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author | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
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committer | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
commit | 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch) | |
tree | 4470480d904b65cf14ca524f96f79eca818c3eaf /sysdeps/ieee754/ldbl-128ibm/s_atanl.c | |
parent | 199fc19d3aaaf57944ef036e15904febe877fc93 (diff) | |
download | glibc-zack/build-layout-experiment.tar.gz glibc-zack/build-layout-experiment.tar.xz glibc-zack/build-layout-experiment.zip |
Prepare for radical source tree reorganization. zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control).
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_atanl.c')
-rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_atanl.c | 250 |
1 files changed, 0 insertions, 250 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_atanl.c b/sysdeps/ieee754/ldbl-128ibm/s_atanl.c deleted file mode 100644 index 0560d820ae..0000000000 --- a/sysdeps/ieee754/ldbl-128ibm/s_atanl.c +++ /dev/null @@ -1,250 +0,0 @@ -/* s_atanl.c - * - * Inverse circular tangent for 128-bit long double precision - * (arctangent) - * - * - * - * SYNOPSIS: - * - * long double x, y, atanl(); - * - * y = atanl( x ); - * - * - * - * DESCRIPTION: - * - * Returns radian angle between -pi/2 and +pi/2 whose tangent is x. - * - * The function uses a rational approximation of the form - * t + t^3 P(t^2)/Q(t^2), optimized for |t| < 0.09375. - * - * The argument is reduced using the identity - * arctan x - arctan u = arctan ((x-u)/(1 + ux)) - * and an 83-entry lookup table for arctan u, with u = 0, 1/8, ..., 10.25. - * Use of the table improves the execution speed of the routine. - * - * - * - * ACCURACY: - * - * Relative error: - * arithmetic domain # trials peak rms - * IEEE -19, 19 4e5 1.7e-34 5.4e-35 - * - * - * WARNING: - * - * This program uses integer operations on bit fields of floating-point - * numbers. It does not work with data structures other than the - * structure assumed. - * - */ - -/* Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov> - - This library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - This library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with this library; if not, see - <http://www.gnu.org/licenses/>. */ - - -#include <float.h> -#include <math.h> -#include <math_private.h> -#include <math_ldbl_opt.h> - -/* arctan(k/8), k = 0, ..., 82 */ -static const long double atantbl[84] = { - 0.0000000000000000000000000000000000000000E0L, - 1.2435499454676143503135484916387102557317E-1L, /* arctan(0.125) */ - 2.4497866312686415417208248121127581091414E-1L, - 3.5877067027057222039592006392646049977698E-1L, - 4.6364760900080611621425623146121440202854E-1L, - 5.5859931534356243597150821640166127034645E-1L, - 6.4350110879328438680280922871732263804151E-1L, - 7.1882999962162450541701415152590465395142E-1L, - 7.8539816339744830961566084581987572104929E-1L, - 8.4415398611317100251784414827164750652594E-1L, - 8.9605538457134395617480071802993782702458E-1L, - 9.4200004037946366473793717053459358607166E-1L, - 9.8279372324732906798571061101466601449688E-1L, - 1.0191413442663497346383429170230636487744E0L, - 1.0516502125483736674598673120862998296302E0L, - 1.0808390005411683108871567292171998202703E0L, - 1.1071487177940905030170654601785370400700E0L, - 1.1309537439791604464709335155363278047493E0L, - 1.1525719972156675180401498626127513797495E0L, - 1.1722738811284763866005949441337046149712E0L, - 1.1902899496825317329277337748293183376012E0L, - 1.2068173702852525303955115800565576303133E0L, - 1.2220253232109896370417417439225704908830E0L, - 1.2360594894780819419094519711090786987027E0L, - 1.2490457723982544258299170772810901230778E0L, - 1.2610933822524404193139408812473357720101E0L, - 1.2722973952087173412961937498224804940684E0L, - 1.2827408797442707473628852511364955306249E0L, - 1.2924966677897852679030914214070816845853E0L, - 1.3016288340091961438047858503666855921414E0L, - 1.3101939350475556342564376891719053122733E0L, - 1.3182420510168370498593302023271362531155E0L, - 1.3258176636680324650592392104284756311844E0L, - 1.3329603993374458675538498697331558093700E0L, - 1.3397056595989995393283037525895557411039E0L, - 1.3460851583802539310489409282517796256512E0L, - 1.3521273809209546571891479413898128509842E0L, - 1.3578579772154994751124898859640585287459E0L, - 1.3633001003596939542892985278250991189943E0L, - 1.3684746984165928776366381936948529556191E0L, - 1.3734007669450158608612719264449611486510E0L, - 1.3780955681325110444536609641291551522494E0L, - 1.3825748214901258580599674177685685125566E0L, - 1.3868528702577214543289381097042486034883E0L, - 1.3909428270024183486427686943836432060856E0L, - 1.3948567013423687823948122092044222644895E0L, - 1.3986055122719575950126700816114282335732E0L, - 1.4021993871854670105330304794336492676944E0L, - 1.4056476493802697809521934019958079881002E0L, - 1.4089588955564736949699075250792569287156E0L, - 1.4121410646084952153676136718584891599630E0L, - 1.4152014988178669079462550975833894394929E0L, - 1.4181469983996314594038603039700989523716E0L, - 1.4209838702219992566633046424614466661176E0L, - 1.4237179714064941189018190466107297503086E0L, - 1.4263547484202526397918060597281265695725E0L, - 1.4288992721907326964184700745371983590908E0L, - 1.4313562697035588982240194668401779312122E0L, - 1.4337301524847089866404719096698873648610E0L, - 1.4360250423171655234964275337155008780675E0L, - 1.4382447944982225979614042479354815855386E0L, - 1.4403930189057632173997301031392126865694E0L, - 1.4424730991091018200252920599377292525125E0L, - 1.4444882097316563655148453598508037025938E0L, - 1.4464413322481351841999668424758804165254E0L, - 1.4483352693775551917970437843145232637695E0L, - 1.4501726582147939000905940595923466567576E0L, - 1.4519559822271314199339700039142990228105E0L, - 1.4536875822280323362423034480994649820285E0L, - 1.4553696664279718992423082296859928222270E0L, - 1.4570043196511885530074841089245667532358E0L, - 1.4585935117976422128825857356750737658039E0L, - 1.4601391056210009726721818194296893361233E0L, - 1.4616428638860188872060496086383008594310E0L, - 1.4631064559620759326975975316301202111560E0L, - 1.4645314639038178118428450961503371619177E0L, - 1.4659193880646627234129855241049975398470E0L, - 1.4672716522843522691530527207287398276197E0L, - 1.4685896086876430842559640450619880951144E0L, - 1.4698745421276027686510391411132998919794E0L, - 1.4711276743037345918528755717617308518553E0L, - 1.4723501675822635384916444186631899205983E0L, - 1.4735431285433308455179928682541563973416E0L, /* arctan(10.25) */ - 1.5707963267948966192313216916397514420986E0L /* pi/2 */ -}; - - -/* arctan t = t + t^3 p(t^2) / q(t^2) - |t| <= 0.09375 - peak relative error 5.3e-37 */ - -static const long double - p0 = -4.283708356338736809269381409828726405572E1L, - p1 = -8.636132499244548540964557273544599863825E1L, - p2 = -5.713554848244551350855604111031839613216E1L, - p3 = -1.371405711877433266573835355036413750118E1L, - p4 = -8.638214309119210906997318946650189640184E-1L, - q0 = 1.285112506901621042780814422948906537959E2L, - q1 = 3.361907253914337187957855834229672347089E2L, - q2 = 3.180448303864130128268191635189365331680E2L, - q3 = 1.307244136980865800160844625025280344686E2L, - q4 = 2.173623741810414221251136181221172551416E1L; - /* q5 = 1.000000000000000000000000000000000000000E0 */ - - -long double -__atanl (long double x) -{ - int32_t k, sign, lx; - long double t, u, p, q; - double xhi; - - xhi = ldbl_high (x); - EXTRACT_WORDS (k, lx, xhi); - sign = k & 0x80000000; - - /* Check for IEEE special cases. */ - k &= 0x7fffffff; - if (k >= 0x7ff00000) - { - /* NaN. */ - if (((k - 0x7ff00000) | lx) != 0) - return (x + x); - - /* Infinity. */ - if (sign) - return -atantbl[83]; - else - return atantbl[83]; - } - - if (k <= 0x3c800000) /* |x| <= 2**-55. */ - { - math_check_force_underflow (x); - /* Raise inexact. */ - if (1e300L + x > 0.0) - return x; - } - - if (k >= 0x46c00000) /* |x| >= 2**109. */ - { - /* Saturate result to {-,+}pi/2. */ - if (sign) - return -atantbl[83]; - else - return atantbl[83]; - } - - if (sign) - x = -x; - - if (k >= 0x40248000) /* 10.25 */ - { - k = 83; - t = -1.0/x; - } - else - { - /* Index of nearest table element. - Roundoff to integer is asymmetrical to avoid cancellation when t < 0 - (cf. fdlibm). */ - k = 8.0 * x + 0.25; - u = 0.125 * k; - /* Small arctan argument. */ - t = (x - u) / (1.0 + x * u); - } - - /* Arctan of small argument t. */ - u = t * t; - p = ((((p4 * u) + p3) * u + p2) * u + p1) * u + p0; - q = ((((u + q4) * u + q3) * u + q2) * u + q1) * u + q0; - u = t * u * p / q + t; - - /* arctan x = arctan u + arctan t */ - u = atantbl[k] + u; - if (sign) - return (-u); - else - return u; -} - -long_double_symbol (libm, __atanl, atanl); |