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 "dcn_calc_math.h"
 27
 28#define isNaN(number) ((number) != (number))
 29
 30/*
 31 * NOTE:
 32 *   This file is gcc-parseable HW gospel, coming straight from HW engineers.
 33 *
 34 * It doesn't adhere to Linux kernel style and sometimes will do things in odd
 35 * ways. Unless there is something clearly wrong with it the code should
 36 * remain as-is as it provides us with a guarantee from HW that it is correct.
 37 */
 38
 39float dcn_bw_mod(const float arg1, const float arg2)
 40{
 41	if (isNaN(arg1))
 42		return arg2;
 43	if (isNaN(arg2))
 44		return arg1;
 45	return arg1 - arg1 * ((int) (arg1 / arg2));
 46}
 47
 48float dcn_bw_min2(const float arg1, const float arg2)
 49{
 50	if (isNaN(arg1))
 51		return arg2;
 52	if (isNaN(arg2))
 53		return arg1;
 54	return arg1 < arg2 ? arg1 : arg2;
 55}
 56
 57unsigned int dcn_bw_max(const unsigned int arg1, const unsigned int arg2)
 58{
 59	return arg1 > arg2 ? arg1 : arg2;
 60}
 61float dcn_bw_max2(const float arg1, const float arg2)
 62{
 63	if (isNaN(arg1))
 64		return arg2;
 65	if (isNaN(arg2))
 66		return arg1;
 67	return arg1 > arg2 ? arg1 : arg2;
 68}
 69
 70float dcn_bw_floor2(const float arg, const float significance)
 71{
 72	if (significance == 0)
 73		return 0;
 74	return ((int) (arg / significance)) * significance;
 75}
 76float dcn_bw_floor(const float arg)
 77{
 78	return ((int) (arg));
 79}
 80
 81float dcn_bw_ceil(const float arg)
 82{
 83	float flr = dcn_bw_floor2(arg, 1);
 84
 85	return flr + 0.00001 >= arg ? arg : flr + 1;
 86}
 87
 88float dcn_bw_ceil2(const float arg, const float significance)
 89{
 90	float flr = dcn_bw_floor2(arg, significance);
 91	if (significance == 0)
 92		return 0;
 93	return flr + 0.00001 >= arg ? arg : flr + significance;
 94}
 95
 96float dcn_bw_max3(float v1, float v2, float v3)
 97{
 98	return v3 > dcn_bw_max2(v1, v2) ? v3 : dcn_bw_max2(v1, v2);
 99}
100
101float dcn_bw_max5(float v1, float v2, float v3, float v4, float v5)
102{
103	return dcn_bw_max3(v1, v2, v3) > dcn_bw_max2(v4, v5) ? dcn_bw_max3(v1, v2, v3) : dcn_bw_max2(v4, v5);
104}
105
106float dcn_bw_pow(float a, float exp)
107{
108	float temp;
109	/*ASSERT(exp == (int)exp);*/
110	if ((int)exp == 0)
111		return 1;
112	temp = dcn_bw_pow(a, (int)(exp / 2));
113	if (((int)exp % 2) == 0) {
114		return temp * temp;
115	} else {
116		if ((int)exp > 0)
117			return a * temp * temp;
118		else
119			return (temp * temp) / a;
120	}
121}
122
123double dcn_bw_fabs(double a)
124{
125	if (a > 0)
126		return (a);
127	else
128		return (-a);
129}
130
131
132float dcn_bw_log(float a, float b)
133{
134	int * const exp_ptr = (int *)(&a);
135	int x = *exp_ptr;
136	const int log_2 = ((x >> 23) & 255) - 128;
137	x &= ~(255 << 23);
138	x += 127 << 23;
139	*exp_ptr = x;
140
141	a = ((-1.0f / 3) * a + 2) * a - 2.0f / 3;
142
143	if (b > 2.00001 || b < 1.99999)
144		return (a + log_2) / dcn_bw_log(b, 2);
145	else
146		return (a + log_2);
147}