/github/workspace/src/TransformFunctions/kernels/plp_rfft_f32s_xpulpv2.c
Functions
| Name | |
|---|---|
| int | bit_rev_radix2(int index, int log2FFTLen) |
| int | bit_rev_radix4(int index, int log2FFTLen) |
| int | bit_rev_radix8(int index, int log2FFTLen) |
| int | bit_rev_2_4(int value, int log2FFTLen) |
| Complex_type_f32 | complex_mul(Complex_type_f32 A, Complex_type_f32 B) |
| Complex_type_f32 | complex_mul_real(float32_t A, Complex_type_f32 B) |
| void | plp_rfft_f32s_xpulpv2(const plp_fft_instance_f32 * S, const float32_t restrict pSrc, float32_t restrict pDst) Floating-point FFT on real input data for XPULPV2 extension. |
| void | plp_radix2_rfft_f32s_xpulpv2(const plp_fft_instance_f32 * S, const float32_t restrict pSrc, float32_t restrict pDst) |
| void | process_butterfly_real_radix2(const float32_t *restrict input, Complex_type_f32 * output, int twiddle_index, int distance, Complex_type_f32 * twiddle_ptr) |
| void | process_butterfly_radix2(Complex_type_f32 * input, Complex_type_f32 * output, int twiddle_index, int index, int distance, Complex_type_f32 * twiddle_ptr) |
| void | process_butterfly_last_radix2(Complex_type_f32 * input, Complex_type_f32 * output, int outindex) |
| void | plp_radix4_rfft_f32s_xpulpv2(const plp_fft_instance_f32 * S, const float32_t restrict pSrc, float32_t restrict pDst) |
| void | process_butterfly_real_radix4(const float32_t *restrict input, Complex_type_f32 * output, int twiddle_index, int distance, Complex_type_f32 * twiddle_ptr) |
| void | process_butterfly_radix4(Complex_type_f32 * input, Complex_type_f32 * output, int twiddle_index, int index, int distance, Complex_type_f32 * twiddle_ptr) |
| void | process_butterfly_last_radix4(Complex_type_f32 * input, Complex_type_f32 * output, int outindex) |
| void | plp_radix8_rfft_f32s_xpulpv2(const plp_fft_instance_f32 * S, const float32_t restrict pSrc, float32_t restrict pDst) |
| void | process_butterfly_real_radix8(const float32_t *restrict input, Complex_type_f32 * output, int twiddle_index, int distance, Complex_type_f32 * twiddle_ptr) |
| void | process_butterfly_radix8(Complex_type_f32 * input, Complex_type_f32 * output, int twiddle_index, int index, int distance, Complex_type_f32 * twiddle_ptr) |
| void | process_butterfly_last_radix8(Complex_type_f32 * input, Complex_type_f32 * output, int outindex) |
| void | plp_radix_2by4_rfft_f32s_xpulpv2(const plp_fft_instance_f32 * S, const float32_t *restrict pSrc, float32_t * pDst) |
| void | fft_radix4_mixed(float32_t restrict pSrc, float32_t restrict pDst, uint32_t FFTLength, const float32_t * pTwiddleFactors) |
Attributes
| Name | |
|---|---|
| HAL_CL_L1 float32_t | ROT_CONST |
Functions Documentation
function bit_rev_radix2
int bit_rev_radix2(
int index,
int log2FFTLen
)
end of realFFTKernels group
function bit_rev_radix4
int bit_rev_radix4(
int index,
int log2FFTLen
)
function bit_rev_radix8
int bit_rev_radix8(
int index,
int log2FFTLen
)
function bit_rev_2_4
int bit_rev_2_4(
int value,
int log2FFTLen
)
function complex_mul
static inline Complex_type_f32 complex_mul(
Complex_type_f32 A,
Complex_type_f32 B
)
function complex_mul_real
static inline Complex_type_f32 complex_mul_real(
float32_t A,
Complex_type_f32 B
)
function plp_rfft_f32s_xpulpv2
void plp_rfft_f32s_xpulpv2(
const plp_fft_instance_f32 * S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst
)
Floating-point FFT on real input data for XPULPV2 extension.
Parameters:
- S points to an instance of the floating-point FFT structure
- pSrc points to the input buffer (real data)
- pDst points to the output buffer (complex data)
Return: none
function plp_radix2_rfft_f32s_xpulpv2
static void plp_radix2_rfft_f32s_xpulpv2(
const plp_fft_instance_f32 * S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst
)
function process_butterfly_real_radix2
static inline void process_butterfly_real_radix2(
const float32_t *__restrict__ input,
Complex_type_f32 * output,
int twiddle_index,
int distance,
Complex_type_f32 * twiddle_ptr
)
function process_butterfly_radix2
static inline void process_butterfly_radix2(
Complex_type_f32 * input,
Complex_type_f32 * output,
int twiddle_index,
int index,
int distance,
Complex_type_f32 * twiddle_ptr
)
function process_butterfly_last_radix2
static inline void process_butterfly_last_radix2(
Complex_type_f32 * input,
Complex_type_f32 * output,
int outindex
)
function plp_radix4_rfft_f32s_xpulpv2
static void plp_radix4_rfft_f32s_xpulpv2(
const plp_fft_instance_f32 * S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst
)
function process_butterfly_real_radix4
static inline void process_butterfly_real_radix4(
const float32_t *__restrict__ input,
Complex_type_f32 * output,
int twiddle_index,
int distance,
Complex_type_f32 * twiddle_ptr
)
function process_butterfly_radix4
static inline void process_butterfly_radix4(
Complex_type_f32 * input,
Complex_type_f32 * output,
int twiddle_index,
int index,
int distance,
Complex_type_f32 * twiddle_ptr
)
function process_butterfly_last_radix4
static inline void process_butterfly_last_radix4(
Complex_type_f32 * input,
Complex_type_f32 * output,
int outindex
)
function plp_radix8_rfft_f32s_xpulpv2
static void plp_radix8_rfft_f32s_xpulpv2(
const plp_fft_instance_f32 * S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst
)
function process_butterfly_real_radix8
static inline void process_butterfly_real_radix8(
const float32_t *__restrict__ input,
Complex_type_f32 * output,
int twiddle_index,
int distance,
Complex_type_f32 * twiddle_ptr
)
function process_butterfly_radix8
static inline void process_butterfly_radix8(
Complex_type_f32 * input,
Complex_type_f32 * output,
int twiddle_index,
int index,
int distance,
Complex_type_f32 * twiddle_ptr
)
function process_butterfly_last_radix8
static inline void process_butterfly_last_radix8(
Complex_type_f32 * input,
Complex_type_f32 * output,
int outindex
)
function plp_radix_2by4_rfft_f32s_xpulpv2
static void plp_radix_2by4_rfft_f32s_xpulpv2(
const plp_fft_instance_f32 * S,
const float32_t *__restrict__ pSrc,
float32_t * pDst
)
function fft_radix4_mixed
static void fft_radix4_mixed(
float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst,
uint32_t FFTLength,
const float32_t * pTwiddleFactors
)
Attributes Documentation
variable ROT_CONST
static HAL_CL_L1 float32_t ROT_CONST = 0.707106781f;
Source code
/* =====================================================================
* Project: PULP DSP Library
* Title: plp_rfft_f32s_xpulpv2.c
* Description: Floating-point FFT on real input data for XPULPV2
*
* $Date: 10. Aug 2020
* $Revision: V1
*
* Target Processor: PULP cores with "F" support (wolfe, vega)
* ===================================================================== */
/*
* Copyright (C) 2020 ETH Zurich and University of Bologna. All rights reserved.
*
* Author: Giuseppe Tagliavini, University of Bologna
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "plp_math.h"
static HAL_CL_L1 float32_t ROT_CONST = 0.707106781f;
/* HELPER FUNCTIONS */
int bit_rev_radix2(int index, int log2FFTLen);
int bit_rev_radix4(int index, int log2FFTLen);
int bit_rev_radix8(int index, int log2FFTLen);
int bit_rev_2_4(int value, int log2FFTLen);
static inline Complex_type_f32 complex_mul(Complex_type_f32 A, Complex_type_f32 B) {
Complex_type_f32 result;
result.re = A.re * B.re - A.im * B.im;
result.im = A.re * B.im + A.im * B.re;
return result;
}
static inline Complex_type_f32 complex_mul_real(float32_t A, Complex_type_f32 B) {
Complex_type_f32 result;
result.re = A * B.re;
result.im = A * B.im;
return result;
}
void plp_rfft_f32s_xpulpv2(const plp_fft_instance_f32 *S, const float32_t *__restrict__ pSrc, float32_t *__restrict__ pDst);
/* RADIX-2 */
static void plp_radix2_rfft_f32s_xpulpv2(const plp_fft_instance_f32 *S, const float32_t *__restrict__ pSrc, float32_t *__restrict__ pDst);
static inline void process_butterfly_real_radix2(const float32_t *__restrict__ input, Complex_type_f32 *output, int twiddle_index, int distance, Complex_type_f32 *twiddle_ptr);
static inline void process_butterfly_radix2(Complex_type_f32 *input, Complex_type_f32* output, int twiddle_index, int index, int distance, Complex_type_f32 *twiddle_ptr);
static inline void process_butterfly_last_radix2(Complex_type_f32 *input, Complex_type_f32 *output, int outindex);
/* RADIX-4 */
static void plp_radix4_rfft_f32s_xpulpv2(const plp_fft_instance_f32 *S, const float32_t *__restrict__ pSrc, float32_t *__restrict__ pDst);
static inline void process_butterfly_real_radix4 (const float32_t *__restrict__ input, Complex_type_f32* output, int twiddle_index, int distance, Complex_type_f32* twiddle_ptr);
static inline void process_butterfly_radix4 (Complex_type_f32* input, Complex_type_f32* output, int twiddle_index, int index, int distance, Complex_type_f32* twiddle_ptr);
static inline void process_butterfly_last_radix4 (Complex_type_f32* input, Complex_type_f32* output, int outindex );
/* RADIX-8 */
static void plp_radix8_rfft_f32s_xpulpv2(const plp_fft_instance_f32 *S, const float32_t *__restrict__ pSrc, float32_t *__restrict__ pDst);
static inline void process_butterfly_real_radix8 (const float32_t *__restrict__ input, Complex_type_f32* output, int twiddle_index, int distance, Complex_type_f32* twiddle_ptr);
static inline void process_butterfly_radix8 (Complex_type_f32* input, Complex_type_f32* output, int twiddle_index, int index, int distance, Complex_type_f32* twiddle_ptr);
static inline void process_butterfly_last_radix8 (Complex_type_f32* input, Complex_type_f32* output, int outindex );
/* RADIX-4_2 */
static void plp_radix_2by4_rfft_f32s_xpulpv2(const plp_fft_instance_f32 *S, const float32_t *__restrict__ pSrc, float32_t* pDst);
static void fft_radix4_mixed( float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst,
uint32_t FFTLength,
const float32_t *pTwiddleFactors);
void plp_rfft_f32s_xpulpv2( const plp_fft_instance_f32 *S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst) {
switch( S->FFTLength ) {
case 64:
case 512:
plp_radix8_rfft_f32s_xpulpv2(S, pSrc, pDst);
break;
case 16:
case 256:
case 1024:
plp_radix4_rfft_f32s_xpulpv2(S, pSrc, pDst);
break;
case 32:
case 128:
plp_radix2_rfft_f32s_xpulpv2(S, pSrc, pDst);
break;
case 2048:
plp_radix_2by4_rfft_f32s_xpulpv2(S, pSrc, pDst);
break;
}
}
/* RADIX-2 */
int bit_rev_radix2(int index, int log2FFTLen) {
unsigned int revNum = 0;
unsigned i;
for (i = 0; i < log2FFTLen; i++) {
unsigned int temp = (index & (1 << i));
if (temp != 0)
revNum |= (1 << ((log2FFTLen - 1) - i));
}
return revNum;
}
static inline void process_butterfly_real_radix2( const float32_t *__restrict__ input,
Complex_type_f32 *output,
int twiddle_index,
int distance,
Complex_type_f32 *twiddle_ptr) {
int index = 0;
float32_t d0 = input[index];
float32_t d1 = input[index + distance];
Complex_type_f32 r0, r1;
// Re(c1*c2) = c1.re*c2.re - c1.im*c2.im, since c1 is real = c1.re*c2.re
r0.re = d0 + d1;
// r0.im = 0.0f;
r1.re = d0 - d1;
Complex_type_f32 tw0 = twiddle_ptr[twiddle_index];
output[index] = r0;
output[index + distance] = complex_mul_real(r1.re, tw0);
}
static inline void process_butterfly_radix2( Complex_type_f32 *input,
Complex_type_f32 *output,
int twiddle_index,
int index,
int distance,
Complex_type_f32 *twiddle_ptr) {
Complex_type_f32 r0, r1;
float32_t d0 = input[index].re;
float32_t d1 = input[index + distance].re;
float32_t e0 = input[index].im;
float32_t e1 = input[index + distance].im;
// Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
r0.re = d0 + d1;
r1.re = d0 - d1;
// Im(c1*c2) = c1.re*c2.im + c1.im*c2.re
r0.im = e0 + e1;
r1.im = e0 - e1;
Complex_type_f32 tw0 = twiddle_ptr[twiddle_index];
output[index] = r0;
output[index + distance] = complex_mul(tw0, r1);
}
static inline void process_butterfly_last_radix2 ( Complex_type_f32 *input,
Complex_type_f32 *output,
int outindex) {
int index = 0;
Complex_type_f32 r0, r1;
float32_t d0 = input[index].re;
float32_t d1 = input[index + 1].re;
float32_t e0 = input[index].im;
float32_t e1 = input[index + 1].im;
// Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
r0.re = d0 + d1;
r1.re = d0 - d1;
// Im(c1*c2) = c1.re*c2.im + c1.im*c2.re
r0.im = e0 + e1;
r1.im = e0 - e1;
/* In the Last step, twiddle factors are all 1 */
output[outindex ] = r0;
output[outindex+1] = r1;
}
static void plp_radix2_rfft_f32s_xpulpv2( const plp_fft_instance_f32 *S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst) {
int k, j, stage, step, d, index;
Complex_type_f32 temp;
int dist = S->FFTLength >> 1;
int nbutterfly = S->FFTLength >> 1;
int butt = 2; // number of butterflies in the same group
Complex_type_f32 *_in_ptr;
Complex_type_f32 *_out_ptr;
Complex_type_f32 *_tw_ptr;
// FIRST STAGE
stage = 1;
_out_ptr = (Complex_type_f32 *)pDst;
_tw_ptr = (Complex_type_f32 *)S->pTwiddleFactors;
for (j = 0; j < nbutterfly; j++) {
process_butterfly_real_radix2(pSrc, _out_ptr, j, dist, _tw_ptr);
pSrc++;
_out_ptr++;
} // j
stage = stage + 1;
dist = dist >> 1;
// STAGES 2 -> n-1
while (dist > 1) {
step = dist << 1;
for (j = 0; j < butt; j++) {
_in_ptr = (Complex_type_f32 *)pDst;
for (d = 0; d < dist; d++) {
process_butterfly_radix2(_in_ptr, _in_ptr, d * butt, j * step, dist, _tw_ptr);
_in_ptr++;
} // d
} // j
stage = stage + 1;
dist = dist >> 1;
butt = butt << 1;
}
// LAST STAGE
_in_ptr = (Complex_type_f32 *)pDst;
index = 0;
for (j = 0; j < (S->FFTLength >> 1); j++) {
process_butterfly_last_radix2(_in_ptr, (Complex_type_f32 *)pDst, index);
_in_ptr += 2;
index += 2;
} // j
// ORDER VALUES
if (S->bitReverseFlag) {
int index1, index2, index3, index4;
_out_ptr = (Complex_type_f32 *)pDst;
for (j = 0; j < S->FFTLength; j += 4) {
if (S->pBitReverseLUT) {
unsigned int index12 = *((unsigned int *)(&S->pBitReverseLUT[j]));
unsigned int index34 = *((unsigned int *)(&S->pBitReverseLUT[j + 2]));
index1 = index12 & 0x0000FFFF;
index2 = index12 >> 16;
index3 = index34 & 0x0000FFFF;
index4 = index34 >> 16;
} else {
int log2FFTLen = log2(S->FFTLength);
index1 = bit_rev_radix2(j, log2FFTLen);
index2 = bit_rev_radix2(j + 1, log2FFTLen);
index3 = bit_rev_radix2(j + 2, log2FFTLen);
index4 = bit_rev_radix2(j + 3, log2FFTLen);
}
if (index1 > j) {
temp = _out_ptr[j];
_out_ptr[j] = _out_ptr[index1];
_out_ptr[index1] = temp;
}
if (index2 > j + 1) {
temp = _out_ptr[j + 1];
_out_ptr[j + 1] = _out_ptr[index2];
_out_ptr[index2] = temp;
}
if (index3 > j + 2) {
temp = _out_ptr[j + 2];
_out_ptr[j + 2] = _out_ptr[index3];
_out_ptr[index3] = temp;
}
if (index4 > j + 3) {
temp = _out_ptr[j + 3];
_out_ptr[j + 3] = _out_ptr[index4];
_out_ptr[index4] = temp;
}
}
}
}
/* RADIX-4 */
int bit_rev_radix4(int index, int log2FFTLen) //digit reverse 2 bit blocks
{
int i;
unsigned int revNum = 0;
for (i = 0; i < log2FFTLen/2; i++)
{
revNum <<= 2;
revNum |= (index & 0x3);
index >>= 2;
}
return revNum;
}
static inline void process_butterfly_real_radix4 ( const float32_t *__restrict__ input,
Complex_type_f32* output,
int twiddle_index,
int distance,
Complex_type_f32* twiddle_ptr) {
Complex_type_f32 r0, r1, r2, r3;
float32_t d0, d1, d2, d3;
Complex_type_f32 tw1, tw2, tw3;
d0 = input[0];
d1 = input[distance];
d2 = input[2*distance];
d3 = input[3*distance];
// Basic buttefly rotation
/*
r0 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i
r1 1.0000 + 0.0000i 0.7071 - 0.7071i 0.0000 - 1.0000i -0.7071 - 0.7071i -1.0000 - 0.0000i -0.7071 + 0.7071i 0.0000 + 1.0000i 0.7071 + 0.7071i
r2 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i
r3 1.0000 + 0.0000i -0.7071 - 0.7071i -0.0000 + 1.0000i 0.7071 - 0.7071i -1.0000 - 0.0000i 0.7071 + 0.7071i 0.0000 - 1.0000i -0.7071 + 0.7071i
*/
//Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
r0.re = d0 + d1 + d2 + d3;
r1.re = d0 - d2;
r2.re = d0 - d1 + d2 - d3;
r3.re = r1.re;
r0.im = 0.0f;
r1.im = -d1 + d3;
r2.im = 0.0f;
r3.im = d1 - d3;
//Im(c1*c2) = c1.re*c2.im + c1.im*c2.re
tw1 = twiddle_ptr[twiddle_index];
tw2 = twiddle_ptr[twiddle_index*2];
tw3 = twiddle_ptr[twiddle_index*3];
output[0] = r0;
output[distance] = complex_mul(r1, tw1);
output[2*distance] = complex_mul_real(r2.re, tw2);
output[3*distance] = complex_mul(r3, tw3);
}
static inline void process_butterfly_radix4 ( Complex_type_f32* input,
Complex_type_f32* output,
int twiddle_index,
int index,
int distance,
Complex_type_f32* twiddle_ptr) {
Complex_type_f32 r0, r1, r2, r3;
float32_t d0, d1, d2, d3;
float32_t e0, e1, e2, e3;
Complex_type_f32 tw1, tw2, tw3;
d0 = input[index].re;
d1 = input[index+distance].re;
d2 = input[index+2*distance].re;
d3 = input[index+3*distance].re;
e0 = input[index].im;
e1 = input[index+distance].im;
e2 = input[index+2*distance].im;
e3 = input[index+3*distance].im;
// Basic buttefly rotation
/*
r0 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i
r1 1.0000 + 0.0000i 0.7071 - 0.7071i 0.0000 - 1.0000i -0.7071 - 0.7071i -1.0000 - 0.0000i -0.7071 + 0.7071i 0.0000 + 1.0000i 0.7071 + 0.7071i
r2 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i
r3 1.0000 + 0.0000i -0.7071 - 0.7071i -0.0000 + 1.0000i 0.7071 - 0.7071i -1.0000 - 0.0000i 0.7071 + 0.7071i 0.0000 - 1.0000i -0.7071 + 0.7071i
*/
//Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
r0.re = d0 + d1 + d2 + d3;
r1.re = d0 - d2 - ( e3 - e1 );
r2.re = d0 - d1 + d2 - d3;
r3.re = d0 - d2 - ( e1 - e3 );
//Im(c1*c2) = c1.re*c2.im + c1.im*c2.re
r0.im = e0 + e1 + e2 + e3;
output[index] = r0;
r1.im = -d1 + d3 + e0 - e2;
r2.im = e0 - e1 + e2 - e3;
r3.im = d1 - d3 + e0 - e2;
tw1 = twiddle_ptr[twiddle_index];
tw2 = twiddle_ptr[twiddle_index*2];
tw3 = twiddle_ptr[twiddle_index*3];
output[index+distance] = complex_mul(tw1, r1);
output[index+2*distance] = complex_mul(tw2, r2);
output[index+3*distance] = complex_mul(tw3, r3);
}
static inline void process_butterfly_last_radix4 ( Complex_type_f32* input,
Complex_type_f32* output,
int outindex ) {
int index = 0;
Complex_type_f32 r0, r1, r2, r3;
float32_t d0 = input[index].re;
float32_t d1 = input[index+1].re;
float32_t d2 = input[index+2].re;
float32_t d3 = input[index+3].re;
float32_t e0 = input[index].im;
float32_t e1 = input[index+1].im;
float32_t e2 = input[index+2].im;
float32_t e3 = input[index+3].im;
/* twiddles are all 1s*/
// Basic buttefly rotation
/*
r0 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i
r1 1.0000 + 0.0000i 0.7071 - 0.7071i 0.0000 - 1.0000i -0.7071 - 0.7071i -1.0000 - 0.0000i -0.7071 + 0.7071i 0.0000 + 1.0000i 0.7071 + 0.7071i
r2 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i
r3 1.0000 + 0.0000i -0.7071 - 0.7071i -0.0000 + 1.0000i 0.7071 - 0.7071i -1.0000 - 0.0000i 0.7071 + 0.7071i 0.0000 - 1.0000i -0.7071 + 0.7071i
*/
// Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
r0.re = d0 + d1 + d2 + d3;
r1.re = d0 - d2 - ( e3 - e1 );
r2.re = d0 - d1 + d2 - d3;
r3.re = d0 - d2 - ( e1 - e3 );
// Im(c1*c2) = c1.re*c2.im + c1.im*c2.re
r0.im = e0 + e1 + e2 + e3;
r1.im = -d1 + d3 + e0 - e2;
r2.im = e0 - e1 + e2 - e3;
r3.im = d1 - d3 + e0 - e2;
output[outindex ] = r0;
output[outindex+1] = r1;
output[outindex+2] = r2;
output[outindex+3] = r3;
}
static void plp_radix4_rfft_f32s_xpulpv2( const plp_fft_instance_f32 *S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst) {
int k, j, stage, step, d, index;
Complex_type_f32 temp;
int dist = S->FFTLength >> 2;
int nbutterfly = S->FFTLength >> 2;
int butt = 4; // number of butterflies in the same group
Complex_type_f32 *_in_ptr;
Complex_type_f32 *_out_ptr;
Complex_type_f32 *_tw_ptr;
// FIRST STAGE
stage = 1;
_out_ptr = (Complex_type_f32 *)pDst;
_tw_ptr = (Complex_type_f32 *)S->pTwiddleFactors;
for (j = 0; j < nbutterfly; j++) {
process_butterfly_real_radix4(pSrc, _out_ptr, j, dist, _tw_ptr);
pSrc++;
_out_ptr++;
} // j
stage = stage + 1;
dist = dist >> 2;
// STAGES 2 -> n-1
while (dist > 1) {
step = dist << 2;
for (j = 0; j < butt; j++) {
_in_ptr = (Complex_type_f32 *)pDst;
for (d = 0; d < dist; d++) {
process_butterfly_radix4(_in_ptr, _in_ptr, d * butt, j * step, dist, _tw_ptr);
_in_ptr++;
} // d
} // j
stage = stage + 1;
dist = dist >> 2;
butt = butt << 2;
}
// LAST STAGE
_in_ptr = (Complex_type_f32 *)pDst;
index = 0;
for (j = 0; j < (S->FFTLength >> 2); j++) {
process_butterfly_last_radix4(_in_ptr, (Complex_type_f32 *)pDst, index);
_in_ptr += 4;
index += 4;
} // j
// ORDER VALUES
if (S->bitReverseFlag) {
int index1, index2, index3, index4;
_out_ptr = (Complex_type_f32 *)pDst;
for (j = 0; j < S->FFTLength; j += 4) {
if (S->pBitReverseLUT) {
unsigned int index12 = *((unsigned int *)(&S->pBitReverseLUT[j]));
unsigned int index34 = *((unsigned int *)(&S->pBitReverseLUT[j + 2]));
index1 = index12 & 0x0000FFFF;
index2 = index12 >> 16;
index3 = index34 & 0x0000FFFF;
index4 = index34 >> 16;
} else {
int log2FFTLen = log2(S->FFTLength);
index1 = bit_rev_radix4(j, log2FFTLen);
index2 = bit_rev_radix4(j + 1, log2FFTLen);
index3 = bit_rev_radix4(j + 2, log2FFTLen);
index4 = bit_rev_radix4(j + 3, log2FFTLen);
}
if (index1 > j) {
temp = _out_ptr[j];
_out_ptr[j] = _out_ptr[index1];
_out_ptr[index1] = temp;
}
if (index2 > j + 1) {
temp = _out_ptr[j + 1];
_out_ptr[j + 1] = _out_ptr[index2];
_out_ptr[index2] = temp;
}
if (index3 > j + 2) {
temp = _out_ptr[j + 2];
_out_ptr[j + 2] = _out_ptr[index3];
_out_ptr[index3] = temp;
}
if (index4 > j + 3) {
temp = _out_ptr[j + 3];
_out_ptr[j + 3] = _out_ptr[index4];
_out_ptr[index4] = temp;
}
}
}
}
/* RADIX-8 */
int bit_rev_radix8(int index, int log2FFTLen) //digit reverse 2 bit blocks
{
int i;
unsigned int revNum = 0;
for (i = 0; i < log2FFTLen/3; i++)
{
revNum <<= 3;
revNum |= (index & 0x7);
index >>= 3;
}
return revNum;
}
static inline void process_butterfly_real_radix8 ( const float32_t *__restrict__ input,
Complex_type_f32* output,
int twiddle_index,
int distance,
Complex_type_f32* twiddle_ptr) {
float32_t d0, d1, d2, d3, d4, d5, d6, d7;
Complex_type_f32 r0, r1, r2, r3, r4, r5, r6, r7;
Complex_type_f32 tw1, tw2, tw3, tw4, tw5, tw6, tw7;
d0 = input[0];
d1 = input[distance];
d2 = input[2*distance];
d3 = input[3*distance];
d4 = input[4*distance];
d5 = input[5*distance];
d6 = input[6*distance];
d7 = input[7*distance];
// Basic buttefly rotation
/*
r0 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i
r1 1.0000 + 0.0000i 0.7071 - 0.7071i 0.0000 - 1.0000i -0.7071 - 0.7071i -1.0000 - 0.0000i -0.7071 + 0.7071i 0.0000 + 1.0000i 0.7071 + 0.7071i
r2 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i
r3 1.0000 + 0.0000i -0.7071 - 0.7071i -0.0000 + 1.0000i 0.7071 - 0.7071i -1.0000 - 0.0000i 0.7071 + 0.7071i 0.0000 - 1.0000i -0.7071 + 0.7071i
r4 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i
r5 1.0000 + 0.0000i -0.7071 + 0.7071i 0.0000 - 1.0000i 0.7071 + 0.7071i -1.0000 - 0.0000i 0.7071 - 0.7071i -0.0000 + 1.0000i -0.7071 - 0.7071i
r6 1.0000 + 0.0000i 0.0000 + 1.0000i -1.0000 - 0.0000i 0.0000 - 1.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i -1.0000 - 0.0000i 0.0000 - 1.0000i
r7 1.0000 + 0.0000i 0.7071 + 0.7071i -0.0000 + 1.0000i -0.7071 + 0.7071i -1.0000 - 0.0000i -0.7071 - 0.7071i 0.0000 - 1.0000i 0.7071 - 0.7071i
*/
//Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
float32_t d13 = d1 + d3;
float32_t d1_3 = d1 - d3;
float32_t d57 = d5 + d7;
float32_t d_57 = d7 - d5;
float32_t temp1 = ROT_CONST*(d1_3+d_57);
float32_t temp2 = ROT_CONST*(d57-d13);
float32_t d04 = d0 + d4;
float32_t d0_4 = d0 - d4;
float32_t d26 = d2 + d6;
float32_t d_26 = d6 - d2;
float32_t d0246 = d04 + d26;
float32_t d1357 = d13 + d57;
r0.re = d0246 + d1357;
r1.re = d0_4 + temp1;
r7.re = r1.re;
r1.re = r1.re;
r2.re = d04 - d26;
r6.re = r2.re;
r2.re = r2.re;
r3.re = d0_4 - temp1;
r5.re = r3.re;
r3.re = r3.re;
r4.re = d0246 - d1357;
r1.im = d_26 + temp2;
r2.im = d_57 - d1_3;
r3.im = temp2 - d_26;
r5.im = -r3.im;
r6.im = -r2.im;
r7.im = -r1.im;
// TWIDDLES
tw1 = twiddle_ptr[twiddle_index*1];
tw2 = twiddle_ptr[twiddle_index*2];
tw3 = twiddle_ptr[twiddle_index*3];
tw4 = twiddle_ptr[twiddle_index*4];
tw5 = twiddle_ptr[twiddle_index*5];
tw6 = twiddle_ptr[twiddle_index*6];
tw7 = twiddle_ptr[twiddle_index*7];
output[0] = r0;
output[distance] = complex_mul(tw1, r1);
output[2*distance] = complex_mul(tw2, r2);
output[3*distance] = complex_mul(tw3, r3);
output[4*distance] = complex_mul_real(r4.re, tw4);
output[5*distance] = complex_mul(tw5, r5);
output[6*distance] = complex_mul(tw6, r6);
output[7*distance] = complex_mul(tw7, r7);
}
static inline void process_butterfly_radix8 ( Complex_type_f32* input,
Complex_type_f32* output,
int twiddle_index,
int index,
int distance,
Complex_type_f32* twiddle_ptr) {
float32_t d0, d1, d2, d3, d4, d5, d6, d7;
float32_t e0, e1, e2, e3, e4, e5, e6, e7;
Complex_type_f32 r0, r1, r2, r3, r4, r5, r6, r7;
Complex_type_f32 tw1, tw2, tw3, tw4, tw5, tw6, tw7;
d0 = input[index].re;
d1 = input[index+distance].re;
d2 = input[index+2*distance].re;
d3 = input[index+3*distance].re;
d4 = input[index+4*distance].re;
d5 = input[index+5*distance].re;
d6 = input[index+6*distance].re;
d7 = input[index+7*distance].re;
e0 = input[index].im;
e1 = input[index+distance].im;
e2 = input[index+2*distance].im;
e3 = input[index+3*distance].im;
e4 = input[index+4*distance].im;
e5 = input[index+5*distance].im;
e6 = input[index+6*distance].im;
e7 = input[index+7*distance].im;
// Basic buttefly rotation
/*
r0 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i
r1 1.0000 + 0.0000i 0.7071 - 0.7071i 0.0000 - 1.0000i -0.7071 - 0.7071i -1.0000 - 0.0000i -0.7071 + 0.7071i 0.0000 + 1.0000i 0.7071 + 0.7071i
r2 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i
r3 1.0000 + 0.0000i -0.7071 - 0.7071i -0.0000 + 1.0000i 0.7071 - 0.7071i -1.0000 - 0.0000i 0.7071 + 0.7071i 0.0000 - 1.0000i -0.7071 + 0.7071i
r4 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i
r5 1.0000 + 0.0000i -0.7071 + 0.7071i 0.0000 - 1.0000i 0.7071 + 0.7071i -1.0000 - 0.0000i 0.7071 - 0.7071i -0.0000 + 1.0000i -0.7071 - 0.7071i
r6 1.0000 + 0.0000i 0.0000 + 1.0000i -1.0000 - 0.0000i 0.0000 - 1.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i -1.0000 - 0.0000i 0.0000 - 1.0000i
r7 1.0000 + 0.0000i 0.7071 + 0.7071i -0.0000 + 1.0000i -0.7071 + 0.7071i -1.0000 - 0.0000i -0.7071 - 0.7071i 0.0000 - 1.0000i 0.7071 - 0.7071i
*/
//Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
float32_t d13 = d1 + d3;
float32_t d1_3 = d1 - d3;
float32_t e13 = e1 + e3;
float32_t e57 = e5 + e7;
float32_t e1_3 = e1 - e3;
float32_t e_57 = e7 - e5;
float32_t d57 = d5 + d7;
float32_t d_57 = d7 - d5;
float32_t temp1 = ROT_CONST*(d1_3+d_57);
float32_t temp1b = ROT_CONST*(e57 - e13);
float32_t temp2 = ROT_CONST*(d57-d13);
float32_t temp2b = ROT_CONST*(e1_3 + e_57);
float32_t d04 = d0 + d4;
float32_t d0_4 = d0 - d4;
float32_t d26 = d2 + d6;
float32_t d_26 = d6 - d2;
float32_t d0246 = d04 + d26;
float32_t d1357 = d13 + d57;
float32_t e0246 = e0 + e2 + e4 + e6;
float32_t e0_4 = e0 - e4;
float32_t e0_24_6 = e0 - e2 + e4 - e6;
float32_t e1357 = e13 + e57;
float32_t e_13_57 = e_57 - e1_3;
float32_t e2_6 = e2 - e6 ;
float32_t e_26 = e6 - e2 ;
r0.re = d0246 + d1357;
//r1.re = d0 + ROT_CONST*d1 - ROT_CONST*d3 - d4 - ROT_CONST*d5 + ROT_CONST*d7;
r1.re = d0_4 + temp1;
r7.re = r1.re + (e_26 + temp1b);
r1.re = r1.re - (e_26 + temp1b);
r2.re = d04 - d26;
r6.re = r2.re + e_13_57;
r2.re = r2.re - e_13_57;
//r3.re = d0 - ROT_CONST*d1 + ROT_CONST*d3 - d4 + ROT_CONST*d5 - ROT_CONST*d7;
r3.re = d0_4 - temp1;
r5.re = r3.re + (e2_6 + temp1b);
r3.re = r3.re - (e2_6 + temp1b);
r4.re = d0246 - d1357;
//Im(c1*c2) = c1.re*c2.im + c1.im*c2.re
r0.im = e0246 + e1357;
//r1.im = -ROT_CONST*d1 - d2 - ROT_CONST*d3 + ROT_CONST*d5 + d6 + ROT_CONST*d7;
r1.im = d_26 + temp2;
r7.im = -r1.im + ( e0_4 + temp2b);
r1.im = r1.im + ( e0_4 + temp2b);
r2.im = d_57 - d1_3;
r6.im = -r2.im + e0_24_6;
r2.im = r2.im + e0_24_6;
//r3.im = -ROT_CONST*d1 + d2 - ROT_CONST*d3 + ROT_CONST*d5 - d6 + ROT_CONST*d7;
r3.im = temp2 - d_26;
r5.im = -r3.im + (e0_4 - temp2b);
r3.im = r3.im + (e0_4 - temp2b);
r4.im = e0246 - e1357;
// TWIDDLES
tw1 = twiddle_ptr[twiddle_index*1];
tw2 = twiddle_ptr[twiddle_index*2];
tw3 = twiddle_ptr[twiddle_index*3];
tw4 = twiddle_ptr[twiddle_index*4];
tw5 = twiddle_ptr[twiddle_index*5];
tw6 = twiddle_ptr[twiddle_index*6];
tw7 = twiddle_ptr[twiddle_index*7];
output[index] = r0;
output[index+distance] = complex_mul(tw1, r1);
output[index+2*distance] = complex_mul(tw2, r2);
output[index+3*distance] = complex_mul(tw3, r3);
output[index+4*distance] = complex_mul(tw4, r4);
output[index+5*distance] = complex_mul(tw5, r5);
output[index+6*distance] = complex_mul(tw6, r6);
output[index+7*distance] = complex_mul(tw7, r7);
}
static inline void process_butterfly_last_radix8 ( Complex_type_f32* input,
Complex_type_f32* output,
int outindex ) {
int index = 0;
float32_t d0, d1, d2, d3, d4, d5, d6, d7;
float32_t e0, e1, e2, e3, e4, e5, e6, e7;
Complex_type_f32 r0, r1, r2, r3, r4, r7, r6, r5 ;
d0 = input[index].re;
d1 = input[index+1].re;
d2 = input[index+2].re;
d3 = input[index+3].re;
d4 = input[index+4].re;
d5 = input[index+5].re;
d6 = input[index+6].re;
d7 = input[index+7].re;
e0 = input[index].im;
e1 = input[index+1].im;
e2 = input[index+2].im;
e3 = input[index+3].im;
e4 = input[index+4].im;
e5 = input[index+5].im;
e6 = input[index+6].im;
e7 = input[index+7].im;
/* twiddles are all 1s */
// Basic buttefly rotation
/*
r0 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i
r1 1.0000 + 0.0000i 0.7071 - 0.7071i 0.0000 - 1.0000i -0.7071 - 0.7071i -1.0000 - 0.0000i -0.7071 + 0.7071i 0.0000 + 1.0000i 0.7071 + 0.7071i
r2 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 0.0000 - 1.0000i -1.0000 - 0.0000i 0.0000 + 1.0000i
r3 1.0000 + 0.0000i -0.7071 - 0.7071i -0.0000 + 1.0000i 0.7071 - 0.7071i -1.0000 - 0.0000i 0.7071 + 0.7071i 0.0000 - 1.0000i -0.7071 + 0.7071i
r4 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i 1.0000 + 0.0000i -1.0000 - 0.0000i
r5 1.0000 + 0.0000i -0.7071 + 0.7071i 0.0000 - 1.0000i 0.7071 + 0.7071i -1.0000 - 0.0000i 0.7071 - 0.7071i -0.0000 + 1.0000i -0.7071 - 0.7071i
r6 1.0000 + 0.0000i 0.0000 + 1.0000i -1.0000 - 0.0000i 0.0000 - 1.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i -1.0000 - 0.0000i 0.0000 - 1.0000i
r7 1.0000 + 0.0000i 0.7071 + 0.7071i -0.0000 + 1.0000i -0.7071 + 0.7071i -1.0000 - 0.0000i -0.7071 - 0.7071i 0.0000 - 1.0000i 0.7071 - 0.7071i
*/
// Re(c1*c2) = c1.re*c2.re - c1.im*c2.im
float32_t d13 = d1 + d3;
float32_t d1_3 = d1 - d3;
float32_t e13 = e1 + e3;
float32_t e57 = e5 + e7;
float32_t e1_3 = e1 - e3;
float32_t e_57 = e7 - e5;
float32_t d57 = d5 + d7;
float32_t d_57 = d7 - d5;
float32_t temp1 = ROT_CONST*(d1_3+d_57);
float32_t temp1b = ROT_CONST*(e57 - e13);
float32_t temp2 = ROT_CONST*(d57-d13);
float32_t temp2b = ROT_CONST*(e1_3 + e_57);
float32_t d04 = d0 + d4;
float32_t d0_4 = d0 - d4;
float32_t d26 = d2 + d6;
float32_t d_26 = d6 - d2;
float32_t d0246 = d04 + d26;
float32_t d1357 = d13 + d57;
float32_t e0246 = e0 + e2 + e4 + e6;
float32_t e0_4 = e0 - e4;
float32_t e0_24_6 = e0 - e2 + e4 - e6;
float32_t e1357 = e13 + e57;
float32_t e_13_57 = e_57 - e1_3;
float32_t e2_6 = e2 - e6 ;
float32_t e_26 = e6 - e2 ;
r0.re = d0246 + d1357;
// r1.re = d0 + ROT_CONST*d1 - ROT_CONST*d3 - d4 - ROT_CONST*d5 + ROT_CONST*d7;
r1.re = d0_4 + temp1;
r7.re = r1.re + (e_26 + temp1b);
r1.re = r1.re - (e_26 + temp1b);
r2.re = d04 - d26;
r6.re = r2.re + e_13_57;
r2.re = r2.re - e_13_57;
// r3.re = d0 - ROT_CONST*d1 + ROT_CONST*d3 - d4 + ROT_CONST*d5 - ROT_CONST*d7;
r3.re = d0_4 - temp1;
r5.re = r3.re + (e2_6 + temp1b);
r3.re = r3.re - (e2_6 + temp1b);
r4.re = d0246 - d1357;
// Im(c1*c2) = c1.re*c2.im + c1.im*c2.re
r0.im = e0246 + e1357;
// r1.im = -ROT_CONST*d1 - d2 - ROT_CONST*d3 + ROT_CONST*d5 + d6 + ROT_CONST*d7;
r1.im = d_26 + temp2;
r7.im = -r1.im + ( e0_4 + temp2b);
r1.im = r1.im + ( e0_4 + temp2b);
r2.im = d_57 - d1_3;
r6.im = -r2.im + e0_24_6;
r2.im = r2.im + e0_24_6;
// r3.im = -ROT_CONST*d1 + d2 - ROT_CONST*d3 + ROT_CONST*d5 - d6 + ROT_CONST*d7;
r3.im = temp2 - d_26;
r5.im = -r3.im + (e0_4 - temp2b);
r3.im = r3.im + (e0_4 - temp2b);
r4.im = e0246 - e1357;
/* In the Last step, twiddle factors are all 1 */
output[outindex ] = r0;
output[outindex+1 ] = r1;
output[outindex+2*1] = r2;
output[outindex+3*1] = r3;
output[outindex+4*1] = r4;
output[outindex+5*1] = r5;
output[outindex+6*1] = r6;
output[outindex+7*1] = r7;
}
static void plp_radix8_rfft_f32s_xpulpv2( const plp_fft_instance_f32 *S,
const float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst) {
int k, j, stage, step, d, index;
Complex_type_f32 temp;
int dist = S->FFTLength >> 3;
int nbutterfly = S->FFTLength >> 3;
int butt = 8; // number of butterflies in the same group
Complex_type_f32 *_in_ptr;
Complex_type_f32 *_out_ptr;
Complex_type_f32 *_tw_ptr;
// FIRST STAGE
stage = 1;
_out_ptr = (Complex_type_f32 *)pDst;
_tw_ptr = (Complex_type_f32 *)S->pTwiddleFactors;
for (j = 0; j < nbutterfly; j++) {
process_butterfly_real_radix8(pSrc, _out_ptr, j, dist, _tw_ptr);
pSrc++;
_out_ptr++;
} // j
stage = stage + 1;
dist = dist >> 3;
// STAGES 2 -> n-1
while (dist > 1) {
step = dist << 3;
for (j = 0; j < butt; j++) {
_in_ptr = (Complex_type_f32 *)pDst;
for (d = 0; d < dist; d++) {
process_butterfly_radix8(_in_ptr, _in_ptr, d * butt, j * step, dist, _tw_ptr);
_in_ptr++;
} // d
} // j
stage = stage + 1;
dist = dist >> 3;
butt = butt << 3;
}
// LAST STAGE
_in_ptr = (Complex_type_f32 *)pDst;
index = 0;
for (j = 0; j < (S->FFTLength >> 3); j++) {
process_butterfly_last_radix8(_in_ptr, (Complex_type_f32 *)pDst, index);
_in_ptr += 8;
index += 8;
} // j
// ORDER VALUES
if (S->bitReverseFlag) {
int index1, index2, index3, index4;
_out_ptr = (Complex_type_f32 *)pDst;
for (j = 0; j < S->FFTLength; j += 4) {
if (S->pBitReverseLUT) {
unsigned int index12 = *((unsigned int *)(&S->pBitReverseLUT[j]));
unsigned int index34 = *((unsigned int *)(&S->pBitReverseLUT[j + 2]));
index1 = index12 & 0x0000FFFF;
index2 = index12 >> 16;
index3 = index34 & 0x0000FFFF;
index4 = index34 >> 16;
} else {
int log2FFTLen = log2(S->FFTLength);
index1 = bit_rev_radix8(j, log2FFTLen);
index2 = bit_rev_radix8(j + 1, log2FFTLen);
index3 = bit_rev_radix8(j + 2, log2FFTLen);
index4 = bit_rev_radix8(j + 3, log2FFTLen);
}
if (index1 > j) {
temp = _out_ptr[j];
_out_ptr[j] = _out_ptr[index1];
_out_ptr[index1] = temp;
}
if (index2 > j + 1) {
temp = _out_ptr[j + 1];
_out_ptr[j + 1] = _out_ptr[index2];
_out_ptr[index2] = temp;
}
if (index3 > j + 2) {
temp = _out_ptr[j + 2];
_out_ptr[j + 2] = _out_ptr[index3];
_out_ptr[index3] = temp;
}
if (index4 > j + 3) {
temp = _out_ptr[j + 3];
_out_ptr[j + 3] = _out_ptr[index4];
_out_ptr[index4] = temp;
}
}
}
}
/* RADIX_2_4 */
int bit_rev_2_4(int value, int log2FFTLen) {
int i;
unsigned int new_value = 0;
for (i = 0; i < (log2FFTLen - 1)/2; i++)
{
new_value <<= 2;
new_value |= (value & 0x3);
value >>= 2;
}
new_value = (new_value << 1) | value;
return new_value;
}
static void plp_radix_2by4_rfft_f32s_xpulpv2( const plp_fft_instance_f32 *S,
const float32_t *__restrict__ pSrc,
float32_t * pDst) {
int i, j;
int dist = S->FFTLength >> 1;
int nbutterfly = S->FFTLength >> 1;
Complex_type_f32 * _out_ptr;
Complex_type_f32 * _tw_ptr;
Complex_type_f32 temp;
// STAGE 1
_out_ptr = (Complex_type_f32 *)pDst;
_tw_ptr = (Complex_type_f32 *)(S->pTwiddleFactors);
for (j = 0; j < nbutterfly; j++) {
process_butterfly_real_radix2(pSrc, &_out_ptr[j], j, dist, _tw_ptr);
pSrc++;
// _out_ptr++;
}
// STAGES 2 -> n (radix-4)
_out_ptr = (Complex_type_f32 *)pDst;
for (j = 0; j < S->FFTLength; j += S->FFTLength/2) {
fft_radix4_mixed( (float32_t *)(_out_ptr + j), (float32_t *)(_out_ptr + j),
(S -> FFTLength) / 2,
S -> pTwiddleFactors);
}
if ((S -> bitReverseFlag) == 1) {
if (S -> pBitReverseLUT) {
int log2FFTLen = log2(S -> FFTLength);
for(j = 0; j < S->FFTLength; j += log2FFTLen) {
unsigned int index[log2FFTLen + 1];
unsigned int val;
// Read a sequence of permutation from the LUT
val = *((unsigned int *)(&S->pBitReverseLUT[j]));
if(val == 0) break;
index[0] = val & 0x0000FFFF;
index[1] = val >> 16;
for(int k = 2; k < log2FFTLen + 1; k += 2) {
val = *((unsigned int *)(&S->pBitReverseLUT[j + k]));
index[k] = val & 0x0000FFFF;
index[k + 1] = val >> 16;
}
// Apply permutations
temp = _out_ptr[index[log2FFTLen - 1]];
for(int k = log2FFTLen - 1; k > 0; k--) {
_out_ptr[index[k]] = _out_ptr[index[k - 1]];
}
_out_ptr[index[0]] = temp;
}
} else {
int log2FFTLen = log2(S -> FFTLength);
for(j = 0; j < S -> FFTLength; j++) {
int skip;
unsigned int index[log2FFTLen];
index[0] = j;
skip = 0;
// Find a closed set of permutations
for (int k = 0; k < log2FFTLen - 1; k++) {
index[k + 1] = bit_rev_2_4(index[k], log2FFTLen);
if (index[k + 1] > j) {
skip = 1;
break;
}
}
// Apply permutations
if (!skip) {
temp = _out_ptr[index[log2FFTLen - 1]];
for (int k = log2FFTLen - 1; k > 0; k--) {
_out_ptr[index[k]] = _out_ptr[index[k - 1]];
}
_out_ptr[index[0]] = temp;
}
}
}
}
}
static void fft_radix4_mixed( float32_t *__restrict__ pSrc,
float32_t *__restrict__ pDst,
uint32_t FFTLength,
const float32_t *pTwiddleFactors) {
int k, j, stage, step, d, index;
int dist = FFTLength >> 2;
int nbutterfly = FFTLength >> 2;
int butt = 4; // number of butterflies in the same group
Complex_type_f32 *_in_ptr;
Complex_type_f32 *_tw_ptr;
// FIRST STAGE
stage = 1;
_in_ptr = (Complex_type_f32 *)pSrc;
_tw_ptr = (Complex_type_f32 *)pTwiddleFactors;
for (j = 0; j < nbutterfly; j++) {
process_butterfly_radix4(_in_ptr, _in_ptr, 2 * j, 0, dist, _tw_ptr);
_in_ptr++;
} // j
stage = stage + 1;
dist = dist >> 2;
// STAGES 2 -> n-1
while (dist > 1) {
step = dist << 2;
for (j = 0; j < butt; j++) {
_in_ptr = (Complex_type_f32 *)pSrc;
for (d = 0; d < dist; d++) {
process_butterfly_radix4(_in_ptr, _in_ptr, 2 * d * butt, j * step, dist, _tw_ptr);
_in_ptr++;
} // d
} // j
stage = stage + 1;
dist = dist >> 2;
butt = butt << 2;
}
// LAST STAGE
_in_ptr = (Complex_type_f32 *)pSrc;
index = 0;
for (j = 0; j < (FFTLength >> 2); j++) {
process_butterfly_last_radix4(_in_ptr, (Complex_type_f32 *)pDst, index);
_in_ptr += 4;
index += 4;
} // j
}
Updated on 2023-03-01 at 16:16:33 +0000