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authorRoland McGrath <roland@gnu.org>2006-01-28 00:15:15 +0000
committerRoland McGrath <roland@gnu.org>2006-01-28 00:15:15 +0000
commitf964490f3c4f094fd684960c2e98885b23e31376 (patch)
treee10f697bd55240b9be7a9c1a5109ee07893d3136 /sysdeps/ieee754/ldbl-128ibm/e_jnl.c
parentd421a7801d1bdfd8175e53a79068833ae4de56b1 (diff)
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2006-01-27 Dwayne Grant McConnell <decimal@us.ibm.com>cvs/fedora-glibc-20060130T0922
Jakub Jelinek <jakub@redhat.com> Roland McGrath <roland@redhat.com> Steven Munroe <sjmunroe@us.ibm.com> Alan Modra <amodra@bigpond.net.au> * sysdeps/powerpc/powerpc64/fpu/s_truncf.S: Comment fix. * sysdeps/powerpc/powerpc32/fpu/s_truncf.S: Likewise. * sysdeps/powerpc/powerpc64/fpu/s_llroundf.S: Likewise. * sysdeps/powerpc/fpu/libm-test-ulps: Update. * math/libm-test.inc (check_float_internal): Allow ulp <= 0.5. (erfc_test): Don't run erfcl (27.0L) test if erfcl (27.0L) is denormal. [TEST_LDOUBLE] (ceil_test, floor_test, llrint_test, llround_test, rint_test, round_test, trunc_test): Add new tests. * sysdeps/powerpc/powerpc32/fpu/s_copysignl.S: New file. * sysdeps/powerpc/powerpc32/fpu/s_fabs.S: New file. * sysdeps/powerpc/powerpc32/fpu/s_fabsl.S: New file. * sysdeps/powerpc/powerpc32/fpu/s_fdim.c: New file. * sysdeps/powerpc/powerpc32/fpu/s_fmax.S: New file. * sysdeps/powerpc/powerpc32/fpu/s_fmin.S: New file. * sysdeps/powerpc/powerpc32/fpu/s_isnan.c: New file. * sysdeps/powerpc/powerpc64/fpu/s_ceill.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_copysignl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_fabs.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_fabsl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_fdim.c: New file. * sysdeps/powerpc/powerpc64/fpu/s_floorl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_fmax.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_fmin.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_isnan.c: New file. * sysdeps/powerpc/powerpc64/fpu/s_llrintl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_llroundl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_lrintl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_lroundl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_nearbyintl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_rintl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_roundl.S: New file. * sysdeps/powerpc/powerpc64/fpu/s_truncl.S: New file. * sysdeps/unix/sysv/linux/powerpc/Implies: New file. * sysdeps/unix/sysv/linux/powerpc/powerpc64/fpu/Implies: New file. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/Implies: New file. * sysdeps/unix/sysv/linux/powerpc/configure.in: New file. * sysdeps/unix/sysv/linux/powerpc/configure: New file. * sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h (__LONG_DOUBLE_MATH_OPTIONAL): Define. (__NO_LONG_DOUBLE_MATH): Define. * sysdeps/unix/sysv/linux/powerpc/nldbl-abi.h: New file. * sysdeps/powerpc/fpu/s_isnan.c: Include math_ldbl_opt.h. * sysdeps/powerpc/powerpc64/fpu/s_ceil.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (ceill): Add compatibility symbols. * sysdeps/powerpc/powerpc64/fpu/s_copysign.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (copysignl): Add compatibility symbols. * sysdeps/powerpc/powerpc64/fpu/s_floor.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (floorl): Add compatibility symbols. * sysdeps/powerpc/powerpc64/fpu/s_llrint.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (llrintl, lrintl): Add compatibility symbols. * sysdeps/powerpc/powerpc64/fpu/s_llround.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (llroundl, lroundl): Add compatibility symbols. * sysdeps/powerpc/powerpc64/fpu/s_rint.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (rintl): Add compatibility symbols. * sysdeps/powerpc/powerpc64/fpu/s_round.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (roundl): Add compatibility symbols. * sysdeps/powerpc/powerpc64/fpu/s_trunc.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (truncl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_ceil.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (ceill): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_copysign.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (copysignl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_floor.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (floorl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_lrint.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (lrintl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_llrint.c: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (llrintl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_lround.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (lroundl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_rint.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (rintl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_round.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (roundl): Add compatibility symbols. * sysdeps/powerpc/powerpc32/fpu/s_trunc.S: Include math_ldbl_opt.h. [LONG_DOUBLE_COMPAT] (truncl): Add compatibility symbols. * misc/qefgcvt_r.c [LDBL_MIN_10_EXP == -291] (FLOAT_MIN_10_NORM): New. * sysdeps/powerpc/fpu/bits/mathdef.h (__NO_LONG_DOUBLE_MATH): Remove. * sysdeps/powerpc/Implies: Add ieee754/ldbl-128ibm. * sysdeps/powerpc/powerpc32/Implies: Remove powerpc/soft-fp. * sysdeps/ieee754/ldbl-128ibm/Makefile: New file. * sysdeps/ieee754/ldbl-128ibm/e_acoshl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_acosl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_asinl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_atan2l.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_atanhl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_coshl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_expl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_fmodl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_hypotl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_j0l.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_j1l.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_jnl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_lgammal_r.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_log10l.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_log2l.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_logl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_powl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_remainderl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_sinhl.c: New file. * sysdeps/ieee754/ldbl-128ibm/e_sqrtl.c: New file. * sysdeps/ieee754/ldbl-128ibm/ieee754.h: New file. * sysdeps/ieee754/ldbl-128ibm/k_cosl.c: New file. * sysdeps/ieee754/ldbl-128ibm/k_sincosl.c: New file. * sysdeps/ieee754/ldbl-128ibm/k_sinl.c: New file. * sysdeps/ieee754/ldbl-128ibm/k_tanl.c: New file. * sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c: New file. * sysdeps/ieee754/ldbl-128ibm/math_ldbl.h: New file. * sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c: New file. * sysdeps/ieee754/ldbl-128ibm/printf_fphex.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_asinhl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_atanl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_cbrtl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_cosl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_erfl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_expm1l.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_fabsl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_finitel.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_frexpl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_ilogbl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_isinfl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_isnanl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_log1pl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_logbl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_modfl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_remquol.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_rintl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_scalblnl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_signbitl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_sincosl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_sinl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_tanhl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_tanl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_truncl.c: New file. * sysdeps/ieee754/ldbl-128ibm/strtold_l.c: New file. * sysdeps/ieee754/ldbl-128ibm/t_sincosl.c: New file. * sysdeps/ieee754/ldbl-128ibm/w_expl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_copysignl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_floorl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_llrintl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_llroundl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_roundl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_ceill.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_lrintl.c: New file. * sysdeps/ieee754/ldbl-128ibm/s_lroundl.c: New file. * sysdeps/ieee754/ldbl-128/e_powl.c: Fix old comment.
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/e_jnl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/e_jnl.c402
1 files changed, 402 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
new file mode 100644
index 0000000..0eea745
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
@@ -0,0 +1,402 @@
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/* Modifications for 128-bit long double are
+ Copyright (C) 2001 Stephen L. Moshier <moshier@na-net.ornl.gov>
+ and are incorporated herein by permission of the author. The author
+ reserves the right to distribute this material elsewhere under different
+ copying permissions. These modifications are distributed here under
+ the following terms:
+
+ 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, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
+
+/*
+ * __ieee754_jn(n, x), __ieee754_yn(n, x)
+ * floating point Bessel's function of the 1st and 2nd kind
+ * of order n
+ *
+ * Special cases:
+ * y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;
+ * y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal.
+ * Note 2. About jn(n,x), yn(n,x)
+ * For n=0, j0(x) is called,
+ * for n=1, j1(x) is called,
+ * for n<x, forward recursion us used starting
+ * from values of j0(x) and j1(x).
+ * for n>x, a continued fraction approximation to
+ * j(n,x)/j(n-1,x) is evaluated and then backward
+ * recursion is used starting from a supposed value
+ * for j(n,x). The resulting value of j(0,x) is
+ * compared with the actual value to correct the
+ * supposed value of j(n,x).
+ *
+ * yn(n,x) is similar in all respects, except
+ * that forward recursion is used for all
+ * values of n>1.
+ *
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double
+#else
+static long double
+#endif
+ invsqrtpi = 5.6418958354775628694807945156077258584405E-1L,
+ two = 2.0e0L,
+ one = 1.0e0L,
+ zero = 0.0L;
+
+
+#ifdef __STDC__
+long double
+__ieee754_jnl (int n, long double x)
+#else
+long double
+__ieee754_jnl (n, x)
+ int n;
+ long double x;
+#endif
+{
+ u_int32_t se;
+ int32_t i, ix, sgn;
+ long double a, b, temp, di;
+ long double z, w;
+ ieee854_long_double_shape_type u;
+
+
+ /* J(-n,x) = (-1)^n * J(n, x), J(n, -x) = (-1)^n * J(n, x)
+ * Thus, J(-n,x) = J(n,-x)
+ */
+
+ u.value = x;
+ se = u.parts32.w0;
+ ix = se & 0x7fffffff;
+
+ /* if J(n,NaN) is NaN */
+ if (ix >= 0x7ff00000)
+ {
+ if ((u.parts32.w0 & 0xfffff) | u.parts32.w1
+ | (u.parts32.w2 & 0x7fffffff) | u.parts32.w3)
+ return x + x;
+ }
+
+ if (n < 0)
+ {
+ n = -n;
+ x = -x;
+ se ^= 0x80000000;
+ }
+ if (n == 0)
+ return (__ieee754_j0l (x));
+ if (n == 1)
+ return (__ieee754_j1l (x));
+ sgn = (n & 1) & (se >> 31); /* even n -- 0, odd n -- sign(x) */
+ x = fabsl (x);
+
+ if (x == 0.0L || ix >= 0x7ff00000) /* if x is 0 or inf */
+ b = zero;
+ else if ((long double) n <= x)
+ {
+ /* Safe to use J(n+1,x)=2n/x *J(n,x)-J(n-1,x) */
+ if (ix >= 0x52d00000)
+ { /* x > 2**302 */
+
+ /* ??? Could use an expansion for large x here. */
+
+ /* (x >> n**2)
+ * Jn(x) = cos(x-(2n+1)*pi/4)*sqrt(2/x*pi)
+ * Yn(x) = sin(x-(2n+1)*pi/4)*sqrt(2/x*pi)
+ * Let s=sin(x), c=cos(x),
+ * xn=x-(2n+1)*pi/4, sqt2 = sqrt(2),then
+ *
+ * n sin(xn)*sqt2 cos(xn)*sqt2
+ * ----------------------------------
+ * 0 s-c c+s
+ * 1 -s-c -c+s
+ * 2 -s+c -c-s
+ * 3 s+c c-s
+ */
+ long double s;
+ long double c;
+ __sincosl (x, &s, &c);
+ switch (n & 3)
+ {
+ case 0:
+ temp = c + s;
+ break;
+ case 1:
+ temp = -c + s;
+ break;
+ case 2:
+ temp = -c - s;
+ break;
+ case 3:
+ temp = c - s;
+ break;
+ }
+ b = invsqrtpi * temp / __ieee754_sqrtl (x);
+ }
+ else
+ {
+ a = __ieee754_j0l (x);
+ b = __ieee754_j1l (x);
+ for (i = 1; i < n; i++)
+ {
+ temp = b;
+ b = b * ((long double) (i + i) / x) - a; /* avoid underflow */
+ a = temp;
+ }
+ }
+ }
+ else
+ {
+ if (ix < 0x3e100000)
+ { /* x < 2**-29 */
+ /* x is tiny, return the first Taylor expansion of J(n,x)
+ * J(n,x) = 1/n!*(x/2)^n - ...
+ */
+ if (n >= 33) /* underflow, result < 10^-300 */
+ b = zero;
+ else
+ {
+ temp = x * 0.5;
+ b = temp;
+ for (a = one, i = 2; i <= n; i++)
+ {
+ a *= (long double) i; /* a = n! */
+ b *= temp; /* b = (x/2)^n */
+ }
+ b = b / a;
+ }
+ }
+ else
+ {
+ /* use backward recurrence */
+ /* x x^2 x^2
+ * J(n,x)/J(n-1,x) = ---- ------ ------ .....
+ * 2n - 2(n+1) - 2(n+2)
+ *
+ * 1 1 1
+ * (for large x) = ---- ------ ------ .....
+ * 2n 2(n+1) 2(n+2)
+ * -- - ------ - ------ -
+ * x x x
+ *
+ * Let w = 2n/x and h=2/x, then the above quotient
+ * is equal to the continued fraction:
+ * 1
+ * = -----------------------
+ * 1
+ * w - -----------------
+ * 1
+ * w+h - ---------
+ * w+2h - ...
+ *
+ * To determine how many terms needed, let
+ * Q(0) = w, Q(1) = w(w+h) - 1,
+ * Q(k) = (w+k*h)*Q(k-1) - Q(k-2),
+ * When Q(k) > 1e4 good for single
+ * When Q(k) > 1e9 good for double
+ * When Q(k) > 1e17 good for quadruple
+ */
+ /* determine k */
+ long double t, v;
+ long double q0, q1, h, tmp;
+ int32_t k, m;
+ w = (n + n) / (long double) x;
+ h = 2.0L / (long double) x;
+ q0 = w;
+ z = w + h;
+ q1 = w * z - 1.0L;
+ k = 1;
+ while (q1 < 1.0e17L)
+ {
+ k += 1;
+ z += h;
+ tmp = z * q1 - q0;
+ q0 = q1;
+ q1 = tmp;
+ }
+ m = n + n;
+ for (t = zero, i = 2 * (n + k); i >= m; i -= 2)
+ t = one / (i / x - t);
+ a = t;
+ b = one;
+ /* estimate log((2/x)^n*n!) = n*log(2/x)+n*ln(n)
+ * Hence, if n*(log(2n/x)) > ...
+ * single 8.8722839355e+01
+ * double 7.09782712893383973096e+02
+ * long double 1.1356523406294143949491931077970765006170e+04
+ * then recurrent value may overflow and the result is
+ * likely underflow to zero
+ */
+ tmp = n;
+ v = two / x;
+ tmp = tmp * __ieee754_logl (fabsl (v * tmp));
+
+ if (tmp < 1.1356523406294143949491931077970765006170e+04L)
+ {
+ for (i = n - 1, di = (long double) (i + i); i > 0; i--)
+ {
+ temp = b;
+ b *= di;
+ b = b / x - a;
+ a = temp;
+ di -= two;
+ }
+ }
+ else
+ {
+ for (i = n - 1, di = (long double) (i + i); i > 0; i--)
+ {
+ temp = b;
+ b *= di;
+ b = b / x - a;
+ a = temp;
+ di -= two;
+ /* scale b to avoid spurious overflow */
+ if (b > 1e100L)
+ {
+ a /= b;
+ t /= b;
+ b = one;
+ }
+ }
+ }
+ b = (t * __ieee754_j0l (x) / b);
+ }
+ }
+ if (sgn == 1)
+ return -b;
+ else
+ return b;
+}
+
+#ifdef __STDC__
+long double
+__ieee754_ynl (int n, long double x)
+#else
+long double
+__ieee754_ynl (n, x)
+ int n;
+ long double x;
+#endif
+{
+ u_int32_t se;
+ int32_t i, ix;
+ int32_t sign;
+ long double a, b, temp;
+ ieee854_long_double_shape_type u;
+
+ u.value = x;
+ se = u.parts32.w0;
+ ix = se & 0x7fffffff;
+
+ /* if Y(n,NaN) is NaN */
+ if (ix >= 0x7ff00000)
+ {
+ if ((u.parts32.w0 & 0xfffff) | u.parts32.w1
+ | (u.parts32.w2 & 0x7fffffff) | u.parts32.w3)
+ return x + x;
+ }
+ if (x <= 0.0L)
+ {
+ if (x == 0.0L)
+ return -HUGE_VALL + x;
+ if (se & 0x80000000)
+ return zero / (zero * x);
+ }
+ sign = 1;
+ if (n < 0)
+ {
+ n = -n;
+ sign = 1 - ((n & 1) << 1);
+ }
+ if (n == 0)
+ return (__ieee754_y0l (x));
+ if (n == 1)
+ return (sign * __ieee754_y1l (x));
+ if (ix >= 0x7ff00000)
+ return zero;
+ if (ix >= 0x52D00000)
+ { /* x > 2**302 */
+
+ /* ??? See comment above on the possible futility of this. */
+
+ /* (x >> n**2)
+ * Jn(x) = cos(x-(2n+1)*pi/4)*sqrt(2/x*pi)
+ * Yn(x) = sin(x-(2n+1)*pi/4)*sqrt(2/x*pi)
+ * Let s=sin(x), c=cos(x),
+ * xn=x-(2n+1)*pi/4, sqt2 = sqrt(2),then
+ *
+ * n sin(xn)*sqt2 cos(xn)*sqt2
+ * ----------------------------------
+ * 0 s-c c+s
+ * 1 -s-c -c+s
+ * 2 -s+c -c-s
+ * 3 s+c c-s
+ */
+ long double s;
+ long double c;
+ __sincosl (x, &s, &c);
+ switch (n & 3)
+ {
+ case 0:
+ temp = s - c;
+ break;
+ case 1:
+ temp = -s - c;
+ break;
+ case 2:
+ temp = -s + c;
+ break;
+ case 3:
+ temp = s + c;
+ break;
+ }
+ b = invsqrtpi * temp / __ieee754_sqrtl (x);
+ }
+ else
+ {
+ a = __ieee754_y0l (x);
+ b = __ieee754_y1l (x);
+ /* quit if b is -inf */
+ u.value = b;
+ se = u.parts32.w0 & 0xfff00000;
+ for (i = 1; i < n && se != 0xfff00000; i++)
+ {
+ temp = b;
+ b = ((long double) (i + i) / x) * b - a;
+ u.value = b;
+ se = u.parts32.w0 & 0xfff00000;
+ a = temp;
+ }
+ }
+ if (sign > 0)
+ return b;
+ else
+ return -b;
+}