Mercurial > hg > CbC > CbC_gcc
comparison libquadmath/math/sinq.c @ 68:561a7518be6b
update gcc-4.6
author | Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> |
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date | Sun, 21 Aug 2011 07:07:55 +0900 |
parents | |
children | 04ced10e8804 |
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67:f6334be47118 | 68:561a7518be6b |
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1 /* s_sinl.c -- long double version of s_sin.c. | |
2 * Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz. | |
3 */ | |
4 | |
5 /* | |
6 * ==================================================== | |
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. | |
8 * | |
9 * Developed at SunPro, a Sun Microsystems, Inc. business. | |
10 * Permission to use, copy, modify, and distribute this | |
11 * software is freely granted, provided that this notice | |
12 * is preserved. | |
13 * ==================================================== | |
14 */ | |
15 | |
16 /* sinl(x) | |
17 * Return sine function of x. | |
18 * | |
19 * kernel function: | |
20 * __kernel_sinl ... sine function on [-pi/4,pi/4] | |
21 * __kernel_cosl ... cose function on [-pi/4,pi/4] | |
22 * __ieee754_rem_pio2l ... argument reduction routine | |
23 * | |
24 * Method. | |
25 * Let S,C and T denote the sin, cos and tan respectively on | |
26 * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2 | |
27 * in [-pi/4 , +pi/4], and let n = k mod 4. | |
28 * We have | |
29 * | |
30 * n sin(x) cos(x) tan(x) | |
31 * ---------------------------------------------------------- | |
32 * 0 S C T | |
33 * 1 C -S -1/T | |
34 * 2 -S -C T | |
35 * 3 -C S -1/T | |
36 * ---------------------------------------------------------- | |
37 * | |
38 * Special cases: | |
39 * Let trig be any of sin, cos, or tan. | |
40 * trig(+-INF) is NaN, with signals; | |
41 * trig(NaN) is that NaN; | |
42 * | |
43 * Accuracy: | |
44 * TRIG(x) returns trig(x) nearly rounded | |
45 */ | |
46 | |
47 #include "quadmath-imp.h" | |
48 | |
49 __float128 | |
50 sinq (__float128 x) | |
51 { | |
52 __float128 y[2],z=0.0Q; | |
53 int64_t n, ix; | |
54 | |
55 /* High word of x. */ | |
56 GET_FLT128_MSW64(ix,x); | |
57 | |
58 /* |x| ~< pi/4 */ | |
59 ix &= 0x7fffffffffffffffLL; | |
60 if(ix <= 0x3ffe921fb54442d1LL) | |
61 return __quadmath_kernel_sinq(x,z,0); | |
62 | |
63 /* sin(Inf or NaN) is NaN */ | |
64 else if (ix>=0x7fff000000000000LL) { | |
65 if (ix == 0x7fff000000000000LL) { | |
66 GET_FLT128_LSW64(n,x); | |
67 } | |
68 return x-x; | |
69 } | |
70 | |
71 /* argument reduction needed */ | |
72 else { | |
73 n = __quadmath_rem_pio2q(x,y); | |
74 switch(n&3) { | |
75 case 0: return __quadmath_kernel_sinq(y[0],y[1],1); | |
76 case 1: return __quadmath_kernel_cosq(y[0],y[1]); | |
77 case 2: return -__quadmath_kernel_sinq(y[0],y[1],1); | |
78 default: | |
79 return -__quadmath_kernel_cosq(y[0],y[1]); | |
80 } | |
81 } | |
82 } |