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, 418 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/ieee754/ldbl-96/lgamma_negl.c b/REORG.TODO/sysdeps/ieee754/ldbl-96/lgamma_negl.c
new file mode 100644
index 0000000000..36beb764be
--- /dev/null
+++ b/REORG.TODO/sysdeps/ieee754/ldbl-96/lgamma_negl.c
@@ -0,0 +1,418 @@
+/* lgammal expanding around zeros.
+   Copyright (C) 2015-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C 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.
+
+   The GNU C 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 the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <float.h>
+#include <math.h>
+#include <math_private.h>
+
+static const long double lgamma_zeros[][2] =
+  {
+    { -0x2.74ff92c01f0d82acp+0L, 0x1.360cea0e5f8ed3ccp-68L },
+    { -0x2.bf6821437b201978p+0L, -0x1.95a4b4641eaebf4cp-64L },
+    { -0x3.24c1b793cb35efb8p+0L, -0xb.e699ad3d9ba6545p-68L },
+    { -0x3.f48e2a8f85fca17p+0L, -0xd.4561291236cc321p-68L },
+    { -0x4.0a139e16656030cp+0L, -0x3.9f0b0de18112ac18p-64L },
+    { -0x4.fdd5de9bbabf351p+0L, -0xd.0aa4076988501d8p-68L },
+    { -0x5.021a95fc2db64328p+0L, -0x2.4c56e595394decc8p-64L },
+    { -0x5.ffa4bd647d0357ep+0L, 0x2.b129d342ce12071cp-64L },
+    { -0x6.005ac9625f233b6p+0L, -0x7.c2d96d16385cb868p-68L },
+    { -0x6.fff2fddae1bbff4p+0L, 0x2.9d949a3dc02de0cp-64L },
+    { -0x7.000cff7b7f87adf8p+0L, 0x3.b7d23246787d54d8p-64L },
+    { -0x7.fffe5fe05673c3c8p+0L, -0x2.9e82b522b0ca9d3p-64L },
+    { -0x8.0001a01459fc9f6p+0L, -0xc.b3cec1cec857667p-68L },
+    { -0x8.ffffd1c425e81p+0L, 0x3.79b16a8b6da6181cp-64L },
+    { -0x9.00002e3bb47d86dp+0L, -0x6.d843fedc351deb78p-64L },
+    { -0x9.fffffb606bdfdcdp+0L, -0x6.2ae77a50547c69dp-68L },
+    { -0xa.0000049f93bb992p+0L, -0x7.b45d95e15441e03p-64L },
+    { -0xa.ffffff9466e9f1bp+0L, -0x3.6dacd2adbd18d05cp-64L },
+    { -0xb.0000006b9915316p+0L, 0x2.69a590015bf1b414p-64L },
+    { -0xb.fffffff70893874p+0L, 0x7.821be533c2c36878p-64L },
+    { -0xc.00000008f76c773p+0L, -0x1.567c0f0250f38792p-64L },
+    { -0xc.ffffffff4f6dcf6p+0L, -0x1.7f97a5ffc757d548p-64L },
+    { -0xd.00000000b09230ap+0L, 0x3.f997c22e46fc1c9p-64L },
+    { -0xd.fffffffff36345bp+0L, 0x4.61e7b5c1f62ee89p-64L },
+    { -0xe.000000000c9cba5p+0L, -0x4.5e94e75ec5718f78p-64L },
+    { -0xe.ffffffffff28c06p+0L, -0xc.6604ef30371f89dp-68L },
+    { -0xf.0000000000d73fap+0L, 0xc.6642f1bdf07a161p-68L },
+    { -0xf.fffffffffff28cp+0L, -0x6.0c6621f512e72e5p-64L },
+    { -0x1.000000000000d74p+4L, 0x6.0c6625ebdb406c48p-64L },
+    { -0x1.0ffffffffffff356p+4L, -0x9.c47e7a93e1c46a1p-64L },
+    { -0x1.1000000000000caap+4L, 0x9.c47e7a97778935ap-64L },
+    { -0x1.1fffffffffffff4cp+4L, 0x1.3c31dcbecd2f74d4p-64L },
+    { -0x1.20000000000000b4p+4L, -0x1.3c31dcbeca4c3b3p-64L },
+    { -0x1.2ffffffffffffff6p+4L, -0x8.5b25cbf5f545ceep-64L },
+    { -0x1.300000000000000ap+4L, 0x8.5b25cbf5f547e48p-64L },
+    { -0x1.4p+4L, 0x7.950ae90080894298p-64L },
+    { -0x1.4p+4L, -0x7.950ae9008089414p-64L },
+    { -0x1.5p+4L, 0x5.c6e3bdb73d5c63p-68L },
+    { -0x1.5p+4L, -0x5.c6e3bdb73d5c62f8p-68L },
+    { -0x1.6p+4L, 0x4.338e5b6dfe14a518p-72L },
+    { -0x1.6p+4L, -0x4.338e5b6dfe14a51p-72L },
+    { -0x1.7p+4L, 0x2.ec368262c7033b3p-76L },
+    { -0x1.7p+4L, -0x2.ec368262c7033b3p-76L },
+    { -0x1.8p+4L, 0x1.f2cf01972f577ccap-80L },
+    { -0x1.8p+4L, -0x1.f2cf01972f577ccap-80L },
+    { -0x1.9p+4L, 0x1.3f3ccdd165fa8d4ep-84L },
+    { -0x1.9p+4L, -0x1.3f3ccdd165fa8d4ep-84L },
+    { -0x1.ap+4L, 0xc.4742fe35272cd1cp-92L },
+    { -0x1.ap+4L, -0xc.4742fe35272cd1cp-92L },
+    { -0x1.bp+4L, 0x7.46ac70b733a8c828p-96L },
+    { -0x1.bp+4L, -0x7.46ac70b733a8c828p-96L },
+    { -0x1.cp+4L, 0x4.2862898d42174ddp-100L },
+    { -0x1.cp+4L, -0x4.2862898d42174ddp-100L },
+    { -0x1.dp+4L, 0x2.4b3f31686b15af58p-104L },
+    { -0x1.dp+4L, -0x2.4b3f31686b15af58p-104L },
+    { -0x1.ep+4L, 0x1.3932c5047d60e60cp-108L },
+    { -0x1.ep+4L, -0x1.3932c5047d60e60cp-108L },
+    { -0x1.fp+4L, 0xa.1a6973c1fade217p-116L },
+    { -0x1.fp+4L, -0xa.1a6973c1fade217p-116L },
+    { -0x2p+4L, 0x5.0d34b9e0fd6f10b8p-120L },
+    { -0x2p+4L, -0x5.0d34b9e0fd6f10b8p-120L },
+    { -0x2.1p+4L, 0x2.73024a9ba1aa36a8p-124L },
+  };
+
+static const long double e_hi = 0x2.b7e151628aed2a6cp+0L;
+static const long double e_lo = -0x1.408ea77f630b0c38p-64L;
+
+/* Coefficients B_2k / 2k(2k-1) of x^-(2k-1) in Stirling's
+   approximation to lgamma function.  */
+
+static const long double lgamma_coeff[] =
+  {
+    0x1.5555555555555556p-4L,
+    -0xb.60b60b60b60b60bp-12L,
+    0x3.4034034034034034p-12L,
+    -0x2.7027027027027028p-12L,
+    0x3.72a3c5631fe46aep-12L,
+    -0x7.daac36664f1f208p-12L,
+    0x1.a41a41a41a41a41ap-8L,
+    -0x7.90a1b2c3d4e5f708p-8L,
+    0x2.dfd2c703c0cfff44p-4L,
+    -0x1.6476701181f39edcp+0L,
+    0xd.672219167002d3ap+0L,
+    -0x9.cd9292e6660d55bp+4L,
+    0x8.911a740da740da7p+8L,
+    -0x8.d0cc570e255bf5ap+12L,
+    0xa.8d1044d3708d1c2p+16L,
+    -0xe.8844d8a169abbc4p+20L,
+  };
+
+#define NCOEFF (sizeof (lgamma_coeff) / sizeof (lgamma_coeff[0]))
+
+/* Polynomial approximations to (|gamma(x)|-1)(x-n)/(x-x0), where n is
+   the integer end-point of the half-integer interval containing x and
+   x0 is the zero of lgamma in that half-integer interval.  Each
+   polynomial is expressed in terms of x-xm, where xm is the midpoint
+   of the interval for which the polynomial applies.  */
+
+static const long double poly_coeff[] =
+  {
+    /* Interval [-2.125, -2] (polynomial degree 13).  */
+    -0x1.0b71c5c54d42eb6cp+0L,
+    -0xc.73a1dc05f349517p-4L,
+    -0x1.ec841408528b6baep-4L,
+    -0xe.37c9da26fc3b492p-4L,
+    -0x1.03cd87c5178991ap-4L,
+    -0xe.ae9ada65ece2f39p-4L,
+    0x9.b1185505edac18dp-8L,
+    -0xe.f28c130b54d3cb2p-4L,
+    0x2.6ec1666cf44a63bp-4L,
+    -0xf.57cb2774193bbd5p-4L,
+    0x4.5ae64671a41b1c4p-4L,
+    -0xf.f48ea8b5bd3a7cep-4L,
+    0x6.7d73788a8d30ef58p-4L,
+    -0x1.11e0e4b506bd272ep+0L,
+    /* Interval [-2.25, -2.125] (polynomial degree 13).  */
+    -0xf.2930890d7d675a8p-4L,
+    -0xc.a5cfde054eab5cdp-4L,
+    0x3.9c9e0fdebb0676e4p-4L,
+    -0x1.02a5ad35605f0d8cp+0L,
+    0x9.6e9b1185d0b92edp-4L,
+    -0x1.4d8332f3d6a3959p+0L,
+    0x1.1c0c8cacd0ced3eap+0L,
+    -0x1.c9a6f592a67b1628p+0L,
+    0x1.d7e9476f96aa4bd6p+0L,
+    -0x2.921cedb488bb3318p+0L,
+    0x2.e8b3fd6ca193e4c8p+0L,
+    -0x3.cb69d9d6628e4a2p+0L,
+    0x4.95f12c73b558638p+0L,
+    -0x5.d392d0b97c02ab6p+0L,
+    /* Interval [-2.375, -2.25] (polynomial degree 14).  */
+    -0xd.7d28d505d618122p-4L,
+    -0xe.69649a304098532p-4L,
+    0xb.0d74a2827d055c5p-4L,
+    -0x1.924b09228531c00ep+0L,
+    0x1.d49b12bccee4f888p+0L,
+    -0x3.0898bb7dbb21e458p+0L,
+    0x4.207a6cad6fa10a2p+0L,
+    -0x6.39ee630b46093ad8p+0L,
+    0x8.e2e25211a3fb5ccp+0L,
+    -0xd.0e85ccd8e79c08p+0L,
+    0x1.2e45882bc17f9e16p+4L,
+    -0x1.b8b6e841815ff314p+4L,
+    0x2.7ff8bf7504fa04dcp+4L,
+    -0x3.c192e9c903352974p+4L,
+    0x5.8040b75f4ef07f98p+4L,
+    /* Interval [-2.5, -2.375] (polynomial degree 15).  */
+    -0xb.74ea1bcfff94b2cp-4L,
+    -0x1.2a82bd590c375384p+0L,
+    0x1.88020f828b968634p+0L,
+    -0x3.32279f040eb80fa4p+0L,
+    0x5.57ac825175943188p+0L,
+    -0x9.c2aedcfe10f129ep+0L,
+    0x1.12c132f2df02881ep+4L,
+    -0x1.ea94e26c0b6ffa6p+4L,
+    0x3.66b4a8bb0290013p+4L,
+    -0x6.0cf735e01f5990bp+4L,
+    0xa.c10a8db7ae99343p+4L,
+    -0x1.31edb212b315feeap+8L,
+    0x2.1f478592298b3ebp+8L,
+    -0x3.c546da5957ace6ccp+8L,
+    0x7.0e3d2a02579ba4bp+8L,
+    -0xc.b1ea961c39302f8p+8L,
+    /* Interval [-2.625, -2.5] (polynomial degree 16).  */
+    -0x3.d10108c27ebafad4p-4L,
+    0x1.cd557caff7d2b202p+0L,
+    0x3.819b4856d3995034p+0L,
+    0x6.8505cbad03dd3bd8p+0L,
+    0xb.c1b2e653aa0b924p+0L,
+    0x1.50a53a38f05f72d6p+4L,
+    0x2.57ae00cbd06efb34p+4L,
+    0x4.2b1563077a577e9p+4L,
+    0x7.6989ed790138a7f8p+4L,
+    0xd.2dd28417b4f8406p+4L,
+    0x1.76e1b71f0710803ap+8L,
+    0x2.9a7a096254ac032p+8L,
+    0x4.a0e6109e2a039788p+8L,
+    0x8.37ea17a93c877b2p+8L,
+    0xe.9506a641143612bp+8L,
+    0x1.b680ed4ea386d52p+12L,
+    0x3.28a2130c8de0ae84p+12L,
+    /* Interval [-2.75, -2.625] (polynomial degree 15).  */
+    -0x6.b5d252a56e8a7548p-4L,
+    0x1.28d60383da3ac72p+0L,
+    0x1.db6513ada8a6703ap+0L,
+    0x2.e217118f9d34aa7cp+0L,
+    0x4.450112c5cbd6256p+0L,
+    0x6.4af99151e972f92p+0L,
+    0x9.2db598b5b183cd6p+0L,
+    0xd.62bef9c9adcff6ap+0L,
+    0x1.379f290d743d9774p+4L,
+    0x1.c58271ff823caa26p+4L,
+    0x2.93a871b87a06e73p+4L,
+    0x3.bf9db66103d7ec98p+4L,
+    0x5.73247c111fbf197p+4L,
+    0x7.ec8b9973ba27d008p+4L,
+    0xb.eca5f9619b39c03p+4L,
+    0x1.18f2e46411c78b1cp+8L,
+    /* Interval [-2.875, -2.75] (polynomial degree 14).  */
+    -0x8.a41b1e4f36ff88ep-4L,
+    0xc.da87d3b69dc0f34p-4L,
+    0x1.1474ad5c36158ad2p+0L,
+    0x1.761ecb90c5553996p+0L,
+    0x1.d279bff9ae234f8p+0L,
+    0x2.4e5d0055a16c5414p+0L,
+    0x2.d57545a783902f8cp+0L,
+    0x3.8514eec263aa9f98p+0L,
+    0x4.5235e338245f6fe8p+0L,
+    0x5.562b1ef200b256c8p+0L,
+    0x6.8ec9782b93bd565p+0L,
+    0x8.14baf4836483508p+0L,
+    0x9.efaf35dc712ea79p+0L,
+    0xc.8431f6a226507a9p+0L,
+    0xf.80358289a768401p+0L,
+    /* Interval [-3, -2.875] (polynomial degree 13).  */
+    -0xa.046d667e468f3e4p-4L,
+    0x9.70b88dcc006c216p-4L,
+    0xa.a8a39421c86ce9p-4L,
+    0xd.2f4d1363f321e89p-4L,
+    0xd.ca9aa1a3ab2f438p-4L,
+    0xf.cf09c31f05d02cbp-4L,
+    0x1.04b133a195686a38p+0L,
+    0x1.22b54799d0072024p+0L,
+    0x1.2c5802b869a36ae8p+0L,
+    0x1.4aadf23055d7105ep+0L,
+    0x1.5794078dd45c55d6p+0L,
+    0x1.7759069da18bcf0ap+0L,
+    0x1.8e672cefa4623f34p+0L,
+    0x1.b2acfa32c17145e6p+0L,
+  };
+
+static const size_t poly_deg[] =
+  {
+    13,
+    13,
+    14,
+    15,
+    16,
+    15,
+    14,
+    13,
+  };
+
+static const size_t poly_end[] =
+  {
+    13,
+    27,
+    42,
+    58,
+    75,
+    91,
+    106,
+    120,
+  };
+
+/* Compute sin (pi * X) for -0.25 <= X <= 0.5.  */
+
+static long double
+lg_sinpi (long double x)
+{
+  if (x <= 0.25L)
+    return __sinl (M_PIl * x);
+  else
+    return __cosl (M_PIl * (0.5L - x));
+}
+
+/* Compute cos (pi * X) for -0.25 <= X <= 0.5.  */
+
+static long double
+lg_cospi (long double x)
+{
+  if (x <= 0.25L)
+    return __cosl (M_PIl * x);
+  else
+    return __sinl (M_PIl * (0.5L - x));
+}
+
+/* Compute cot (pi * X) for -0.25 <= X <= 0.5.  */
+
+static long double
+lg_cotpi (long double x)
+{
+  return lg_cospi (x) / lg_sinpi (x);
+}
+
+/* Compute lgamma of a negative argument -33 < X < -2, setting
+   *SIGNGAMP accordingly.  */
+
+long double
+__lgamma_negl (long double x, int *signgamp)
+{
+  /* Determine the half-integer region X lies in, handle exact
+     integers and determine the sign of the result.  */
+  int i = __floorl (-2 * x);
+  if ((i & 1) == 0 && i == -2 * x)
+    return 1.0L / 0.0L;
+  long double xn = ((i & 1) == 0 ? -i / 2 : (-i - 1) / 2);
+  i -= 4;
+  *signgamp = ((i & 2) == 0 ? -1 : 1);
+
+  SET_RESTORE_ROUNDL (FE_TONEAREST);
+
+  /* Expand around the zero X0 = X0_HI + X0_LO.  */
+  long double x0_hi = lgamma_zeros[i][0], x0_lo = lgamma_zeros[i][1];
+  long double xdiff = x - x0_hi - x0_lo;
+
+  /* For arguments in the range -3 to -2, use polynomial
+     approximations to an adjusted version of the gamma function.  */
+  if (i < 2)
+    {
+      int j = __floorl (-8 * x) - 16;
+      long double xm = (-33 - 2 * j) * 0.0625L;
+      long double x_adj = x - xm;
+      size_t deg = poly_deg[j];
+      size_t end = poly_end[j];
+      long double g = poly_coeff[end];
+      for (size_t j = 1; j <= deg; j++)
+	g = g * x_adj + poly_coeff[end - j];
+      return __log1pl (g * xdiff / (x - xn));
+    }
+
+  /* The result we want is log (sinpi (X0) / sinpi (X))
+     + log (gamma (1 - X0) / gamma (1 - X)).  */
+  long double x_idiff = fabsl (xn - x), x0_idiff = fabsl (xn - x0_hi - x0_lo);
+  long double log_sinpi_ratio;
+  if (x0_idiff < x_idiff * 0.5L)
+    /* Use log not log1p to avoid inaccuracy from log1p of arguments
+       close to -1.  */
+    log_sinpi_ratio = __ieee754_logl (lg_sinpi (x0_idiff)
+				      / lg_sinpi (x_idiff));
+  else
+    {
+      /* Use log1p not log to avoid inaccuracy from log of arguments
+	 close to 1.  X0DIFF2 has positive sign if X0 is further from
+	 XN than X is from XN, negative sign otherwise.  */
+      long double x0diff2 = ((i & 1) == 0 ? xdiff : -xdiff) * 0.5L;
+      long double sx0d2 = lg_sinpi (x0diff2);
+      long double cx0d2 = lg_cospi (x0diff2);
+      log_sinpi_ratio = __log1pl (2 * sx0d2
+				  * (-sx0d2 + cx0d2 * lg_cotpi (x_idiff)));
+    }
+
+  long double log_gamma_ratio;
+  long double y0 = 1 - x0_hi;
+  long double y0_eps = -x0_hi + (1 - y0) - x0_lo;
+  long double y = 1 - x;
+  long double y_eps = -x + (1 - y);
+  /* We now wish to compute LOG_GAMMA_RATIO
+     = log (gamma (Y0 + Y0_EPS) / gamma (Y + Y_EPS)).  XDIFF
+     accurately approximates the difference Y0 + Y0_EPS - Y -
+     Y_EPS.  Use Stirling's approximation.  First, we may need to
+     adjust into the range where Stirling's approximation is
+     sufficiently accurate.  */
+  long double log_gamma_adj = 0;
+  if (i < 8)
+    {
+      int n_up = (9 - i) / 2;
+      long double ny0, ny0_eps, ny, ny_eps;
+      ny0 = y0 + n_up;
+      ny0_eps = y0 - (ny0 - n_up) + y0_eps;
+      y0 = ny0;
+      y0_eps = ny0_eps;
+      ny = y + n_up;
+      ny_eps = y - (ny - n_up) + y_eps;
+      y = ny;
+      y_eps = ny_eps;
+      long double prodm1 = __lgamma_productl (xdiff, y - n_up, y_eps, n_up);
+      log_gamma_adj = -__log1pl (prodm1);
+    }
+  long double log_gamma_high
+    = (xdiff * __log1pl ((y0 - e_hi - e_lo + y0_eps) / e_hi)
+       + (y - 0.5L + y_eps) * __log1pl (xdiff / y) + log_gamma_adj);
+  /* Compute the sum of (B_2k / 2k(2k-1))(Y0^-(2k-1) - Y^-(2k-1)).  */
+  long double y0r = 1 / y0, yr = 1 / y;
+  long double y0r2 = y0r * y0r, yr2 = yr * yr;
+  long double rdiff = -xdiff / (y * y0);
+  long double bterm[NCOEFF];
+  long double dlast = rdiff, elast = rdiff * yr * (yr + y0r);
+  bterm[0] = dlast * lgamma_coeff[0];
+  for (size_t j = 1; j < NCOEFF; j++)
+    {
+      long double dnext = dlast * y0r2 + elast;
+      long double enext = elast * yr2;
+      bterm[j] = dnext * lgamma_coeff[j];
+      dlast = dnext;
+      elast = enext;
+    }
+  long double log_gamma_low = 0;
+  for (size_t j = 0; j < NCOEFF; j++)
+    log_gamma_low += bterm[NCOEFF - 1 - j];
+  log_gamma_ratio = log_gamma_high + log_gamma_low;
+
+  return log_sinpi_ratio + log_gamma_ratio;
+}