about summary refs log tree commit diff
path: root/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
diff options
context:
space:
mode:
authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /sysdeps/ieee754/ldbl-128ibm/k_sinl.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
downloadglibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz
glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.xz
glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.zip
2.5-18.1
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/k_sinl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/k_sinl.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sinl.c b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
new file mode 100644
index 0000000000..24cb551b6e
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
@@ -0,0 +1,150 @@
+/* Quad-precision floating point sine on <-pi/4,pi/4>.
+   Copyright (C) 1999,2004,2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jakub Jelinek <jj@ultra.linux.cz>
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include "math.h"
+#include "math_private.h"
+
+static const long double c[] = {
+#define ONE c[0]
+ 1.00000000000000000000000000000000000E+00L, /* 3fff0000000000000000000000000000 */
+
+/* cos x ~ ONE + x^2 ( SCOS1 + SCOS2 * x^2 + ... + SCOS4 * x^6 + SCOS5 * x^8 )
+   x in <0,1/256>  */
+#define SCOS1 c[1]
+#define SCOS2 c[2]
+#define SCOS3 c[3]
+#define SCOS4 c[4]
+#define SCOS5 c[5]
+-5.00000000000000000000000000000000000E-01L, /* bffe0000000000000000000000000000 */
+ 4.16666666666666666666666666556146073E-02L, /* 3ffa5555555555555555555555395023 */
+-1.38888888888888888888309442601939728E-03L, /* bff56c16c16c16c16c16a566e42c0375 */
+ 2.48015873015862382987049502531095061E-05L, /* 3fefa01a01a019ee02dcf7da2d6d5444 */
+-2.75573112601362126593516899592158083E-07L, /* bfe927e4f5dce637cb0b54908754bde0 */
+
+/* sin x ~ ONE * x + x^3 ( SIN1 + SIN2 * x^2 + ... + SIN7 * x^12 + SIN8 * x^14 )
+   x in <0,0.1484375>  */
+#define SIN1 c[6]
+#define SIN2 c[7]
+#define SIN3 c[8]
+#define SIN4 c[9]
+#define SIN5 c[10]
+#define SIN6 c[11]
+#define SIN7 c[12]
+#define SIN8 c[13]
+-1.66666666666666666666666666666666538e-01L, /* bffc5555555555555555555555555550 */
+ 8.33333333333333333333333333307532934e-03L, /* 3ff811111111111111111111110e7340 */
+-1.98412698412698412698412534478712057e-04L, /* bff2a01a01a01a01a01a019e7a626296 */
+ 2.75573192239858906520896496653095890e-06L, /* 3fec71de3a556c7338fa38527474b8f5 */
+-2.50521083854417116999224301266655662e-08L, /* bfe5ae64567f544e16c7de65c2ea551f */
+ 1.60590438367608957516841576404938118e-10L, /* 3fde6124613a811480538a9a41957115 */
+-7.64716343504264506714019494041582610e-13L, /* bfd6ae7f3d5aef30c7bc660b060ef365 */
+ 2.81068754939739570236322404393398135e-15L, /* 3fce9510115aabf87aceb2022a9a9180 */
+
+/* sin x ~ ONE * x + x^3 ( SSIN1 + SSIN2 * x^2 + ... + SSIN4 * x^6 + SSIN5 * x^8 )
+   x in <0,1/256>  */
+#define SSIN1 c[14]
+#define SSIN2 c[15]
+#define SSIN3 c[16]
+#define SSIN4 c[17]
+#define SSIN5 c[18]
+-1.66666666666666666666666666666666659E-01L, /* bffc5555555555555555555555555555 */
+ 8.33333333333333333333333333146298442E-03L, /* 3ff81111111111111111111110fe195d */
+-1.98412698412698412697726277416810661E-04L, /* bff2a01a01a01a01a019e7121e080d88 */
+ 2.75573192239848624174178393552189149E-06L, /* 3fec71de3a556c640c6aaa51aa02ab41 */
+-2.50521016467996193495359189395805639E-08L, /* bfe5ae644ee90c47dc71839de75b2787 */
+};
+
+#define SINCOSL_COS_HI 0
+#define SINCOSL_COS_LO 1
+#define SINCOSL_SIN_HI 2
+#define SINCOSL_SIN_LO 3
+extern const long double __sincosl_table[];
+
+long double
+__kernel_sinl(long double x, long double y, int iy)
+{
+  long double h, l, z, sin_l, cos_l_m1;
+  int64_t ix;
+  u_int32_t tix, hix, index;
+  GET_LDOUBLE_MSW64 (ix, x);
+  tix = ((u_int64_t)ix) >> 32;
+  tix &= ~0x80000000;			/* tix = |x|'s high 32 bits */
+  if (tix < 0x3fc30000)			/* |x| < 0.1484375 */
+    {
+      /* Argument is small enough to approximate it by a Chebyshev
+	 polynomial of degree 17.  */
+      if (tix < 0x3c600000)		/* |x| < 2^-57 */
+	if (!((int)x)) return x;	/* generate inexact */
+      z = x * x;
+      return x + (x * (z*(SIN1+z*(SIN2+z*(SIN3+z*(SIN4+
+		       z*(SIN5+z*(SIN6+z*(SIN7+z*SIN8)))))))));
+    }
+  else
+    {
+      /* So that we don't have to use too large polynomial,  we find
+	 l and h such that x = l + h,  where fabsl(l) <= 1.0/256 with 83
+	 possible values for h.  We look up cosl(h) and sinl(h) in
+	 pre-computed tables,  compute cosl(l) and sinl(l) using a
+	 Chebyshev polynomial of degree 10(11) and compute
+	 sinl(h+l) = sinl(h)cosl(l) + cosl(h)sinl(l).  */
+      int six = tix;
+      tix = ((six - 0x3ff00000) >> 4) + 0x3fff0000;
+      index = 0x3ffe - (tix >> 16);
+      hix = (tix + (0x200 << index)) & (0xfffffc00 << index);
+      x = fabsl (x);
+      switch (index)
+	{
+	case 0: index = ((45 << 10) + hix - 0x3ffe0000) >> 8; break;
+	case 1: index = ((13 << 11) + hix - 0x3ffd0000) >> 9; break;
+	default:
+	case 2: index = (hix - 0x3ffc3000) >> 10; break;
+	}
+      hix = (hix << 4) & 0x3fffffff;
+/*
+    The following should work for double but generates the wrong index.
+    For now the code above converts double to ieee extended to compute
+    the index back to double for the h value. 
+    
+      index = 0x3fe - (tix >> 20);
+      hix = (tix + (0x2000 << index)) & (0xffffc000 << index);
+      x = fabsl (x);
+      switch (index)
+	{
+	case 0: index = ((45 << 14) + hix - 0x3fe00000) >> 12; break;
+	case 1: index = ((13 << 15) + hix - 0x3fd00000) >> 13; break;
+	default:
+	case 2: index = (hix - 0x3fc30000) >> 14; break;
+	}
+*/
+      SET_LDOUBLE_WORDS64(h, ((u_int64_t)hix) << 32, 0);
+      if (iy)
+	l = y - (h - x);
+      else
+	l = x - h;
+      z = l * l;
+      sin_l = l*(ONE+z*(SSIN1+z*(SSIN2+z*(SSIN3+z*(SSIN4+z*SSIN5)))));
+      cos_l_m1 = z*(SCOS1+z*(SCOS2+z*(SCOS3+z*(SCOS4+z*SCOS5))));
+      z = __sincosl_table [index + SINCOSL_SIN_HI]
+	  + (__sincosl_table [index + SINCOSL_SIN_LO]
+	     + (__sincosl_table [index + SINCOSL_SIN_HI] * cos_l_m1)
+	     + (__sincosl_table [index + SINCOSL_COS_HI] * sin_l));
+      return (ix < 0) ? -z : z;
+    }
+}