CORDIC_Abs_APFX/sources/CCordicAbs/CCordicAbs.hpp
2022-09-21 15:53:01 +02:00

184 lines
6.1 KiB
C++

/*
*
* Copyright 2022 Camille "DrasLorus" Monière.
*
* This file is part of CORDIC_Abs_APFX.
*
* This program is free software: you can redistribute it and/or modify it under the terms of the GNU
* Lesser General Public License as published by the Free Software Foundation, either version 3 of
* the License, 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with this program.
* If not, see <https://www.gnu.org/licenses/>.
*
*/
#ifndef C_CORDIC_ABS_HPP
#define C_CORDIC_ABS_HPP
#include <climits>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#if !defined(__SYNTHESIS__) && defined(SOFTWARE)
#include <cmath>
#include <complex>
#endif
#include <ap_fixed.h>
#include <ap_int.h>
#include "hls_abs/hls_abs.hpp"
#define cst_abs(x) (x > 0 ? x : -x)
#if __cplusplus < 201402L && XILINX_MAJOR <= 2019
#ifndef kn_values
const double kn_values_define[27] = {
0.707106781186547, 0.632455532033676, 0.613571991077896, 0.608833912517752,
0.607648256256168, 0.607351770141296, 0.607277644093526, 0.607259112298893,
0.607254479332562, 0.607253321089875, 0.607253031529134, 0.607252959138945,
0.607252941041397, 0.607252936517010, 0.607252935385914, 0.607252935103139,
0.607252935032446, 0.607252935014772, 0.607252935010354, 0.607252935009249,
0.607252935008973, 0.607252935008904, 0.607252935008887, 0.607252935008883,
0.607252935008882, 0.607252935008881};
#define kn_values kn_values_define
#define kn_i unsigned(kn_values[Tnb_stages - 1] * double(1U << 4))
#endif
#define OWN_CONSTEXPR
#else
#define OWN_CONSTEXPR constexpr
#endif
template <unsigned TIn_W, unsigned TIn_I, unsigned Tnb_stages>
class CCordicAbs {
public:
#if __cplusplus >= 201402L || XILINX_MAJOR > 2019
static constexpr double kn_values[27] = {
0.707106781186547, 0.632455532033676, 0.613571991077896, 0.608833912517752,
0.607648256256168, 0.607351770141296, 0.607277644093526, 0.607259112298893,
0.607254479332562, 0.607253321089875, 0.607253031529134, 0.607252959138945,
0.607252941041397, 0.607252936517010, 0.607252935385914, 0.607252935103139,
0.607252935032446, 0.607252935014772, 0.607252935010354, 0.607252935009249,
0.607252935008973, 0.607252935008904, 0.607252935008887, 0.607252935008883,
0.607252935008882, 0.607252935008881};
static constexpr unsigned kn_i = unsigned(kn_values[Tnb_stages - 1] * double(1U << 4)); // 4 bits are enough
#endif
static constexpr unsigned In_W = TIn_W;
static constexpr unsigned In_I = TIn_I;
static constexpr unsigned Out_W = In_W + 4;
static constexpr unsigned Out_I = In_I + 4;
static constexpr unsigned nb_stages = Tnb_stages;
static constexpr unsigned in_scale_factor = unsigned(1U << (In_W - In_I));
static constexpr unsigned out_scale_factor = unsigned(1U << (Out_W - Out_I));
static constexpr uint64_t scale_cordic(uint64_t in) {
return in * kn_i / 16U;
}
static constexpr double scale_cordic(double in) {
return in * kn_values[nb_stages - 1];
}
static constexpr ap_uint<Out_W> scale_cordic(ap_uint<Out_W> in) {
return ap_uint<Out_W>(ap_uint<Out_W + 4>(in * ap_uint<4>(kn_i)) >> 4U);
}
static OWN_CONSTEXPR ap_uint<Out_W> process(ap_int<In_W> re_in, ap_int<In_W> im_in) {
ap_int<Out_W> A[nb_stages + 1];
ap_int<Out_W> B[nb_stages + 1];
A[0] = hls_abs<false>::abs(re_in);
B[0] = hls_abs<false>::abs(im_in);
for (uint16_t u = 0; u < nb_stages; u++) {
const bool sign_B = B[u] > 0;
const ap_int<Out_W> step_A = B[u] >> u;
const ap_int<Out_W> step_B = A[u] >> u;
const ap_int<Out_W> tmp_B = sign_B
? ap_int<Out_W>(B[u] - step_B)
: ap_int<Out_W>(B[u] + step_B);
const ap_int<Out_W> tmp_A = sign_B
? ap_int<Out_W>(A[u] + step_A)
: ap_int<Out_W>(A[u] - step_A);
A[u + 1] = tmp_A;
B[u + 1] = tmp_B;
}
return ap_uint<Out_W>(A[nb_stages]);
}
#if !defined(__SYNTHESIS__) && defined(SOFTWARE) && __cplusplus >= 201402L
static constexpr uint64_t process(int64_t re_in, int64_t im_in) {
const int64_t re_x = re_in;
const int64_t im_x = im_in;
int64_t A = cst_abs(re_x);
int64_t B = cst_abs(im_x);
for (uint16_t u = 1; u < nb_stages + 1; u++) {
const bool sign_B = B > 0;
const int64_t step_A = +B / int64_t(1LU << (u - 1));
const int64_t step_B = -A / int64_t(1LU << (u - 1));
B = sign_B ? B + step_B : B - step_B;
A = sign_B ? A + step_A : A - step_A;
}
return uint64_t(A);
}
static constexpr uint64_t process(const std::complex<int64_t> & x_in) {
const int64_t re_x = x_in.real();
const int64_t im_x = x_in.imag();
int64_t A = cst_abs(re_x);
int64_t B = cst_abs(im_x);
for (uint16_t u = 1; u < nb_stages + 1; u++) {
const bool sign_B = B > 0;
const int64_t step_A = +B / int64_t(1LLU << (u - 1));
const int64_t step_B = -A / int64_t(1LLU << (u - 1));
B = sign_B ? B + step_B : B - step_B;
A = sign_B ? A + step_A : A - step_A;
}
return uint64_t(A);
}
static constexpr double process(std::complex<double> x_in) {
const std::complex<int64_t> fx_x_in(int64_t(x_in.real() * double(in_scale_factor)),
int64_t(x_in.imag() * double(in_scale_factor)));
const uint64_t fx_out = process(fx_x_in);
return scale_cordic(double(fx_out)) / double(out_scale_factor);
}
#endif
constexpr CCordicAbs() = default;
~CCordicAbs() = default;
};
#undef cst_abs
#endif