1/*
2 * Copyright 2017 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is 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
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: AMD
23 *
24 */
25
26#include "os_types.h"
27#include "dcn_calc_math.h"
28
29#define isNaN(number) ((number) != (number))
30
31/*
32 * NOTE:
33 *   This file is gcc-parseable HW gospel, coming straight from HW engineers.
34 *
35 * It doesn't adhere to Linux kernel style and sometimes will do things in odd
36 * ways. Unless there is something clearly wrong with it the code should
37 * remain as-is as it provides us with a guarantee from HW that it is correct.
38 */
39
40float dcn_bw_mod(const float arg1, const float arg2)
41{
42	if (isNaN(arg1))
43		return arg2;
44	if (isNaN(arg2))
45		return arg1;
46	return arg1 - arg1 * ((int) (arg1 / arg2));
47}
48
49float dcn_bw_min2(const float arg1, const float arg2)
50{
51	if (isNaN(arg1))
52		return arg2;
53	if (isNaN(arg2))
54		return arg1;
55	return arg1 < arg2 ? arg1 : arg2;
56}
57
58unsigned int dcn_bw_max(const unsigned int arg1, const unsigned int arg2)
59{
60	return arg1 > arg2 ? arg1 : arg2;
61}
62float dcn_bw_max2(const float arg1, const float arg2)
63{
64	if (isNaN(arg1))
65		return arg2;
66	if (isNaN(arg2))
67		return arg1;
68	return arg1 > arg2 ? arg1 : arg2;
69}
70
71float dcn_bw_floor2(const float arg, const float significance)
72{
73	ASSERT(significance != 0);
74
75	return ((int) (arg / significance)) * significance;
76}
77float dcn_bw_floor(const float arg)
78{
79	return ((int) (arg));
80}
81
82float dcn_bw_ceil(const float arg)
83{
84	return (int) (arg + 0.99999);
85}
86
87float dcn_bw_ceil2(const float arg, const float significance)
88{
89	ASSERT(significance != 0);
90
91	return ((int) (arg / significance + 0.99999)) * significance;
92}
93
94float dcn_bw_max3(float v1, float v2, float v3)
95{
96	return v3 > dcn_bw_max2(v1, v2) ? v3 : dcn_bw_max2(v1, v2);
97}
98
99float dcn_bw_max5(float v1, float v2, float v3, float v4, float v5)
100{
101	return dcn_bw_max3(v1, v2, v3) > dcn_bw_max2(v4, v5) ? dcn_bw_max3(v1, v2, v3) : dcn_bw_max2(v4, v5);
102}
103
104float dcn_bw_pow(float a, float exp)
105{
106	float temp;
107	/*ASSERT(exp == (int)exp);*/
108	if ((int)exp == 0)
109		return 1;
110	temp = dcn_bw_pow(a, (int)(exp / 2));
111	if (((int)exp % 2) == 0) {
112		return temp * temp;
113	} else {
114		if ((int)exp > 0)
115			return a * temp * temp;
116		else
117			return (temp * temp) / a;
118	}
119}
120
121double dcn_bw_fabs(double a)
122{
123	if (a > 0)
124		return (a);
125	else
126		return (-a);
127}
128
129
130float dcn_bw_log(float a, float b)
131{
132	int * const exp_ptr = (int *)(&a);
133	int x = *exp_ptr;
134	const int log_2 = ((x >> 23) & 255) - 128;
135	x &= ~(255 << 23);
136	x += 127 << 23;
137	*exp_ptr = x;
138
139	a = ((-1.0f / 3) * a + 2) * a - 2.0f / 3;
140
141	if (b > 2.00001 || b < 1.99999)
142		return (a + log_2) / dcn_bw_log(b, 2);
143	else
144		return (a + log_2);
145}
146