1/*
2 * Copyright (c) 2014 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23#include <clc/clc.h>
24
25#include "math.h"
26#include "tables.h"
27#include "../clcmacro.h"
28
29_CLC_OVERLOAD _CLC_DEF float sinh(float x)
30{
31    // After dealing with special cases the computation is split into regions as follows.
32    // abs(x) >= max_sinh_arg:
33    // sinh(x) = sign(x)*Inf
34    // abs(x) >= small_threshold:
35    // sinh(x) = sign(x)*exp(abs(x))/2 computed using the splitexp and scaleDouble functions as for exp_amd().
36    // abs(x) < small_threshold:
37    // compute p = exp(y) - 1 and then z = 0.5*(p+(p/(p+1.0)))
38    // sinh(x) is then sign(x)*z.
39
40    const float max_sinh_arg = 0x1.65a9fap+6f;
41    const float small_threshold = 0x1.0a2b24p+3f;
42
43    uint ux = as_uint(x);
44    uint aux = ux & EXSIGNBIT_SP32;
45    uint xs = ux ^ aux;
46    float y = as_float(aux);
47
48    // We find the integer part y0 of y and the increment dy = y - y0. We then compute
49    // z = sinh(y) = sinh(y0)cosh(dy) + cosh(y0)sinh(dy)
50    // where sinh(y0) and cosh(y0) are tabulated above.
51    int ind = (int) y;
52    ind = (uint)ind > 36U ? 0 : ind;
53
54    float dy = y - ind;
55    float dy2 = dy * dy;
56
57    float sdy = mad(dy2,
58                    mad(dy2,
59                        mad(dy2,
60                            mad(dy2,
61                                mad(dy2,
62                                    mad(dy2, 0.7746188980094184251527126e-12f, 0.160576793121939886190847e-9f),
63                                    0.250521176994133472333666e-7f),
64                                0.275573191913636406057211e-5f),
65                            0.198412698413242405162014e-3f),
66                         0.833333333333329931873097e-2f),
67                    0.166666666666666667013899e0f);
68    sdy = mad(sdy, dy*dy2, dy);
69
70    float cdy = mad(dy2,
71                    mad(dy2,
72                        mad(dy2,
73                            mad(dy2,
74                                mad(dy2,
75                                    mad(dy2, 0.1163921388172173692062032e-10f, 0.208744349831471353536305e-8f),
76                                    0.275573350756016588011357e-6f),
77                                0.248015872460622433115785e-4f),
78                            0.138888888889814854814536e-2f),
79                        0.416666666666660876512776e-1f),
80                    0.500000000000000005911074e0f);
81    cdy = mad(cdy, dy2, 1.0f);
82
83    float2 tv = USE_TABLE(sinhcosh_tbl, ind);
84    float z = mad(tv.s1, sdy, tv.s0 * cdy);
85    z = as_float(xs | as_uint(z));
86
87    // When y is large enough so that the negative exponential is negligible,
88    // so sinh(y) is approximated by sign(x)*exp(y)/2.
89    float t = exp(y - 0x1.62e500p-1f);
90    float zsmall = mad(0x1.a0210ep-18f, t, t);
91    zsmall = as_float(xs | as_uint(zsmall));
92    z = y >= small_threshold ? zsmall : z;
93
94    // Corner cases
95    float zinf = as_float(PINFBITPATT_SP32 | xs);
96    z = y >= max_sinh_arg ? zinf : z;
97    z = aux > PINFBITPATT_SP32 | aux < 0x38800000U ? x : z;
98
99    return z;
100}
101
102_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, sinh, float);
103
104#ifdef cl_khr_fp64
105#pragma OPENCL EXTENSION cl_khr_fp64 : enable
106
107_CLC_OVERLOAD _CLC_DEF double sinh(double x)
108{
109    // After dealing with special cases the computation is split into
110    // regions as follows:
111    //
112    // abs(x) >= max_sinh_arg:
113    // sinh(x) = sign(x)*Inf
114    //
115    // abs(x) >= small_threshold:
116    // sinh(x) = sign(x)*exp(abs(x))/2 computed using the
117    // splitexp and scaleDouble functions as for exp_amd().
118    //
119    // abs(x) < small_threshold:
120    // compute p = exp(y) - 1 and then z = 0.5*(p+(p/(p+1.0)))
121    // sinh(x) is then sign(x)*z.
122
123    const double max_sinh_arg = 7.10475860073943977113e+02; // 0x408633ce8fb9f87e
124
125    // This is where exp(-x) is insignificant compared to exp(x) = ln(2^27)
126    const double small_threshold = 0x1.2b708872320e2p+4;
127
128    double y = fabs(x);
129
130    // In this range we find the integer part y0 of y
131    // and the increment dy = y - y0. We then compute
132    // z = sinh(y) = sinh(y0)cosh(dy) + cosh(y0)sinh(dy)
133    // where sinh(y0) and cosh(y0) are obtained from tables
134
135    int ind = min((int)y, 36);
136    double dy = y - ind;
137    double dy2 = dy * dy;
138
139    double sdy = dy * dy2 *
140	         fma(dy2,
141		     fma(dy2,
142			 fma(dy2,
143			     fma(dy2,
144				 fma(dy2,
145				     fma(dy2, 0.7746188980094184251527126e-12, 0.160576793121939886190847e-9),
146				     0.250521176994133472333666e-7),
147				 0.275573191913636406057211e-5),
148			     0.198412698413242405162014e-3),
149			 0.833333333333329931873097e-2),
150		     0.166666666666666667013899e0);
151
152    double cdy = dy2 * fma(dy2,
153	                   fma(dy2,
154			       fma(dy2,
155				   fma(dy2,
156				       fma(dy2,
157					   fma(dy2, 0.1163921388172173692062032e-10, 0.208744349831471353536305e-8),
158					   0.275573350756016588011357e-6),
159				       0.248015872460622433115785e-4),
160				   0.138888888889814854814536e-2),
161			       0.416666666666660876512776e-1),
162			   0.500000000000000005911074e0);
163
164    // At this point sinh(dy) is approximated by dy + sdy.
165    // Shift some significant bits from dy to sdy.
166    double sdy1 = as_double(as_ulong(dy) & 0xfffffffff8000000UL);
167    double sdy2 = sdy + (dy - sdy1);
168
169    double2 tv = USE_TABLE(cosh_tbl, ind);
170    double cl = tv.s0;
171    double ct = tv.s1;
172    tv = USE_TABLE(sinh_tbl, ind);
173    double sl = tv.s0;
174    double st = tv.s1;
175
176    double z = fma(cl, sdy1, fma(sl, cdy, fma(cl, sdy2, fma(ct, sdy1, fma(st, cdy, ct*sdy2)) + st))) + sl;
177
178    // Other cases
179    z = (y < 0x1.0p-28) | isnan(x) | isinf(x) ? y : z;
180
181    double t = exp(y - 0x1.62e42fefa3800p-1);
182    t = fma(t, -0x1.ef35793c76641p-45, t);
183    z = y >= small_threshold ? t : z;
184    z = y >= max_sinh_arg ? as_double(PINFBITPATT_DP64) : z;
185
186    return copysign(z, x);
187}
188
189_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, sinh, double)
190
191#endif
192