2 * Copyright (c) 2007 Steven G. Kargl
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 * $FreeBSD: head/lib/msun/src/s_tanl.c 240828 2012-09-22 15:38:29Z kargl $
30 * Limited testing on pseudorandom numbers drawn within [0:4e8] shows
31 * an accuracy of <= 1.5 ULP where 247024 values of x out of 40 million
32 * possibles resulted in tan(x) that exceeded 0.5 ULP (ie., 0.6%).
41 #include "math_private.h"
42 #if LDBL_MANT_DIG == 64
43 #include "../ld80/e_rem_pio2l.h"
44 #elif LDBL_MANT_DIG == 113
45 #include "../ld128/e_rem_pio2l.h"
47 #error "Unsupported long double format"
62 /* If x = +-0 or x is subnormal, then tan(x) = x. */
66 /* If x = NaN or Inf, then tan(x) = NaN. */
67 if (z.bits.exp == 32767)
68 return ((x - x) / (x - x));
72 /* Optimize the case where x is already within range. */
74 hi = __kernel_tanl(z.e, 0, 0);
75 RETURNI(s ? -hi : hi);
78 e0 = __ieee754_rem_pio2l(x, y);
85 hi = __kernel_tanl(hi, lo, 0);
89 hi = __kernel_tanl(hi, lo, 1);