drivers/gpu/drm/amd/display/dc/calcs/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 "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
  39 float 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
  48 float 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
  57 unsigned int dcn_bw_max(const unsigned int arg1, const unsigned int arg2)
  58 {
  59         return arg1 > arg2 ? arg1 : arg2;
  60 }
  61 float 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
  70 float dcn_bw_floor2(const float arg, const float significance)
  71 {
  72         if (significance == 0)
  73                 return 0;
  74         return ((int) (arg / significance)) * significance;
  75 }
  76 float dcn_bw_floor(const float arg)
  77 {
  78         return ((int) (arg));
  79 }
  80
  81 float 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
  88 float 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
  96 float 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
 101 float 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
 106 float 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
 123 double dcn_bw_fabs(double a)
 124 {
 125         if (a > 0)
 126                 return (a);
 127         else
 128                 return (-a);
 129 }
 130
 131
 132 float 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 }