cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

dcn_calc_math.c (3723B)

      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}