dcn_calc_math.c

  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}