1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
/* -------------------------------------------------------------- */
/* (C)Copyright 2006,2007, */
/* International Business Machines Corporation */
/* All Rights Reserved. */
/* */
/* Redistribution and use in source and binary forms, with or */
/* without modification, are permitted provided that the */
/* following conditions are met: */
/* */
/* - Redistributions of source code must retain the above copyright*/
/* notice, this list of conditions and the following disclaimer. */
/* */
/* - Redistributions in binary form must reproduce the above */
/* copyright notice, this list of conditions and the following */
/* disclaimer in the documentation and/or other materials */
/* provided with the distribution. */
/* */
/* - Neither the name of IBM Corporation nor the names of its */
/* contributors may be used to endorse or promote products */
/* derived from this software without specific prior written */
/* permission. */
/* Redistributions of source code must retain the above copyright */
/* notice, this list of conditions and the following disclaimer. */
/* */
/* Redistributions in binary form must reproduce the above */
/* copyright notice, this list of conditions and the following */
/* disclaimer in the documentation and/or other materials */
/* provided with the distribution. */
/* */
/* Neither the name of IBM Corporation nor the names of its */
/* contributors may be used to endorse or promote products */
/* derived from this software without specific prior written */
/* permission. */
/* */
/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND */
/* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, */
/* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
/* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE */
/* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR */
/* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */
/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT */
/* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; */
/* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) */
/* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */
/* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR */
/* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */
/* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
/* -------------------------------------------------------------- */
/* PROLOG END TAG zYx */
#ifdef __SPU__
#ifndef _NEXTAFTERF4_H_
#define _NEXTAFTERF4_H_ 1
#include <spu_intrinsics.h>
/*
* FUNCTION
* vector float _nextafterf4(vector float x, vector float y)
*
* DESCRIPTION
* The nextafterf4 function returns a vector containing the next representable
* floating-point number after the element of x, in the direction of the
* corresponding element y.
*
* Special Cases:
* - Infinity and NaN are not supported in single-precision on SPU. They are treated
* as normal numbers.
* - x != y, and result = 0 is considered an underflow.
*
*
*/
static __inline vector float _nextafterf4(vector float x, vector float y)
{
vec_float4 n1ulp = (vec_float4)spu_splats(0x80000001);
vec_float4 zerof = spu_splats(0.0f);
vec_int4 one = spu_splats(1);
vec_uint4 xlt0, xgty, xeqy, xeq0;
vec_int4 xint;
vec_int4 delta, deltap1;
vec_float4 result;
/*
* The idea here is to treat x as a signed int value, which allows us to
* add or subtact one to/from it to get the next representable value.
*/
xeq0 = spu_cmpeq(x, zerof);
xlt0 = spu_cmpgt(zerof, x);
xeqy = spu_cmpeq(x, y);
xgty = spu_cmpgt(x, y);
/* If x = -0.0, set x = 0.0 */
x = spu_andc(x, (vec_float4)xeq0);
xint = (vec_int4)x;
/* Determine value to add to x */
delta = (vec_int4)spu_xor(xgty, xlt0);
deltap1 = spu_add(delta,one);
delta = spu_sel(deltap1, delta, (vec_uint4)delta);
xint = spu_add(xint, delta);
/* Fix the case of x = 0, and answer should be -1 ulp */
result = spu_sel((vec_float4)xint, n1ulp, spu_and((vec_uint4)delta, xeq0));
/*
* Special Cases
*/
/* x = y */
result = spu_sel(result, y, xeqy);
return result;
}
#endif /* _NEXTAFTERF4_H_ */
#endif /* __SPU__ */
|
