glibc/sysdeps/ieee754/ldbl-128/lgamma_negl.c
Paul Eggert 5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00

553 lines
24 KiB
C

/* lgammal expanding around zeros.
Copyright (C) 2015-2019 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
<https://www.gnu.org/licenses/>. */
#include <float.h>
#include <math.h>
#include <math_private.h>
#include <fenv_private.h>
static const _Float128 lgamma_zeros[][2] =
{
{ L(-0x2.74ff92c01f0d82abec9f315f1a08p+0), L(0xe.d3ccb7fb2658634a2b9f6b2ba81p-116) },
{ L(-0x2.bf6821437b20197995a4b4641eaep+0), L(-0xb.f4b00b4829f961e428533e6ad048p-116) },
{ L(-0x3.24c1b793cb35efb8be699ad3d9bap+0), L(-0x6.5454cb7fac60e3f16d9d7840c2ep-116) },
{ L(-0x3.f48e2a8f85fca170d4561291236cp+0), L(-0xc.320a4887d1cb4c711828a75d5758p-116) },
{ L(-0x4.0a139e16656030c39f0b0de18114p+0), L(0x1.53e84029416e1242006b2b3d1cfp-112) },
{ L(-0x4.fdd5de9bbabf3510d0aa40769884p+0), L(-0x1.01d7d78125286f78d1e501f14966p-112) },
{ L(-0x5.021a95fc2db6432a4c56e595394cp+0), L(-0x1.ecc6af0430d4fe5746fa7233356fp-112) },
{ L(-0x5.ffa4bd647d0357dd4ed62cbd31ecp+0), L(-0x1.f8e3f8e5deba2d67dbd70dd96ce1p-112) },
{ L(-0x6.005ac9625f233b607c2d96d16384p+0), L(-0x1.cb86ac569340cf1e5f24df7aab7bp-112) },
{ L(-0x6.fff2fddae1bbff3d626b65c23fd4p+0), L(0x1.e0bfcff5c457ebcf4d3ad9674167p-112) },
{ L(-0x7.000cff7b7f87adf4482dcdb98784p+0), L(0x1.54d99e35a74d6407b80292df199fp-112) },
{ L(-0x7.fffe5fe05673c3ca9e82b522b0ccp+0), L(0x1.62d177c832e0eb42c2faffd1b145p-112) },
{ L(-0x8.0001a01459fc9f60cb3cec1cec88p+0), L(0x2.8998835ac7277f7bcef67c47f188p-112) },
{ L(-0x8.ffffd1c425e80ffc864e95749258p+0), L(-0x1.e7e20210e7f81cf781b44e9d2b02p-112) },
{ L(-0x9.00002e3bb47d86d6d843fedc352p+0), L(0x2.14852f613a16291751d2ab751f7ep-112) },
{ L(-0x9.fffffb606bdfdcd062ae77a50548p+0), L(0x3.962d1490cc2e8f031c7007eaa1ap-116) },
{ L(-0xa.0000049f93bb9927b45d95e1544p+0), L(-0x1.e03086db9146a9287bd4f2172d5ap-112) },
{ L(-0xa.ffffff9466e9f1b36dacd2adbd18p+0), L(-0xd.05a4e458062f3f95345a4d9c9b6p-116) },
{ L(-0xb.0000006b9915315d965a6ffea41p+0), L(0x1.b415c6fff233e7b7fdc3a094246fp-112) },
{ L(-0xb.fffffff7089387387de41acc3d4p+0), L(0x3.687427c6373bd74a10306e10a28ep-112) },
{ L(-0xc.00000008f76c7731567c0f0250fp+0), L(-0x3.87920df5675833859190eb128ef6p-112) },
{ L(-0xc.ffffffff4f6dcf617f97a5ffc758p+0), L(0x2.ab72d76f32eaee2d1a42ed515d3ap-116) },
{ L(-0xd.00000000b092309c06683dd1b9p+0), L(-0x3.e3700857a15c19ac5a611de9688ap-112) },
{ L(-0xd.fffffffff36345ab9e184a3e09dp+0), L(-0x1.176dc48e47f62d917973dd44e553p-112) },
{ L(-0xe.000000000c9cba545e94e75ec57p+0), L(-0x1.8f753e2501e757a17cf2ecbeeb89p-112) },
{ L(-0xe.ffffffffff28c060c6604ef3037p+0), L(-0x1.f89d37357c9e3dc17c6c6e63becap-112) },
{ L(-0xf.0000000000d73f9f399bd0e420f8p+0), L(-0x5.e9ee31b0b890744fc0e3fbc01048p-116) },
{ L(-0xf.fffffffffff28c060c6621f512e8p+0), L(0xd.1b2eec9d960bd9adc5be5f5fa5p-116) },
{ L(-0x1.000000000000d73f9f399da1424cp+4), L(0x6.c46e0e88305d2800f0e414c506a8p-116) },
{ L(-0x1.0ffffffffffff3569c47e7a93e1cp+4), L(-0x4.6a08a2e008a998ebabb8087efa2cp-112) },
{ L(-0x1.1000000000000ca963b818568887p+4), L(-0x6.ca5a3a64ec15db0a95caf2c9ffb4p-112) },
{ L(-0x1.1fffffffffffff4bec3ce234132dp+4), L(-0x8.b2b726187c841cb92cd5221e444p-116) },
{ L(-0x1.20000000000000b413c31dcbeca5p+4), L(0x3.c4d005344b6cd0e7231120294abcp-112) },
{ L(-0x1.2ffffffffffffff685b25cbf5f54p+4), L(-0x5.ced932e38485f7dd296b8fa41448p-112) },
{ L(-0x1.30000000000000097a4da340a0acp+4), L(0x7.e484e0e0ffe38d406ebebe112f88p-112) },
{ L(-0x1.3fffffffffffffff86af516ff7f7p+4), L(-0x6.bd67e720d57854502b7db75e1718p-112) },
{ L(-0x1.40000000000000007950ae900809p+4), L(0x6.bec33375cac025d9c073168c5d9p-112) },
{ L(-0x1.4ffffffffffffffffa391c4248c3p+4), L(0x5.c63022b62b5484ba346524db607p-112) },
{ L(-0x1.500000000000000005c6e3bdb73dp+4), L(-0x5.c62f55ed5322b2685c5e9a51e6a8p-112) },
{ L(-0x1.5fffffffffffffffffbcc71a492p+4), L(-0x1.eb5aeb96c74d7ad25e060528fb5p-112) },
{ L(-0x1.6000000000000000004338e5b6ep+4), L(0x1.eb5aec04b2f2eb663e4e3d8a018cp-112) },
{ L(-0x1.6ffffffffffffffffffd13c97d9dp+4), L(-0x3.8fcc4d08d6fe5aa56ab04307ce7ep-112) },
{ L(-0x1.70000000000000000002ec368263p+4), L(0x3.8fcc4d090cee2f5d0b69a99c353cp-112) },
{ L(-0x1.7fffffffffffffffffffe0d30fe7p+4), L(0x7.2f577cca4b4c8cb1dc14001ac5ecp-112) },
{ L(-0x1.800000000000000000001f2cf019p+4), L(-0x7.2f577cca4b3442e35f0040b3b9e8p-112) },
{ L(-0x1.8ffffffffffffffffffffec0c332p+4), L(-0x2.e9a0572b1bb5b95f346a92d67a6p-112) },
{ L(-0x1.90000000000000000000013f3ccep+4), L(0x2.e9a0572b1bb5c371ddb3561705ap-112) },
{ L(-0x1.9ffffffffffffffffffffff3b8bdp+4), L(-0x1.cad8d32e386fd783e97296d63dcbp-116) },
{ L(-0x1.a0000000000000000000000c4743p+4), L(0x1.cad8d32e386fd7c1ab8c1fe34c0ep-116) },
{ L(-0x1.afffffffffffffffffffffff8b95p+4), L(-0x3.8f48cc5737d5979c39db806c5406p-112) },
{ L(-0x1.b00000000000000000000000746bp+4), L(0x3.8f48cc5737d5979c3b3a6bda06f6p-112) },
{ L(-0x1.bffffffffffffffffffffffffbd8p+4), L(0x6.2898d42174dcf171470d8c8c6028p-112) },
{ L(-0x1.c000000000000000000000000428p+4), L(-0x6.2898d42174dcf171470d18ba412cp-112) },
{ L(-0x1.cfffffffffffffffffffffffffdbp+4), L(-0x4.c0ce9794ea50a839e311320bde94p-112) },
{ L(-0x1.d000000000000000000000000025p+4), L(0x4.c0ce9794ea50a839e311322f7cf8p-112) },
{ L(-0x1.dfffffffffffffffffffffffffffp+4), L(0x3.932c5047d60e60caded4c298a174p-112) },
{ L(-0x1.e000000000000000000000000001p+4), L(-0x3.932c5047d60e60caded4c298973ap-112) },
{ L(-0x1.fp+4), L(0xa.1a6973c1fade2170f7237d35fe3p-116) },
{ L(-0x1.fp+4), L(-0xa.1a6973c1fade2170f7237d35fe08p-116) },
{ L(-0x2p+4), L(0x5.0d34b9e0fd6f10b87b91be9aff1p-120) },
{ L(-0x2p+4), L(-0x5.0d34b9e0fd6f10b87b91be9aff0cp-120) },
{ L(-0x2.1p+4), L(0x2.73024a9ba1aa36a7059bff52e844p-124) },
{ L(-0x2.1p+4), L(-0x2.73024a9ba1aa36a7059bff52e844p-124) },
{ L(-0x2.2p+4), L(0x1.2710231c0fd7a13f8a2b4af9d6b7p-128) },
{ L(-0x2.2p+4), L(-0x1.2710231c0fd7a13f8a2b4af9d6b7p-128) },
{ L(-0x2.3p+4), L(0x8.6e2ce38b6c8f9419e3fad3f0312p-136) },
{ L(-0x2.3p+4), L(-0x8.6e2ce38b6c8f9419e3fad3f0312p-136) },
{ L(-0x2.4p+4), L(0x3.bf30652185952560d71a254e4eb8p-140) },
{ L(-0x2.4p+4), L(-0x3.bf30652185952560d71a254e4eb8p-140) },
{ L(-0x2.5p+4), L(0x1.9ec8d1c94e85af4c78b15c3d89d3p-144) },
{ L(-0x2.5p+4), L(-0x1.9ec8d1c94e85af4c78b15c3d89d3p-144) },
{ L(-0x2.6p+4), L(0xa.ea565ce061d57489e9b85276274p-152) },
{ L(-0x2.6p+4), L(-0xa.ea565ce061d57489e9b85276274p-152) },
{ L(-0x2.7p+4), L(0x4.7a6512692eb37804111dabad30ecp-156) },
{ L(-0x2.7p+4), L(-0x4.7a6512692eb37804111dabad30ecp-156) },
{ L(-0x2.8p+4), L(0x1.ca8ed42a12ae3001a07244abad2bp-160) },
{ L(-0x2.8p+4), L(-0x1.ca8ed42a12ae3001a07244abad2bp-160) },
{ L(-0x2.9p+4), L(0xb.2f30e1ce812063f12e7e8d8d96e8p-168) },
{ L(-0x2.9p+4), L(-0xb.2f30e1ce812063f12e7e8d8d96e8p-168) },
{ L(-0x2.ap+4), L(0x4.42bd49d4c37a0db136489772e428p-172) },
{ L(-0x2.ap+4), L(-0x4.42bd49d4c37a0db136489772e428p-172) },
{ L(-0x2.bp+4), L(0x1.95db45257e5122dcbae56def372p-176) },
{ L(-0x2.bp+4), L(-0x1.95db45257e5122dcbae56def372p-176) },
{ L(-0x2.cp+4), L(0x9.3958d81ff63527ecf993f3fb6f48p-184) },
{ L(-0x2.cp+4), L(-0x9.3958d81ff63527ecf993f3fb6f48p-184) },
{ L(-0x2.dp+4), L(0x3.47970e4440c8f1c058bd238c9958p-188) },
{ L(-0x2.dp+4), L(-0x3.47970e4440c8f1c058bd238c9958p-188) },
{ L(-0x2.ep+4), L(0x1.240804f65951062ca46e4f25c608p-192) },
{ L(-0x2.ep+4), L(-0x1.240804f65951062ca46e4f25c608p-192) },
{ L(-0x2.fp+4), L(0x6.36a382849fae6de2d15362d8a394p-200) },
{ L(-0x2.fp+4), L(-0x6.36a382849fae6de2d15362d8a394p-200) },
{ L(-0x3p+4), L(0x2.123680d6dfe4cf4b9b1bcb9d8bdcp-204) },
{ L(-0x3p+4), L(-0x2.123680d6dfe4cf4b9b1bcb9d8bdcp-204) },
{ L(-0x3.1p+4), L(0xa.d21786ff5842eca51fea0870919p-212) },
{ L(-0x3.1p+4), L(-0xa.d21786ff5842eca51fea0870919p-212) },
{ L(-0x3.2p+4), L(0x3.766dedc259af040be140a68a6c04p-216) },
};
static const _Float128 e_hi = L(0x2.b7e151628aed2a6abf7158809cf4p+0);
static const _Float128 e_lo = L(0xf.3c762e7160f38b4da56a784d9048p-116);
/* Coefficients B_2k / 2k(2k-1) of x^-(2k-1) in Stirling's
approximation to lgamma function. */
static const _Float128 lgamma_coeff[] =
{
L(0x1.5555555555555555555555555555p-4),
L(-0xb.60b60b60b60b60b60b60b60b60b8p-12),
L(0x3.4034034034034034034034034034p-12),
L(-0x2.7027027027027027027027027028p-12),
L(0x3.72a3c5631fe46ae1d4e700dca8f2p-12),
L(-0x7.daac36664f1f207daac36664f1f4p-12),
L(0x1.a41a41a41a41a41a41a41a41a41ap-8),
L(-0x7.90a1b2c3d4e5f708192a3b4c5d7p-8),
L(0x2.dfd2c703c0cfff430edfd2c703cp-4),
L(-0x1.6476701181f39edbdb9ce625987dp+0),
L(0xd.672219167002d3a7a9c886459cp+0),
L(-0x9.cd9292e6660d55b3f712eb9e07c8p+4),
L(0x8.911a740da740da740da740da741p+8),
L(-0x8.d0cc570e255bf59ff6eec24b49p+12),
L(0xa.8d1044d3708d1c219ee4fdc446ap+16),
L(-0xe.8844d8a169abbc406169abbc406p+20),
L(0x1.6d29a0f6433b79890cede62433b8p+28),
L(-0x2.88a233b3c8cddaba9809357125d8p+32),
L(0x5.0dde6f27500939a85c40939a85c4p+36),
L(-0xb.4005bde03d4642a243581714af68p+40),
L(0x1.bc8cd6f8f1f755c78753cdb5d5c9p+48),
L(-0x4.bbebb143bb94de5a0284fa7ec424p+52),
L(0xe.2e1337f5af0bed90b6b0a352d4fp+56),
L(-0x2.e78250162b62405ad3e4bfe61b38p+64),
L(0xa.5f7eef9e71ac7c80326ab4cc8bfp+68),
L(-0x2.83be0395e550213369924971b21ap+76),
L(0xa.8ebfe48da17dd999790760b0cep+80),
};
#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 _Float128 poly_coeff[] =
{
/* Interval [-2.125, -2] (polynomial degree 23). */
L(-0x1.0b71c5c54d42eb6c17f30b7aa8f5p+0),
L(-0xc.73a1dc05f34951602554c6d7506p-4),
L(-0x1.ec841408528b51473e6c425ee5ffp-4),
L(-0xe.37c9da26fc3c9a3c1844c8c7f1cp-4),
L(-0x1.03cd87c519305703b021fa33f827p-4),
L(-0xe.ae9ada65e09aa7f1c75216128f58p-4),
L(0x9.b11855a4864b5731cf85736015a8p-8),
L(-0xe.f28c133e697a95c28607c9701dep-4),
L(0x2.6ec14a1c586a72a7cc33ee569d6ap-4),
L(-0xf.57cab973e14464a262fc24723c38p-4),
L(0x4.5b0fc25f16e52997b2886bbae808p-4),
L(-0xf.f50e59f1a9b56e76e988dac9ccf8p-4),
L(0x6.5f5eae15e9a93369e1d85146c6fcp-4),
L(-0x1.0d2422daac459e33e0994325ed23p+0),
L(0x8.82000a0e7401fb1117a0e6606928p-4),
L(-0x1.1f492f178a3f1b19f58a2ca68e55p+0),
L(0xa.cb545f949899a04c160b19389abp-4),
L(-0x1.36165a1b155ba3db3d1b77caf498p+0),
L(0xd.44c5d5576f74302e5cf79e183eep-4),
L(-0x1.51f22e0cdd33d3d481e326c02f3ep+0),
L(0xf.f73a349c08244ac389c007779bfp-4),
L(-0x1.73317bf626156ba716747c4ca866p+0),
L(0x1.379c3c97b9bc71e1c1c4802dd657p+0),
L(-0x1.a72a351c54f902d483052000f5dfp+0),
/* Interval [-2.25, -2.125] (polynomial degree 24). */
L(-0xf.2930890d7d675a80c36afb0fd5e8p-4),
L(-0xc.a5cfde054eab5c6770daeca577f8p-4),
L(0x3.9c9e0fdebb07cdf89c61d41c9238p-4),
L(-0x1.02a5ad35605fcf4af65a6dbacb84p+0),
L(0x9.6e9b1185bb48be9de1918e00a2e8p-4),
L(-0x1.4d8332f3cfbfa116fd611e9ce90dp+0),
L(0x1.1c0c8cb4d9f4b1d490e1a41fae4dp+0),
L(-0x1.c9a6f5ae9130cd0299e293a42714p+0),
L(0x1.d7e9307fd58a2ea997f29573a112p+0),
L(-0x2.921cb3473d96178ca2a11d2a8d46p+0),
L(0x2.e8d59113b6f3409ff8db226e9988p+0),
L(-0x3.cbab931625a1ae2b26756817f264p+0),
L(0x4.7d9f0f05d5296d18663ca003912p+0),
L(-0x5.ade9cba12a14ea485667b7135bbp+0),
L(0x6.dc983a5da74fb48e767b7fec0a3p+0),
L(-0x8.8d9ed454ae31d9e138dd8ee0d1a8p+0),
L(0xa.6fa099d4e7c202e0c0fd6ed8492p+0),
L(-0xc.ebc552a8090a0f0115e92d4ebbc8p+0),
L(0xf.d695e4772c0d829b53fba9ca5568p+0),
L(-0x1.38c32ae38e5e9eb79b2a4c5570a9p+4),
L(0x1.8035145646cfab49306d0999a51bp+4),
L(-0x1.d930adbb03dd342a4c2a8c4e1af6p+4),
L(0x2.45c2edb1b4943ddb3686cd9c6524p+4),
L(-0x2.e818ebbfafe2f916fa21abf7756p+4),
L(0x3.9804ce51d0fb9a430a711fd7307p+4),
/* Interval [-2.375, -2.25] (polynomial degree 25). */
L(-0xd.7d28d505d6181218a25f31d5e45p-4),
L(-0xe.69649a3040985140cdf946829fap-4),
L(0xb.0d74a2827d053a8d44595012484p-4),
L(-0x1.924b0922853617cac181afbc08ddp+0),
L(0x1.d49b12bccf0a568582e2d3c410f3p+0),
L(-0x3.0898bb7d8c4093e636279c791244p+0),
L(0x4.207a6cac711cb53868e8a5057eep+0),
L(-0x6.39ee63ea4fb1dcab0c9144bf3ddcp+0),
L(0x8.e2e2556a797b649bf3f53bd26718p+0),
L(-0xd.0e83ac82552ef12af508589e7a8p+0),
L(0x1.2e4525e0ce6670563c6484a82b05p+4),
L(-0x1.b8e350d6a8f2b222fa390a57c23dp+4),
L(0x2.805cd69b919087d8a80295892c2cp+4),
L(-0x3.a42585424a1b7e64c71743ab014p+4),
L(0x5.4b4f409f98de49f7bfb03c05f984p+4),
L(-0x7.b3c5827fbe934bc820d6832fb9fcp+4),
L(0xb.33b7b90cc96c425526e0d0866e7p+4),
L(-0x1.04b77047ac4f59ee3775ca10df0dp+8),
L(0x1.7b366f5e94a34f41386eac086313p+8),
L(-0x2.2797338429385c9849ca6355bfc2p+8),
L(0x3.225273cf92a27c9aac1b35511256p+8),
L(-0x4.8f078aa48afe6cb3a4e89690f898p+8),
L(0x6.9f311d7b6654fc1d0b5195141d04p+8),
L(-0x9.a0c297b6b4621619ca9bacc48ed8p+8),
L(0xe.ce1f06b6f90d92138232a76e4cap+8),
L(-0x1.5b0e6806fa064daf011613e43b17p+12),
/* Interval [-2.5, -2.375] (polynomial degree 27). */
L(-0xb.74ea1bcfff94b2c01afba9daa7d8p-4),
L(-0x1.2a82bd590c37538cab143308de4dp+0),
L(0x1.88020f828b966fec66b8649fd6fcp+0),
L(-0x3.32279f040eb694970e9db24863dcp+0),
L(0x5.57ac82517767e68a721005853864p+0),
L(-0x9.c2aedcfe22833de43834a0a6cc4p+0),
L(0x1.12c132f1f5577f99e1a0ed3538e1p+4),
L(-0x1.ea94e26628a3de3597f7bb55a948p+4),
L(0x3.66b4ac4fa582f58b59f96b2f7c7p+4),
L(-0x6.0cf746a9cf4cba8c39afcc73fc84p+4),
L(0xa.c102ef2c20d75a342197df7fedf8p+4),
L(-0x1.31ebff06e8f14626782df58db3b6p+8),
L(0x2.1fd6f0c0e710994e059b9dbdb1fep+8),
L(-0x3.c6d76040407f447f8b5074f07706p+8),
L(0x6.b6d18e0d8feb4c2ef5af6a40ed18p+8),
L(-0xb.efaf542c529f91e34217f24ae6a8p+8),
L(0x1.53852d873210e7070f5d9eb2296p+12),
L(-0x2.5b977c0ddc6d540717173ac29fc8p+12),
L(0x4.310d452ae05100eff1e02343a724p+12),
L(-0x7.73a5d8f20c4f986a7dd1912b2968p+12),
L(0xd.3f5ea2484f3fca15eab1f4d1a218p+12),
L(-0x1.78d18aac156d1d93a2ffe7e08d3fp+16),
L(0x2.9df49ca75e5b567f5ea3e47106cp+16),
L(-0x4.a7149af8961a08aa7c3233b5bb94p+16),
L(0x8.3db10ffa742c707c25197d989798p+16),
L(-0xe.a26d6dd023cadd02041a049ec368p+16),
L(0x1.c825d90514e7c57c7fa5316f947cp+20),
L(-0x3.34bb81e5a0952df8ca1abdc6684cp+20),
/* Interval [-2.625, -2.5] (polynomial degree 28). */
L(-0x3.d10108c27ebafad533c20eac32bp-4),
L(0x1.cd557caff7d2b2085f41dbec5106p+0),
L(0x3.819b4856d399520dad9776ea2cacp+0),
L(0x6.8505cbad03dc34c5e42e8b12eb78p+0),
L(0xb.c1b2e653a9e38f82b399c94e7f08p+0),
L(0x1.50a53a38f148138105124df65419p+4),
L(0x2.57ae00cbe5232cbeeed34d89727ap+4),
L(0x4.2b156301b8604db85a601544bfp+4),
L(0x7.6989ed23ca3ca7579b3462592b5cp+4),
L(0xd.2dd2976557939517f831f5552cc8p+4),
L(0x1.76e1c3430eb860969bce40cd494p+8),
L(0x2.9a77bf5488742466db3a2c7c1ec6p+8),
L(0x4.a0d62ed7266e8eb36f725a8ebcep+8),
L(0x8.3a6184dd3021067df2f8b91e99c8p+8),
L(0xe.a0ade1538245bf55d39d7e436b1p+8),
L(0x1.a01359fae8617b5826dd74428e9p+12),
L(0x2.e3b0a32caae77251169acaca1ad4p+12),
L(0x5.2301257c81589f62b38fb5993ee8p+12),
L(0x9.21c9275db253d4e719b73b18cb9p+12),
L(0x1.03c104bc96141cda3f3fa4b112bcp+16),
L(0x1.cdc8ed65119196a08b0c78f1445p+16),
L(0x3.34f31d2eaacf34382cdb0073572ap+16),
L(0x5.b37628cadf12bf0000907d0ef294p+16),
L(0xa.22d8b332c0b1e6a616f425dfe5ap+16),
L(0x1.205b01444804c3ff922cd78b4c42p+20),
L(0x1.fe8f0cea9d1e0ff25be2470b4318p+20),
L(0x3.8872aebeb368399aee02b39340aep+20),
L(0x6.ebd560d351e84e26a4381f5b293cp+20),
L(0xc.c3644d094b0dae2fbcbf682cd428p+20),
/* Interval [-2.75, -2.625] (polynomial degree 26). */
L(-0x6.b5d252a56e8a75458a27ed1c2dd4p-4),
L(0x1.28d60383da3ac721aed3c5794da9p+0),
L(0x1.db6513ada8a66ea77d87d9a8827bp+0),
L(0x2.e217118f9d348a27f7506a707e6ep+0),
L(0x4.450112c5cbf725a0fb9802396c9p+0),
L(0x6.4af99151eae7810a75df2a0303c4p+0),
L(0x9.2db598b4a97a7f69aeef32aec758p+0),
L(0xd.62bef9c22471f5ee47ea1b9c0b5p+0),
L(0x1.379f294e412bd62328326d4222f9p+4),
L(0x1.c5827349d8865f1e8825c37c31c6p+4),
L(0x2.93a7e7a75b7568cc8cbe8c016c12p+4),
L(0x3.bf9bb882afe57edb383d41879d3ap+4),
L(0x5.73c737828cee095c43a5566731c8p+4),
L(0x7.ee4653493a7f81e0442062b3823cp+4),
L(0xb.891c6b83fc8b55bd973b5d962d6p+4),
L(0x1.0c775d7de3bf9b246c0208e0207ep+8),
L(0x1.867ee43ec4bd4f4fd56abc05110ap+8),
L(0x2.37fe9ba6695821e9822d8c8af0a6p+8),
L(0x3.3a2c667e37c942f182cd3223a936p+8),
L(0x4.b1b500eb59f3f782c7ccec88754p+8),
L(0x6.d3efd3b65b3d0d8488d30b79fa4cp+8),
L(0x9.ee8224e65bed5ced8b75eaec609p+8),
L(0xe.72416e510cca77d53fc615c1f3dp+8),
L(0x1.4fb538b0a2dfe567a8904b7e0445p+12),
L(0x1.e7f56a9266cf525a5b8cf4cb76cep+12),
L(0x2.f0365c983f68c597ee49d099cce8p+12),
L(0x4.53aa229e1b9f5b5e59625265951p+12),
/* Interval [-2.875, -2.75] (polynomial degree 24). */
L(-0x8.a41b1e4f36ff88dc820815607d68p-4),
L(0xc.da87d3b69dc0f2f9c6f368b8ca1p-4),
L(0x1.1474ad5c36158a7bea04fd2f98c6p+0),
L(0x1.761ecb90c555df6555b7dba955b6p+0),
L(0x1.d279bff9ae291caf6c4b4bcb3202p+0),
L(0x2.4e5d00559a6e2b9b5d7fe1f6689cp+0),
L(0x2.d57545a75cee8743ae2b17bc8d24p+0),
L(0x3.8514eee3aac88b89bec2307021bap+0),
L(0x4.5235e3b6e1891ffeb87fed9f8a24p+0),
L(0x5.562acdb10eef3c9a773b3e27a864p+0),
L(0x6.8ec8965c76efe03c26bff60b1194p+0),
L(0x8.15251aca144877af32658399f9b8p+0),
L(0x9.f08d56aba174d844138af782c0f8p+0),
L(0xc.3dbbeda2679e8a1346ccc3f6da88p+0),
L(0xf.0f5bfd5eacc26db308ffa0556fa8p+0),
L(0x1.28a6ccd84476fbc713d6bab49ac9p+4),
L(0x1.6d0a3ae2a3b1c8ff400641a3a21fp+4),
L(0x1.c15701b28637f87acfb6a91d33b5p+4),
L(0x2.28fbe0eccf472089b017651ca55ep+4),
L(0x2.a8a453004f6e8ffaacd1603bc3dp+4),
L(0x3.45ae4d9e1e7cd1a5dba0e4ec7f6cp+4),
L(0x4.065fbfacb7fad3e473cb577a61e8p+4),
L(0x4.f3d1473020927acac1944734a39p+4),
L(0x6.54bb091245815a36fb74e314dd18p+4),
L(0x7.d7f445129f7fb6c055e582d3f6ep+4),
/* Interval [-3, -2.875] (polynomial degree 23). */
L(-0xa.046d667e468f3e44dcae1afcc648p-4),
L(0x9.70b88dcc006c214d8d996fdf5ccp-4),
L(0xa.a8a39421c86d3ff24931a0929fp-4),
L(0xd.2f4d1363f324da2b357c8b6ec94p-4),
L(0xd.ca9aa1a3a5c00de11bf60499a97p-4),
L(0xf.cf09c31eeb52a45dfa7ebe3778dp-4),
L(0x1.04b133a39ed8a09691205660468bp+0),
L(0x1.22b547a06edda944fcb12fd9b5ecp+0),
L(0x1.2c57fce7db86a91df09602d344b3p+0),
L(0x1.4aade4894708f84795212fe257eep+0),
L(0x1.579c8b7b67ec4afed5b28c8bf787p+0),
L(0x1.776820e7fc80ae5284239733078ap+0),
L(0x1.883ab28c7301fde4ca6b8ec26ec8p+0),
L(0x1.aa2ef6e1ae52eb42c9ee83b206e3p+0),
L(0x1.bf4ad50f0a9a9311300cf0c51ee7p+0),
L(0x1.e40206e0e96b1da463814dde0d09p+0),
L(0x1.fdcbcffef3a21b29719c2bd9feb1p+0),
L(0x2.25e2e8948939c4d42cf108fae4bep+0),
L(0x2.44ce14d2b59c1c0e6bf2cfa81018p+0),
L(0x2.70ee80bbd0387162be4861c43622p+0),
L(0x2.954b64d2c2ebf3489b949c74476p+0),
L(0x2.c616e133a811c1c9446105208656p+0),
L(0x3.05a69dfe1a9ba1079f90fcf26bd4p+0),
L(0x3.410d2ad16a0506de29736e6aafdap+0),
};
static const size_t poly_deg[] =
{
23,
24,
25,
27,
28,
26,
24,
23,
};
static const size_t poly_end[] =
{
23,
48,
74,
102,
131,
158,
183,
207,
};
/* Compute sin (pi * X) for -0.25 <= X <= 0.5. */
static _Float128
lg_sinpi (_Float128 x)
{
if (x <= L(0.25))
return __sinl (M_PIl * x);
else
return __cosl (M_PIl * (L(0.5) - x));
}
/* Compute cos (pi * X) for -0.25 <= X <= 0.5. */
static _Float128
lg_cospi (_Float128 x)
{
if (x <= L(0.25))
return __cosl (M_PIl * x);
else
return __sinl (M_PIl * (L(0.5) - x));
}
/* Compute cot (pi * X) for -0.25 <= X <= 0.5. */
static _Float128
lg_cotpi (_Float128 x)
{
return lg_cospi (x) / lg_sinpi (x);
}
/* Compute lgamma of a negative argument -50 < X < -2, setting
*SIGNGAMP accordingly. */
_Float128
__lgamma_negl (_Float128 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 L(1.0) / L(0.0);
_Float128 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. */
_Float128 x0_hi = lgamma_zeros[i][0], x0_lo = lgamma_zeros[i][1];
_Float128 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;
_Float128 xm = (-33 - 2 * j) * L(0.0625);
_Float128 x_adj = x - xm;
size_t deg = poly_deg[j];
size_t end = poly_end[j];
_Float128 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)). */
_Float128 x_idiff = fabsl (xn - x), x0_idiff = fabsl (xn - x0_hi - x0_lo);
_Float128 log_sinpi_ratio;
if (x0_idiff < x_idiff * L(0.5))
/* 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. */
_Float128 x0diff2 = ((i & 1) == 0 ? xdiff : -xdiff) * L(0.5);
_Float128 sx0d2 = lg_sinpi (x0diff2);
_Float128 cx0d2 = lg_cospi (x0diff2);
log_sinpi_ratio = __log1pl (2 * sx0d2
* (-sx0d2 + cx0d2 * lg_cotpi (x_idiff)));
}
_Float128 log_gamma_ratio;
_Float128 y0 = 1 - x0_hi;
_Float128 y0_eps = -x0_hi + (1 - y0) - x0_lo;
_Float128 y = 1 - x;
_Float128 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. */
_Float128 log_gamma_adj = 0;
if (i < 20)
{
int n_up = (21 - i) / 2;
_Float128 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;
_Float128 prodm1 = __lgamma_productl (xdiff, y - n_up, y_eps, n_up);
log_gamma_adj = -__log1pl (prodm1);
}
_Float128 log_gamma_high
= (xdiff * __log1pl ((y0 - e_hi - e_lo + y0_eps) / e_hi)
+ (y - L(0.5) + y_eps) * __log1pl (xdiff / y) + log_gamma_adj);
/* Compute the sum of (B_2k / 2k(2k-1))(Y0^-(2k-1) - Y^-(2k-1)). */
_Float128 y0r = 1 / y0, yr = 1 / y;
_Float128 y0r2 = y0r * y0r, yr2 = yr * yr;
_Float128 rdiff = -xdiff / (y * y0);
_Float128 bterm[NCOEFF];
_Float128 dlast = rdiff, elast = rdiff * yr * (yr + y0r);
bterm[0] = dlast * lgamma_coeff[0];
for (size_t j = 1; j < NCOEFF; j++)
{
_Float128 dnext = dlast * y0r2 + elast;
_Float128 enext = elast * yr2;
bterm[j] = dnext * lgamma_coeff[j];
dlast = dnext;
elast = enext;
}
_Float128 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;
}