CORDIC_Rotate_APFX/sources/CCordicRotateRom/CCordicRotateRom.hpp.in
anonymous 6afa99d7a1
GNU 4.6 (consequently Xilinx 2019.1) is finally supported
- if GNU version is less than 6.2:
    * Catch2 is disabled, a custom unit test is used instead,
    * Constexpr keyword is largely removed and less used (performance
      loss),
    * Only ML Cordic/Roms are compiled and tested.
- Perfect compilation on g++ v4.6.4, should work on Vivado HLS (g++
  v4.6.3).
2022-05-13 15:53:14 +02:00

166 lines
6.4 KiB
C++

/*
*
* Copyright 2022 Camille "DrasLorus" Monière.
*
* This file is part of CORDIC_Rotate_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_ROTATE_ROM_@CORDIC_W@_@CORDIC_STAGES@_@CORDIC_Q@_@CORDIC_DIVIDER@
#define C_CORDIC_ROTATE_ROM_@CORDIC_W@_@CORDIC_STAGES@_@CORDIC_Q@_@CORDIC_DIVIDER@
#include <climits>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <complex>
#include <ap_fixed.h>
#include <ap_int.h>
#include "CCordicRotateRomTemplate.hpp"
#include "CordicRoms/cordic_rom_@ROM_TYPE@_@CORDIC_W@_@CORDIC_STAGES@_@CORDIC_Q@_@CORDIC_DIVIDER@.hpp"
#include "RomRotateCommon/definitions.hpp"
namespace rcr = rom_cordic_rotate;
#ifndef KN_STATIC_TABLE_DEFINED
#define KN_STATIC_TABLE_DEFINED 1
// ``` GNU Octave
// kn_values(X) = prod(1 ./ abs(1 + 1j * 2.^ (-(0:X))))
// ```
static constexpr double kn_values[7] = {
0.70710678118655, 0.632455532033680, 0.613571991077900,
0.608833912517750, 0.607648256256170, 0.607351770141300, 0.607277644093530};
#endif // KN_STATIC_TABLE_DEFINED
template <unsigned TIn_I>
class CCordicRotateRom<TIn_I, @ROM_TYPE@, @CORDIC_W@, @CORDIC_STAGES@, @CORDIC_Q@, @CORDIC_DIVIDER@> {
static_assert(@CORDIC_W@ > 0, "Inputs can't be on zero bits.");
static_assert(@CORDIC_STAGES@ < 8, "7 stages of CORDIC is the maximum supported.");
static_assert(@CORDIC_STAGES@ > 1, "2 stages of CORDIC is the minimum.");
static_assert(rcr::is_pow_2<@CORDIC_DIVIDER@>(), "divider must be a power of 2.");
public:
static constexpr unsigned In_W = @CORDIC_W@;
static constexpr unsigned In_I = TIn_I;
static constexpr unsigned Out_W = In_W + 2;
static constexpr unsigned Out_I = In_I + 2;
static constexpr unsigned nb_stages = @CORDIC_STAGES@;
static constexpr unsigned q = @CORDIC_Q@;
static constexpr uint64_t kn_i = uint64_t(kn_values[nb_stages - 1] * double(1U << 4)); // 4 bits are enough
static constexpr uint64_t in_scale_factor = uint64_t(1U << (In_W - In_I));
static constexpr uint64_t out_scale_factor = uint64_t(1U << (Out_W - Out_I));
static constexpr double rotation = rcr::pi / @CORDIC_DIVIDER@;
static constexpr unsigned addr_length = cordic_roms::@ROM_TYPE@_@CORDIC_W@_@CORDIC_STAGES@_@CORDIC_Q@_@CORDIC_DIVIDER@_size;
static constexpr int64_t scale_cordic(int64_t in) {
return in * kn_i / 16U;
}
#if !defined(__SYNTHESIS__) && defined(SOFTWARE) && __cplusplus >= 201402L
static constexpr std::complex<int64_t> cordic(std::complex<int64_t> x_in,
uint8_t counter) {
int64_t A = x_in.real();
int64_t B = x_in.imag();
const uint8_t R = cordic_roms::@ROM_TYPE@_@CORDIC_W@_@CORDIC_STAGES@_@CORDIC_Q@_@CORDIC_DIVIDER@[counter];
uint8_t mask = 0x01;
if ((R & mask) == mask) {
A = -A;
B = -B;
}
for (uint8_t u = 1; u < nb_stages + 1; u++) {
mask = mask << 1;
const int64_t Ri = (R & mask) == mask ? 1 : -1;
const int64_t I = A + Ri * (B / int64_t(1U << (u - 1)));
B = B - Ri * (A / int64_t(1U << (u - 1)));
A = I;
}
return {(A), (B)};
}
static constexpr double scale_cordic(double in) {
return in * kn_values[nb_stages - 1];
}
static constexpr std::complex<double> cordic(std::complex<double> x_in,
uint8_t counter) {
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 std::complex<int64_t> fx_out = cordic(fx_x_in, counter);
return {scale_cordic(double(fx_out.real())) / double(out_scale_factor), scale_cordic(double(fx_out.imag())) / double(out_scale_factor)};
}
#endif
static ap_int<Out_W> scale_cordic(const ap_int<Out_W> & in) {
const ap_int<Out_W + 4> tmp = in * ap_uint<4>(kn_i);
return ap_int<Out_W>(tmp >> 4);
}
static void cordic(const ap_int<In_W> & re_in, const ap_int<In_W> & im_in,
const ap_uint<8> & counter,
ap_int<Out_W> & re_out, ap_int<Out_W> & im_out) {
const ap_uint<nb_stages + 1> R = *(cordic_roms::@ROM_TYPE@_@CORDIC_W@_@CORDIC_STAGES@_@CORDIC_Q@_@CORDIC_DIVIDER@ + counter);
ap_int<Out_W> A = bool(R[0]) ? ap_int<In_W>(-re_in) : re_in;
ap_int<Out_W> B = bool(R[0]) ? ap_int<In_W>(-im_in) : im_in;
for (uint8_t u = 1; u < nb_stages + 1; u++) { // nb_stages stages
const bool Ri = bool(R[u]);
// Results in (X / 2^(u - 1)), meaning only the
// Out_W - u LSBs are meaninfull in shifted_X
// Can't use range access since 11111111 (-1) would become 00001111 (15).
// Would be possible if the loop is manually unrolled, to predict bitsize,
// thus directly put 1111 into 4 bits (so still -1).
const ap_int<Out_W> shifted_A = A >> (u - 1); // A(Out_W - 1, u - 1);
const ap_int<Out_W> shifted_B = B >> (u - 1); // B(Out_W - 1, u - 1);
const ap_int<Out_W> arc_step_A
= Ri
? ap_int<Out_W>(-shifted_A)
: shifted_A;
const ap_int<Out_W> arc_step_B
= Ri
? shifted_B
: ap_int<Out_W>(-shifted_B);
const ap_int<Out_W + 1> I = A + arc_step_B;
B = B + arc_step_A;
A = I;
}
re_out = A;
im_out = B;
}
constexpr CCordicRotateRom() = default;
};
#endif // C_CORDIC_ROTATE_ROM_W_STAGES_Q_DIVIDER