1 /*
2 (C) Copyright 2001,2006,
3 International Business Machines Corporation,
4 Sony Computer Entertainment, Incorporated,
5 Toshiba Corporation,
6
7 All rights reserved.
8
9 Redistribution and use in source and binary forms, with or without
10 modification, are permitted provided that the following conditions are met:
11
12 * Redistributions of source code must retain the above copyright notice,
13 this list of conditions and the following disclaimer.
14 * Redistributions in binary form must reproduce the above copyright
15 notice, this list of conditions and the following disclaimer in the
16 documentation and/or other materials provided with the distribution.
17 * Neither the names of the copyright holders nor the names of their
18 contributors may be used to endorse or promote products derived from this
19 software without specific prior written permission.
20
21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
24 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
25 OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33 #ifndef _FMODF_H_
34 #define _FMODF_H_ 1
35
36 #include <errno.h>
37 #include <spu_intrinsics.h>
38 #include "headers/vec_literal.h"
39
40 #include "fabsf.h"
41
42 /*
43 * FUNCTION
44 * float _fmodf(float x, float y)
45 *
46 * DESCRIPTION
47 * The _fmodf subroutine computes the remainder of
48 * dividing x by y. The return value is x - n*y, where n is
49 * the quotient of x/y, rounded towards zero.
50 *
51 * The full range form (default) provides fmod computation on
52 * all IEEE floating point values (excluding floating overflow
53 * or underflow).
54 *
55 * The limited range form (selected by defining FMODF_INTEGER_RANGE)
56 * compute fmod of all floating-point x/y values in the 32-bit
57 * signed integer range. Values outside this range get clamped.
58 */
59
_fmodf(float x,float y)60 static __inline float _fmodf(float x, float y)
61 {
62 #ifdef FMODF_INTEGER_RANGE
63 /* 32-BIT INTEGER DYNAMIC RANGE
64 */
65 float abs_y;
66 float quotient;
67
68 abs_y = _fabsf(y);
69 quotient = x/abs_y;
70
71 return (abs_y*(quotient - ((float)((int)quotient))));
72
73 #else /* !FMODF_INTEGER_RANGE */
74 /* FULL FLOATING-POINT RANGE
75 */
76 int n;
77 vec_uint4 vx, vy, z;
78 vec_uint4 abs_x, abs_y;
79 vec_uint4 exp_x, exp_y;
80 vec_uint4 zero_x, zero_y;
81 vec_uint4 logb_x, logb_y;
82 vec_uint4 mant_x, mant_y;
83 vec_uint4 result, result0, resultx, cnt, sign;
84 vec_uint4 sign_mask = VEC_SPLAT_U32(0x80000000);
85 vec_uint4 implied_1 = VEC_SPLAT_U32(0x00800000);
86 vec_uint4 mant_mask = VEC_SPLAT_U32(0x007FFFFF);
87 vec_uint4 domain;
88 vec_int4 verrno;
89 vec_float4 vc = { 0.0, 0.0, 0.0, 0.0 };
90 vec_int4 fail = { EDOM, EDOM, EDOM, EDOM };
91
92 vx = (vec_uint4)spu_promote(x, 0);
93 vy = (vec_uint4)spu_promote(y, 0);
94
95 abs_x = spu_andc(vx, sign_mask);
96 abs_y = spu_andc(vy, sign_mask);
97
98 sign = spu_and(vx, sign_mask);
99
100 /* Determine ilogb of abs_x and abs_y and
101 * extract the mantissas (mant_x, mant_y)
102 */
103 exp_x = spu_rlmask(abs_x, -23);
104 exp_y = spu_rlmask(abs_y, -23);
105
106 resultx = spu_cmpgt(abs_y, abs_x);
107
108 zero_x = spu_cmpeq(exp_x, 0);
109 zero_y = spu_cmpeq(exp_y, 0);
110
111 logb_x = spu_add(exp_x, -127);
112 logb_y = spu_add(exp_y, -127);
113
114 mant_x = spu_andc(spu_sel(implied_1, abs_x, mant_mask), zero_x);
115 mant_y = spu_andc(spu_sel(implied_1, abs_y, mant_mask), zero_y);
116
117 /* Compute fixed point fmod of mant_x and mant_y. Set the flag,
118 * result0, to all ones if we detect that the final result is
119 * ever 0.
120 */
121 result0 = spu_or(zero_x, zero_y);
122
123 n = spu_extract(spu_sub(logb_x, logb_y), 0);
124
125 while (n-- > 0) {
126 z = spu_sub(mant_x, mant_y);
127
128 result0 = spu_or(spu_cmpeq(z, 0), result0);
129
130 mant_x = spu_sel(spu_add(mant_x, mant_x), spu_add(z, z),
131 spu_cmpgt((vec_int4)z, -1));
132 }
133
134 z = spu_sub(mant_x, mant_y);
135 mant_x = spu_sel(mant_x, z, spu_cmpgt((vec_int4)z, -1));
136
137 result0 = spu_or(spu_cmpeq(mant_x, 0), result0);
138
139 /* Convert the result back to floating point and restore
140 * the sign. If we flagged the result to be zero (result0),
141 * zero it. If we flagged the result to equal its input x,
142 * (resultx) then return x.
143 */
144 cnt = spu_add(spu_cntlz(mant_x), -8);
145
146 mant_x = spu_rl(spu_andc(mant_x, implied_1), (vec_int4)cnt);
147
148 exp_y = spu_sub(exp_y, cnt);
149 result0 = spu_orc(result0, spu_cmpgt((vec_int4)exp_y, 0)); /* zero denorm results */
150 exp_y = spu_rl(exp_y, 23);
151
152
153 result = spu_sel(exp_y, spu_or(sign, mant_x), VEC_SPLAT_U32(0x807FFFFF));
154
155 result = spu_sel(spu_andc(result, spu_rlmask(result0, -1)), vx,
156 resultx);
157
158 #ifndef _IEEE_LIBM
159 /*
160 * If y is zero, set errno to EDOM
161 */
162 domain = spu_cmpeq(vc, (vec_float4) vy);
163 verrno = spu_splats(errno);
164 errno = spu_extract(spu_sel(verrno, fail, (vector unsigned int) domain), 0);
165 #endif
166
167 return (spu_extract((vec_float4)result, 0));
168 #endif /* FMODF_INTEGER_RANGE */
169 }
170 #endif /* _FMODF_H_ */
171
