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).

1 files changed, 282 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/ieee754/ldbl-128/e_logl.c b/REORG.TODO/sysdeps/ieee754/ldbl-128/e_logl.c
new file mode 100644
index 0000000000..8672047e43
--- /dev/null
+++ b/REORG.TODO/sysdeps/ieee754/ldbl-128/e_logl.c
@@ -0,0 +1,282 @@
+/*							logll.c
+ *
+ * Natural logarithm for 128-bit long double precision.
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * long double x, y, logl();
+ *
+ * y = logl( x );
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * Returns the base e (2.718...) logarithm of x.
+ *
+ * The argument is separated into its exponent and fractional
+ * parts.  Use of a lookup table increases the speed of the routine.
+ * The program uses logarithms tabulated at intervals of 1/128 to
+ * cover the domain from approximately 0.7 to 1.4.
+ *
+ * On the interval [-1/128, +1/128] the logarithm of 1+x is approximated by
+ *     log(1+x) = x - 0.5 x^2 + x^3 P(x) .
+ *
+ *
+ *
+ * ACCURACY:
+ *
+ *                      Relative error:
+ * arithmetic   domain     # trials      peak         rms
+ *    IEEE   0.875, 1.125   100000      1.2e-34    4.1e-35
+ *    IEEE   0.125, 8       100000      1.2e-34    4.1e-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 <math.h>
+#include <math_private.h>
+
+/* log(1+x) = x - .5 x^2 + x^3 l(x)
+   -.0078125 <= x <= +.0078125
+   peak relative error 1.2e-37 */
+static const _Float128
+l3 =   L(3.333333333333333333333333333333336096926E-1),
+l4 =  L(-2.499999999999999999999999999486853077002E-1),
+l5 =   L(1.999999999999999999999999998515277861905E-1),
+l6 =  L(-1.666666666666666666666798448356171665678E-1),
+l7 =   L(1.428571428571428571428808945895490721564E-1),
+l8 =  L(-1.249999999999999987884655626377588149000E-1),
+l9 =   L(1.111111111111111093947834982832456459186E-1),
+l10 = L(-1.000000000000532974938900317952530453248E-1),
+l11 =  L(9.090909090915566247008015301349979892689E-2),
+l12 = L(-8.333333211818065121250921925397567745734E-2),
+l13 =  L(7.692307559897661630807048686258659316091E-2),
+l14 = L(-7.144242754190814657241902218399056829264E-2),
+l15 =  L(6.668057591071739754844678883223432347481E-2);
+
+/* Lookup table of ln(t) - (t-1)
+    t = 0.5 + (k+26)/128)
+    k = 0, ..., 91   */
+static const _Float128 logtbl[92] = {
+L(-5.5345593589352099112142921677820359632418E-2),
+L(-5.2108257402767124761784665198737642086148E-2),
+L(-4.8991686870576856279407775480686721935120E-2),
+L(-4.5993270766361228596215288742353061431071E-2),
+L(-4.3110481649613269682442058976885699556950E-2),
+L(-4.0340872319076331310838085093194799765520E-2),
+L(-3.7682072451780927439219005993827431503510E-2),
+L(-3.5131785416234343803903228503274262719586E-2),
+L(-3.2687785249045246292687241862699949178831E-2),
+L(-3.0347913785027239068190798397055267411813E-2),
+L(-2.8110077931525797884641940838507561326298E-2),
+L(-2.5972247078357715036426583294246819637618E-2),
+L(-2.3932450635346084858612873953407168217307E-2),
+L(-2.1988775689981395152022535153795155900240E-2),
+L(-2.0139364778244501615441044267387667496733E-2),
+L(-1.8382413762093794819267536615342902718324E-2),
+L(-1.6716169807550022358923589720001638093023E-2),
+L(-1.5138929457710992616226033183958974965355E-2),
+L(-1.3649036795397472900424896523305726435029E-2),
+L(-1.2244881690473465543308397998034325468152E-2),
+L(-1.0924898127200937840689817557742469105693E-2),
+L(-9.6875626072830301572839422532631079809328E-3),
+L(-8.5313926245226231463436209313499745894157E-3),
+L(-7.4549452072765973384933565912143044991706E-3),
+L(-6.4568155251217050991200599386801665681310E-3),
+L(-5.5356355563671005131126851708522185605193E-3),
+L(-4.6900728132525199028885749289712348829878E-3),
+L(-3.9188291218610470766469347968659624282519E-3),
+L(-3.2206394539524058873423550293617843896540E-3),
+L(-2.5942708080877805657374888909297113032132E-3),
+L(-2.0385211375711716729239156839929281289086E-3),
+L(-1.5522183228760777967376942769773768850872E-3),
+L(-1.1342191863606077520036253234446621373191E-3),
+L(-7.8340854719967065861624024730268350459991E-4),
+L(-4.9869831458030115699628274852562992756174E-4),
+L(-2.7902661731604211834685052867305795169688E-4),
+L(-1.2335696813916860754951146082826952093496E-4),
+L(-3.0677461025892873184042490943581654591817E-5),
+#define ZERO logtbl[38]
+ L(0.0000000000000000000000000000000000000000E0),
+L(-3.0359557945051052537099938863236321874198E-5),
+L(-1.2081346403474584914595395755316412213151E-4),
+L(-2.7044071846562177120083903771008342059094E-4),
+L(-4.7834133324631162897179240322783590830326E-4),
+L(-7.4363569786340080624467487620270965403695E-4),
+L(-1.0654639687057968333207323853366578860679E-3),
+L(-1.4429854811877171341298062134712230604279E-3),
+L(-1.8753781835651574193938679595797367137975E-3),
+L(-2.3618380914922506054347222273705859653658E-3),
+L(-2.9015787624124743013946600163375853631299E-3),
+L(-3.4938307889254087318399313316921940859043E-3),
+L(-4.1378413103128673800485306215154712148146E-3),
+L(-4.8328735414488877044289435125365629849599E-3),
+L(-5.5782063183564351739381962360253116934243E-3),
+L(-6.3731336597098858051938306767880719015261E-3),
+L(-7.2169643436165454612058905294782949315193E-3),
+L(-8.1090214990427641365934846191367315083867E-3),
+L(-9.0486422112807274112838713105168375482480E-3),
+L(-1.0035177140880864314674126398350812606841E-2),
+L(-1.1067990155502102718064936259435676477423E-2),
+L(-1.2146457974158024928196575103115488672416E-2),
+L(-1.3269969823361415906628825374158424754308E-2),
+L(-1.4437927104692837124388550722759686270765E-2),
+L(-1.5649743073340777659901053944852735064621E-2),
+L(-1.6904842527181702880599758489058031645317E-2),
+L(-1.8202661505988007336096407340750378994209E-2),
+L(-1.9542647000370545390701192438691126552961E-2),
+L(-2.0924256670080119637427928803038530924742E-2),
+L(-2.2346958571309108496179613803760727786257E-2),
+L(-2.3810230892650362330447187267648486279460E-2),
+L(-2.5313561699385640380910474255652501521033E-2),
+L(-2.6856448685790244233704909690165496625399E-2),
+L(-2.8438398935154170008519274953860128449036E-2),
+L(-3.0058928687233090922411781058956589863039E-2),
+L(-3.1717563112854831855692484086486099896614E-2),
+L(-3.3413836095418743219397234253475252001090E-2),
+L(-3.5147290019036555862676702093393332533702E-2),
+L(-3.6917475563073933027920505457688955423688E-2),
+L(-3.8723951502862058660874073462456610731178E-2),
+L(-4.0566284516358241168330505467000838017425E-2),
+L(-4.2444048996543693813649967076598766917965E-2),
+L(-4.4356826869355401653098777649745233339196E-2),
+L(-4.6304207416957323121106944474331029996141E-2),
+L(-4.8285787106164123613318093945035804818364E-2),
+L(-5.0301169421838218987124461766244507342648E-2),
+L(-5.2349964705088137924875459464622098310997E-2),
+L(-5.4431789996103111613753440311680967840214E-2),
+L(-5.6546268881465384189752786409400404404794E-2),
+L(-5.8693031345788023909329239565012647817664E-2),
+L(-6.0871713627532018185577188079210189048340E-2),
+L(-6.3081958078862169742820420185833800925568E-2),
+L(-6.5323413029406789694910800219643791556918E-2),
+L(-6.7595732653791419081537811574227049288168E-2)
+};
+
+/* ln(2) = ln2a + ln2b with extended precision. */
+static const _Float128
+  ln2a = L(6.93145751953125e-1),
+  ln2b = L(1.4286068203094172321214581765680755001344E-6);
+
+_Float128
+__ieee754_logl(_Float128 x)
+{
+  _Float128 z, y, w;
+  ieee854_long_double_shape_type u, t;
+  unsigned int m;
+  int k, e;
+
+  u.value = x;
+  m = u.parts32.w0;
+
+  /* Check for IEEE special cases.  */
+  k = m & 0x7fffffff;
+  /* log(0) = -infinity. */
+  if ((k | u.parts32.w1 | u.parts32.w2 | u.parts32.w3) == 0)
+    {
+      return L(-0.5) / ZERO;
+    }
+  /* log ( x < 0 ) = NaN */
+  if (m & 0x80000000)
+    {
+      return (x - x) / ZERO;
+    }
+  /* log (infinity or NaN) */
+  if (k >= 0x7fff0000)
+    {
+      return x + x;
+    }
+
+  /* Extract exponent and reduce domain to 0.703125 <= u < 1.40625  */
+  u.value = __frexpl (x, &e);
+  m = u.parts32.w0 & 0xffff;
+  m |= 0x10000;
+  /* Find lookup table index k from high order bits of the significand. */
+  if (m < 0x16800)
+    {
+      k = (m - 0xff00) >> 9;
+      /* t is the argument 0.5 + (k+26)/128
+	 of the nearest item to u in the lookup table.  */
+      t.parts32.w0 = 0x3fff0000 + (k << 9);
+      t.parts32.w1 = 0;
+      t.parts32.w2 = 0;
+      t.parts32.w3 = 0;
+      u.parts32.w0 += 0x10000;
+      e -= 1;
+      k += 64;
+    }
+  else
+    {
+      k = (m - 0xfe00) >> 10;
+      t.parts32.w0 = 0x3ffe0000 + (k << 10);
+      t.parts32.w1 = 0;
+      t.parts32.w2 = 0;
+      t.parts32.w3 = 0;
+    }
+  /* On this interval the table is not used due to cancellation error.  */
+  if ((x <= L(1.0078125)) && (x >= L(0.9921875)))
+    {
+      if (x == 1)
+	return 0;
+      z = x - 1;
+      k = 64;
+      t.value  = 1;
+      e = 0;
+    }
+  else
+    {
+      /* log(u) = log( t u/t ) = log(t) + log(u/t)
+	 log(t) is tabulated in the lookup table.
+	 Express log(u/t) = log(1+z),  where z = u/t - 1 = (u-t)/t.
+	 cf. Cody & Waite. */
+      z = (u.value - t.value) / t.value;
+    }
+  /* Series expansion of log(1+z).  */
+  w = z * z;
+  y = ((((((((((((l15 * z
+		  + l14) * z
+		 + l13) * z
+		+ l12) * z
+	       + l11) * z
+	      + l10) * z
+	     + l9) * z
+	    + l8) * z
+	   + l7) * z
+	  + l6) * z
+	 + l5) * z
+	+ l4) * z
+       + l3) * z * w;
+  y -= 0.5 * w;
+  y += e * ln2b;  /* Base 2 exponent offset times ln(2).  */
+  y += z;
+  y += logtbl[k-26]; /* log(t) - (t-1) */
+  y += (t.value - 1);
+  y += e * ln2a;
+  return y;
+}
+strong_alias (__ieee754_logl, __logl_finite)