48 lines
1.7 KiB
C++
48 lines
1.7 KiB
C++
/*
|
|
* Copyright (C) 2014 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.
|
|
*/
|
|
|
|
#ifndef __UTILITY_M4_H__
|
|
#define __UTILITY_M4_H__
|
|
|
|
#if defined(LPC43XX_M4)
|
|
|
|
#include <hal.h>
|
|
|
|
static inline complex32_t multiply_conjugate_s16_s32(const complex16_t::rep_type a, const complex16_t::rep_type b) {
|
|
// conjugate: conj(a + bj) = a - bj
|
|
// multiply: (a + bj) * (c + dj) = (ac - bd) + (bc + ad)j
|
|
// conjugate-multiply: (ac + bd) + (bc - ad)j
|
|
//return { a.real() * b.real() + a.imag() * b.imag(), a.imag() * b.real() - a.real() * b.imag() };
|
|
// NOTE: Did not use combination of SMUAD and SMUSDX because of non-saturating arithmetic.
|
|
// const int32_t r = __SMUAD(a, b);
|
|
// const int32_t i = __SMUSDX(b, a);
|
|
const int32_t rr = __SMULBB(a, b);
|
|
const int32_t ii = __SMULTT(a, b);
|
|
const int32_t r = __QADD(rr, ii);
|
|
const int32_t ir = __SMULTB(a, b);
|
|
const int32_t ri = __SMULBT(a, b);
|
|
const int32_t i = __QSUB(ir, ri);
|
|
return { r, i };
|
|
}
|
|
#endif /* defined(LPC43XX_M4) */
|
|
|
|
#endif/*__UTILITY_M4_H__*/
|