037572640,
+ .00000000000029391859187648000,
+ -.00000000000042790509060060774,
+ .00000000000022774076114039555,
+ .00000000000010849569622967912,
+ -.00000000000023073801945705758,
+ .00000000000015761203773969435,
+ .00000000000003345710269544082,
+ -.00000000000041525158063436123,
+ .00000000000032655698896907146,
+ -.00000000000044704265010452446,
+ .00000000000034527647952039772,
+ -.00000000000007048962392109746,
+ .00000000000011776978751369214,
+ -.00000000000010774341461609578,
+ .00000000000021863343293215910,
+ .00000000000024132639491333131,
+ .00000000000039057462209830700,
+ -.00000000000026570679203560751,
+ .00000000000037135141919592021,
+ -.00000000000017166921336082431,
+ -.00000000000028658285157914353,
+ -.00000000000023812542263446809,
+ .00000000000006576659768580062,
+ -.00000000000028210143846181267,
+ .00000000000010701931762114254,
+ .00000000000018119346366441110,
+ .00000000000009840465278232627,
+ -.00000000000033149150282752542,
+ -.00000000000018302857356041668,
+ -.00000000000016207400156744949,
+ .00000000000048303314949553201,
+ -.00000000000071560553172382115,
+ .00000000000088821239518571855,
+ -.00000000000030900580513238244,
+ -.00000000000061076551972851496,
+ .00000000000035659969663347830,
+ .00000000000035782396591276383,
+ -.00000000000046226087001544578,
+ .00000000000062279762917225156,
+ .00000000000072838947272065741,
+ .00000000000026809646615211673,
+ -.00000000000010960825046059278,
+ .00000000000002311949383800537,
+ -.00000000000058469058005299247,
+ -.00000000000002103748251144494,
+ -.00000000000023323182945587408,
+ -.00000000000042333694288141916,
+ -.00000000000043933937969737844,
+ .00000000000041341647073835565,
+ .00000000000006841763641591466,
+ .00000000000047585534004430641,
+ .00000000000083679678674757695,
+ -.00000000000085763734646658640,
+ .00000000000021913281229340092,
+ -.00000000000062242842536431148,
+ -.00000000000010983594325438430,
+ .00000000000065310431377633651,
+ -.00000000000047580199021710769,
+ -.00000000000037854251265457040,
+ .00000000000040939233218678664,
+ .00000000000087424383914858291,
+ .00000000000025218188456842882,
+ -.00000000000003608131360422557,
+ -.00000000000050518555924280902,
+ .00000000000078699403323355317,
+ -.00000000000067020876961949060,
+ .00000000000016108575753932458,
+ .00000000000058527188436251509,
+ -.00000000000035246757297904791,
+ -.00000000000018372084495629058,
+ .00000000000088606689813494916,
+ .00000000000066486268071468700,
+ .00000000000063831615170646519,
+ .00000000000025144230728376072,
+ -.00000000000017239444525614834
+};
+/*
+ * Extra precision variant, returning struct {double a, b;};
+ * log(x) = a + b to 63 bits, with 'a' rounded to 24 bits.
+ */
+static struct Double
+__log__D(long double x)
+{
+ int m, j;
+ long double F, f, g, q, u, v, u1, u2;
+ struct Double r;
+
+ /*
+ * Argument reduction: 1 <= g < 2; x/2^m = g;
+ * y = F*(1 + f/F) for |f| <= 2^-8
+ */
+ g = frexpl(x, &m);
+ g *= 2;
+ m--;
+ if (m == DBL_MIN_EXP - 1) {
+ j = ilogbl(g);
+ m += j;
+ g = ldexpl(g, -j);
+ }
+ j = N * (g - 1) + 0.5L;
+ F = (1.L / N) * j + 1;
+ f = g - F;
+
+ g = 1 / (2 * F + f);
+ u = 2 * f * g;
+ v = u * u;
+ q = u * v * (A1 + v * (A2 + v * (A3 + v * A4)));
+ if (m | j) {
+ u1 = u + 513;
+ u1 -= 513;
+ } else {
+ u1 = (float)u;
+ }
+ u2 = (2 * (f - F * u1) - u1 * f) * g;
+
+ u1 += m * (long double)logF_head[N] + logF_head[j];
+
+ u2 += logF_tail[j];
+ u2 += q;
+ u2 += logF_tail[N] * m;
+ r.a = (float)(u1 + u2); /* Only difference is here. */
+ r.b = (u1 - r.a) + u2;
+ return (r);
+}