mirror of
https://github.com/eried/portapack-mayhem.git
synced 2024-12-21 21:45:04 -05:00
033c4e9a5b
* Updated style * Updated files * fixed new line * Updated spacing * File fix WIP * Updated to clang 13 * updated comment style * Removed old comment code
88 lines
2.6 KiB
C++
88 lines
2.6 KiB
C++
/*
|
|
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
|
|
*
|
|
* This file is part of PortaPack.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, Inc., 51 Franklin Street,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#include "lfsr_random.hpp"
|
|
|
|
static void lfsr_iterate_internal(lfsr_word_t& v) {
|
|
/*
|
|
Generated with lfsr-generator:
|
|
http://lfsr-generator.sourceforge.net
|
|
=============================================
|
|
config : fibonacci
|
|
length : 31
|
|
taps : (31, 18)
|
|
shift-amounts : (12, 12, 8)
|
|
shift-direction : left
|
|
*/
|
|
enum {
|
|
length = 31,
|
|
tap_0 = 31,
|
|
tap_1 = 18,
|
|
shift_amount_0 = 12,
|
|
shift_amount_1 = 12,
|
|
shift_amount_2 = 8
|
|
};
|
|
|
|
const lfsr_word_t zero = 0;
|
|
v = ((
|
|
v << shift_amount_0) |
|
|
((
|
|
(v >> (tap_0 - shift_amount_0)) ^
|
|
(v >> (tap_1 - shift_amount_0))) &
|
|
(~(~zero << shift_amount_0))));
|
|
v = ((
|
|
v << shift_amount_1) |
|
|
((
|
|
(v >> (tap_0 - shift_amount_1)) ^
|
|
(v >> (tap_1 - shift_amount_1))) &
|
|
(~(~zero << shift_amount_1))));
|
|
v = ((
|
|
v << shift_amount_2) |
|
|
((
|
|
(v >> (tap_0 - shift_amount_2)) ^
|
|
(v >> (tap_1 - shift_amount_2))) &
|
|
(~(~zero << shift_amount_2))));
|
|
}
|
|
|
|
lfsr_word_t lfsr_iterate(lfsr_word_t v) {
|
|
lfsr_iterate_internal(v);
|
|
return v;
|
|
}
|
|
|
|
void lfsr_fill(lfsr_word_t& v, lfsr_word_t* buffer, size_t word_count) {
|
|
while (word_count != 0) {
|
|
lfsr_iterate_internal(v);
|
|
*(buffer++) = v;
|
|
word_count--;
|
|
}
|
|
}
|
|
|
|
bool lfsr_compare(lfsr_word_t& v, const lfsr_word_t* buffer, size_t word_count) {
|
|
while (word_count != 0) {
|
|
lfsr_iterate_internal(v);
|
|
if (*(buffer++) != v) {
|
|
return false;
|
|
}
|
|
word_count--;
|
|
}
|
|
return true;
|
|
}
|