xref: /llvm-project/libclc/generic/lib/math/sinh.cl (revision 78b5bb702fe97fe85f66d72598d0dfa7c49fe001)
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#include <clc/clcmacro.h>
25#include <clc/math/math.h>
26#include <clc/math/tables.h>
27
28_CLC_OVERLOAD _CLC_DEF float sinh(float x)
29{
30    // After dealing with special cases the computation is split into regions as follows.
31    // abs(x) >= max_sinh_arg:
32    // sinh(x) = sign(x)*Inf
33    // abs(x) >= small_threshold:
34    // sinh(x) = sign(x)*exp(abs(x))/2 computed using the splitexp and scaleDouble functions as for exp_amd().
35    // abs(x) < small_threshold:
36    // compute p = exp(y) - 1 and then z = 0.5*(p+(p/(p+1.0)))
37    // sinh(x) is then sign(x)*z.
38
39    const float max_sinh_arg = 0x1.65a9fap+6f;
40    const float small_threshold = 0x1.0a2b24p+3f;
41
42    uint ux = as_uint(x);
43    uint aux = ux & EXSIGNBIT_SP32;
44    uint xs = ux ^ aux;
45    float y = as_float(aux);
46
47    // We find the integer part y0 of y and the increment dy = y - y0. We then compute
48    // z = sinh(y) = sinh(y0)cosh(dy) + cosh(y0)sinh(dy)
49    // where sinh(y0) and cosh(y0) are tabulated above.
50    int ind = (int) y;
51    ind = (uint)ind > 36U ? 0 : ind;
52
53    float dy = y - ind;
54    float dy2 = dy * dy;
55
56    float sdy = mad(dy2,
57                    mad(dy2,
58                        mad(dy2,
59                            mad(dy2,
60                                mad(dy2,
61                                    mad(dy2, 0.7746188980094184251527126e-12f, 0.160576793121939886190847e-9f),
62                                    0.250521176994133472333666e-7f),
63                                0.275573191913636406057211e-5f),
64                            0.198412698413242405162014e-3f),
65                         0.833333333333329931873097e-2f),
66                    0.166666666666666667013899e0f);
67    sdy = mad(sdy, dy*dy2, dy);
68
69    float cdy = mad(dy2,
70                    mad(dy2,
71                        mad(dy2,
72                            mad(dy2,
73                                mad(dy2,
74                                    mad(dy2, 0.1163921388172173692062032e-10f, 0.208744349831471353536305e-8f),
75                                    0.275573350756016588011357e-6f),
76                                0.248015872460622433115785e-4f),
77                            0.138888888889814854814536e-2f),
78                        0.416666666666660876512776e-1f),
79                    0.500000000000000005911074e0f);
80    cdy = mad(cdy, dy2, 1.0f);
81
82    float2 tv = USE_TABLE(sinhcosh_tbl, ind);
83    float z = mad(tv.s1, sdy, tv.s0 * cdy);
84    z = as_float(xs | as_uint(z));
85
86    // When y is large enough so that the negative exponential is negligible,
87    // so sinh(y) is approximated by sign(x)*exp(y)/2.
88    float t = exp(y - 0x1.62e500p-1f);
89    float zsmall = mad(0x1.a0210ep-18f, t, t);
90    zsmall = as_float(xs | as_uint(zsmall));
91    z = y >= small_threshold ? zsmall : z;
92
93    // Corner cases
94    float zinf = as_float(PINFBITPATT_SP32 | xs);
95    z = y >= max_sinh_arg ? zinf : z;
96    z = aux > PINFBITPATT_SP32 | aux < 0x38800000U ? x : z;
97
98    return z;
99}
100
101_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, sinh, float);
102
103#ifdef cl_khr_fp64
104#pragma OPENCL EXTENSION cl_khr_fp64 : enable
105
106_CLC_OVERLOAD _CLC_DEF double sinh(double x)
107{
108    // After dealing with special cases the computation is split into
109    // regions as follows:
110    //
111    // abs(x) >= max_sinh_arg:
112    // sinh(x) = sign(x)*Inf
113    //
114    // abs(x) >= small_threshold:
115    // sinh(x) = sign(x)*exp(abs(x))/2 computed using the
116    // splitexp and scaleDouble functions as for exp_amd().
117    //
118    // abs(x) < small_threshold:
119    // compute p = exp(y) - 1 and then z = 0.5*(p+(p/(p+1.0)))
120    // sinh(x) is then sign(x)*z.
121
122    const double max_sinh_arg = 7.10475860073943977113e+02; // 0x408633ce8fb9f87e
123
124    // This is where exp(-x) is insignificant compared to exp(x) = ln(2^27)
125    const double small_threshold = 0x1.2b708872320e2p+4;
126
127    double y = fabs(x);
128
129    // In this range we find the integer part y0 of y
130    // and the increment dy = y - y0. We then compute
131    // z = sinh(y) = sinh(y0)cosh(dy) + cosh(y0)sinh(dy)
132    // where sinh(y0) and cosh(y0) are obtained from tables
133
134    int ind = min((int)y, 36);
135    double dy = y - ind;
136    double dy2 = dy * dy;
137
138    double sdy = dy * dy2 *
139	         fma(dy2,
140		     fma(dy2,
141			 fma(dy2,
142			     fma(dy2,
143				 fma(dy2,
144				     fma(dy2, 0.7746188980094184251527126e-12, 0.160576793121939886190847e-9),
145				     0.250521176994133472333666e-7),
146				 0.275573191913636406057211e-5),
147			     0.198412698413242405162014e-3),
148			 0.833333333333329931873097e-2),
149		     0.166666666666666667013899e0);
150
151    double cdy = dy2 * fma(dy2,
152	                   fma(dy2,
153			       fma(dy2,
154				   fma(dy2,
155				       fma(dy2,
156					   fma(dy2, 0.1163921388172173692062032e-10, 0.208744349831471353536305e-8),
157					   0.275573350756016588011357e-6),
158				       0.248015872460622433115785e-4),
159				   0.138888888889814854814536e-2),
160			       0.416666666666660876512776e-1),
161			   0.500000000000000005911074e0);
162
163    // At this point sinh(dy) is approximated by dy + sdy.
164    // Shift some significant bits from dy to sdy.
165    double sdy1 = as_double(as_ulong(dy) & 0xfffffffff8000000UL);
166    double sdy2 = sdy + (dy - sdy1);
167
168    double2 tv = USE_TABLE(cosh_tbl, ind);
169    double cl = tv.s0;
170    double ct = tv.s1;
171    tv = USE_TABLE(sinh_tbl, ind);
172    double sl = tv.s0;
173    double st = tv.s1;
174
175    double z = fma(cl, sdy1, fma(sl, cdy, fma(cl, sdy2, fma(ct, sdy1, fma(st, cdy, ct*sdy2)) + st))) + sl;
176
177    // Other cases
178    z = (y < 0x1.0p-28) | isnan(x) | isinf(x) ? y : z;
179
180    double t = exp(y - 0x1.62e42fefa3800p-1);
181    t = fma(t, -0x1.ef35793c76641p-45, t);
182    z = y >= small_threshold ? t : z;
183    z = y >= max_sinh_arg ? as_double(PINFBITPATT_DP64) : z;
184
185    return copysign(z, x);
186}
187
188_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, sinh, double)
189
190#endif
191
192#ifdef cl_khr_fp16
193
194#pragma OPENCL EXTENSION cl_khr_fp16 : enable
195
196_CLC_DEFINE_UNARY_BUILTIN_FP16(sinh)
197
198#endif
199