1 /* -------------------------------------------------------------- */
2 /* (C)Copyright 2007,2008, */
3 /* International Business Machines Corporation */
4 /* All Rights Reserved. */
5 /* */
6 /* Redistribution and use in source and binary forms, with or */
7 /* without modification, are permitted provided that the */
8 /* following conditions are met: */
9 /* */
10 /* - Redistributions of source code must retain the above copyright*/
11 /* notice, this list of conditions and the following disclaimer. */
12 /* */
13 /* - Redistributions in binary form must reproduce the above */
14 /* copyright notice, this list of conditions and the following */
15 /* disclaimer in the documentation and/or other materials */
16 /* provided with the distribution. */
17 /* */
18 /* - Neither the name of IBM Corporation nor the names of its */
19 /* contributors may be used to endorse or promote products */
20 /* derived from this software without specific prior written */
21 /* permission. */
22 /* */
23 /* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND */
24 /* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, */
25 /* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
26 /* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE */
27 /* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR */
28 /* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */
29 /* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT */
30 /* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; */
31 /* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) */
32 /* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */
33 /* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR */
34 /* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */
35 /* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
36 /* -------------------------------------------------------------- */
37 /* PROLOG END TAG zYx */
38 #ifdef __SPU__
39 #ifndef _ATAN2D2_H_
40 #define _ATAN2D2_H_ 1
41
42 #include <spu_intrinsics.h>
43
44 #include "divd2.h"
45 #include "atand2.h"
46
47 /*
48 * FUNCTION
49 * vector double _atan2d2(vector double y, vector double x)
50 *
51 * DESCRIPTION
52 * The atan2d2 function returns a vector containing the angles
53 * whose tangets are y/x for the corresponding elements of the
54 * input vectors.
55 *
56 * The reason this function exists is to use the signs of the
57 * arguments to determine the quadrant of the result. Consider
58 * sin(x)/cos(x) on the domain (-pi, pi]. Four quadrants are
59 * defined by the signs of sin and cos on this domain.
60 *
61 * Special Cases:
62 * - If the corresponding elements of x and y are zero, the
63 * resulting element is undefined.
64 *
65 */
66
_atan2d2(vector double y,vector double x)67 static __inline vector double _atan2d2(vector double y, vector double x)
68 {
69 vec_uchar16 dup_even = ((vec_uchar16) { 0,1,2,3, 0,1,2,3, 8,9,10,11, 8,9,10,11 });
70 vector double pi = spu_splats(SM_PI);
71 vector unsigned long long ones = spu_splats(0xFFFFFFFFFFFFFFFFull);
72 vector unsigned long long quad1;
73 vector unsigned long long quad4;
74 vector double result;
75
76 vector unsigned long long xlt0;
77 vector unsigned long long yge0;
78 vector unsigned long long ylt0;
79
80 xlt0 = (vec_ullong2)spu_rlmaska((vec_int4)spu_shuffle(x,x,dup_even), 31);
81 ylt0 = (vec_ullong2)spu_rlmaska((vec_int4)spu_shuffle(y,y,dup_even), 31);
82 yge0 = spu_xor(ylt0, ones);
83
84 quad1 = spu_and(ylt0, xlt0);
85 quad4 = spu_and(yge0, xlt0);
86
87 result = _atand2(_divd2(y,x));
88
89 result = spu_sel(result, spu_sub(result, pi), quad1);
90 result = spu_sel(result, spu_add(result, pi), quad4);
91
92 return result;
93 }
94
95 #endif /* _ATAN2D2_H_ */
96 #endif /* __SPU__ */
97
