/github/workspace/src/TransformFunctions/kernels/plp_cfft_q32s_rv32im.c
Functions
| Name | |
|---|---|
| void | plp_cfft_radix4by2_q32(int32_t * pSrc, uint32_t fftLen, const int32_t * pCoef) |
| void | plp_radix4_butterfly_q32(int32_t * pSrc, uint32_t fftLen, int32_t * pCoef, uint32_t twidCoefModifier) |
| void | plp_cfft_q32s_rv32im(const plp_cfft_instance_q32 * S, int32_t * p1, uint8_t ifftFlag, uint8_t bitReverseFlag, uint32_t fracBits) Quantized 32-bit complex fast fourier transform for RV32IM. |
Defines
| Name | |
|---|---|
| multAcc_32x32_keep32_R(a, x, y) | |
| multSub_32x32_keep32_R(a, x, y) | |
| mult_32x32_keep32_R(a, x, y) |
Functions Documentation
function plp_cfft_radix4by2_q32
static void plp_cfft_radix4by2_q32(
int32_t * pSrc,
uint32_t fftLen,
const int32_t * pCoef
)
function plp_radix4_butterfly_q32
static void plp_radix4_butterfly_q32(
int32_t * pSrc,
uint32_t fftLen,
int32_t * pCoef,
uint32_t twidCoefModifier
)
function plp_cfft_q32s_rv32im
void plp_cfft_q32s_rv32im(
const plp_cfft_instance_q32 * S,
int32_t * p1,
uint8_t ifftFlag,
uint8_t bitReverseFlag,
uint32_t fracBits
)
Quantized 32-bit complex fast fourier transform for RV32IM.
Parameters:
- S points to an instance of the 32bit quantized CFFT structure
- p1 points to the complex data buffer of size
2*fftLen. Processing occurs in-place. - ifftFlag flag that selects forwart (ifftFlag=0) or inverse (ifftFlag=1)
- bitReverseFlag flag that enables (bitReverseFlag=1) of disables (bitReverseFlag=0) bit reversal of output.
- fracBits decimal point for right shift (input format Q(32-fracBits).fracBits)
Macros Documentation
define multAcc_32x32_keep32_R
#define multAcc_32x32_keep32_R(
a,
x,
y
)
a = (int32_t) (((((int64_t) a) << 32) + ((int64_t) x * y) + 0x80000000LL ) >> 32)
define multSub_32x32_keep32_R
#define multSub_32x32_keep32_R(
a,
x,
y
)
a = (int32_t) (((((int64_t) a) << 32) - ((int64_t) x * y) + 0x80000000LL ) >> 32)
define mult_32x32_keep32_R
#define mult_32x32_keep32_R(
a,
x,
y
)
a = (int32_t) (((int64_t) x * y + 0x80000000LL ) >> 32)
Source code
/* =====================================================================
* Project: PULP DSP Library
* Title: plp_cfft_q32s_rv32im.c
* Description: 32-bit fixed point Fast Fourier Transform on Compled Input Data
*
* $Date: 30. July 2020
* $Revision: V0
*
* Target Processor: PULP cores
* ===================================================================== */
/*
* Copyright (C) 2020 ETH Zurich and University of Bologna. All rights reserved.
*
* Author: Michael Rogenmoser, ETH Zurich
*
* 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"
#define multAcc_32x32_keep32_R(a, x, y) \
a = (int32_t) (((((int64_t) a) << 32) + ((int64_t) x * y) + 0x80000000LL ) >> 32)
#define multSub_32x32_keep32_R(a, x, y) \
a = (int32_t) (((((int64_t) a) << 32) - ((int64_t) x * y) + 0x80000000LL ) >> 32)
#define mult_32x32_keep32_R(a, x, y) \
a = (int32_t) (((int64_t) x * y + 0x80000000LL ) >> 32)
static void plp_cfft_radix4by2_q32(int32_t *pSrc, uint32_t fftLen, const int32_t *pCoef);
static void plp_radix4_butterfly_q32(int32_t *pSrc,
uint32_t fftLen,
int32_t *pCoef,
uint32_t twidCoefModifier);
void plp_cfft_q32s_rv32im(const plp_cfft_instance_q32 *S,
int32_t *p1,
uint8_t ifftFlag,
uint8_t bitReverseFlag,
uint32_t fracBits){
uint32_t L = S->fftLen;
if (ifftFlag == 0) {
switch (L) {
case 16:
case 64:
case 256:
case 1024:
case 4096:
plp_radix4_butterfly_q32(p1, L, (int32_t *)S->pTwiddle, 1);
break;
case 32:
case 128:
case 512:
case 2048:
plp_cfft_radix4by2_q32(p1, L, (int32_t *)S->pTwiddle);
break;
}
}
if (bitReverseFlag)
plp_bitreversal_32s_rv32im((uint32_t *)p1, S->bitRevLength, S->pBitRevTable);
}
void plp_cfft_radix4by2_q32(int32_t *pSrc, uint32_t fftLen, const int32_t *pCoef){
uint32_t i, l;
uint32_t n2;
int32_t xt, yt, cosVal, sinVal;
int32_t p0, p1;
n2 = fftLen >> 1U;
for (i = 0; i < n2; i++)
{
cosVal = pCoef[2 * i];
sinVal = pCoef[2 * i + 1];
l = i + n2;
xt = (pSrc[2 * i] >> 2U) - (pSrc[2 * l] >> 2U);
pSrc[2 * i] = (pSrc[2 * i] >> 2U) + (pSrc[2 * l] >> 2U);
yt = (pSrc[2 * i + 1] >> 2U) - (pSrc[2 * l + 1] >> 2U);
pSrc[2 * i + 1] = (pSrc[2 * l + 1] >> 2U) + (pSrc[2 * i + 1] >> 2U);
mult_32x32_keep32_R(p0, xt, cosVal);
mult_32x32_keep32_R(p1, yt, cosVal);
multAcc_32x32_keep32_R(p0, yt, sinVal);
multSub_32x32_keep32_R(p1, xt, sinVal);
pSrc[2 * l] = p0 << 1;
pSrc[2 * l + 1] = p1 << 1;
}
/* first col */
plp_radix4_butterfly_q32 (pSrc, n2, (int32_t*)pCoef, 2U);
/* second col */
plp_radix4_butterfly_q32 (pSrc + fftLen, n2, (int32_t*)pCoef, 2U);
n2 = fftLen >> 1U;
for (i = 0; i < n2; i++)
{
p0 = pSrc[4 * i + 0];
p1 = pSrc[4 * i + 1];
xt = pSrc[4 * i + 2];
yt = pSrc[4 * i + 3];
p0 <<= 1U;
p1 <<= 1U;
xt <<= 1U;
yt <<= 1U;
pSrc[4 * i + 0] = p0;
pSrc[4 * i + 1] = p1;
pSrc[4 * i + 2] = xt;
pSrc[4 * i + 3] = yt;
}
}
void plp_radix4_butterfly_q32(int32_t *pSrc,
uint32_t fftLen,
int32_t *pCoef,
uint32_t twidCoefModifier){
uint32_t n1, n2, ia1, ia2, ia3, i0, i1, i2, i3, j, k;
int32_t t1, t2, r1, r2, s1, s2, co1, co2, co3, si1, si2, si3;
int32_t xa, xb, xc, xd;
int32_t ya, yb, yc, yd;
int32_t xa_out, xb_out, xc_out, xd_out;
int32_t ya_out, yb_out, yc_out, yd_out;
int32_t *ptr1;
/* Total process is divided into three stages */
/* process first stage, middle stages, & last stage */
/* start of first stage process */
/* Initializations for the first stage */
n2 = fftLen;
n1 = n2;
/* n2 = fftLen/4 */
n2 >>= 2U;
i0 = 0U;
ia1 = 0U;
j = n2;
/* Calculation of first stage */
do
{
/* index calculation for the input as, */
/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2U], pSrc[i0 + 3fftLen/4] */
i1 = i0 + n2;
i2 = i1 + n2;
i3 = i2 + n2;
/* input is in 1.31(q31) format and provide 4 guard bits for the input */
/* Butterfly implementation */
/* xa + xc */
r1 = (pSrc[(2U * i0)] >> 4U) + (pSrc[(2U * i2)] >> 4U);
/* xa - xc */
r2 = (pSrc[(2U * i0)] >> 4U) - (pSrc[(2U * i2)] >> 4U);
/* xb + xd */
t1 = (pSrc[(2U * i1)] >> 4U) + (pSrc[(2U * i3)] >> 4U);
/* ya + yc */
s1 = (pSrc[(2U * i0) + 1U] >> 4U) + (pSrc[(2U * i2) + 1U] >> 4U);
/* ya - yc */
s2 = (pSrc[(2U * i0) + 1U] >> 4U) - (pSrc[(2U * i2) + 1U] >> 4U);
/* xa' = xa + xb + xc + xd */
pSrc[2U * i0] = (r1 + t1);
/* (xa + xc) - (xb + xd) */
r1 = r1 - t1;
/* yb + yd */
t2 = (pSrc[(2U * i1) + 1U] >> 4U) + (pSrc[(2U * i3) + 1U] >> 4U);
/* ya' = ya + yb + yc + yd */
pSrc[(2U * i0) + 1U] = (s1 + t2);
/* (ya + yc) - (yb + yd) */
s1 = s1 - t2;
/* yb - yd */
t1 = (pSrc[(2U * i1) + 1U] >> 4U) - (pSrc[(2U * i3) + 1U] >> 4U);
/* xb - xd */
t2 = (pSrc[(2U * i1)] >> 4U) - (pSrc[(2U * i3)] >> 4U);
/* index calculation for the coefficients */
ia2 = 2U * ia1;
co2 = pCoef[(ia2 * 2U)];
si2 = pCoef[(ia2 * 2U) + 1U];
/* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
pSrc[2U * i1] = (((int32_t) (((int64_t) r1 * co2) >> 32)) +
((int32_t) (((int64_t) s1 * si2) >> 32))) << 1U;
/* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
pSrc[(2U * i1) + 1U] = (((int32_t) (((int64_t) s1 * co2) >> 32)) -
((int32_t) (((int64_t) r1 * si2) >> 32))) << 1U;
/* (xa - xc) + (yb - yd) */
r1 = r2 + t1;
/* (xa - xc) - (yb - yd) */
r2 = r2 - t1;
/* (ya - yc) - (xb - xd) */
s1 = s2 - t2;
/* (ya - yc) + (xb - xd) */
s2 = s2 + t2;
co1 = pCoef[(ia1 * 2U)];
si1 = pCoef[(ia1 * 2U) + 1U];
/* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
pSrc[2U * i2] = (((int32_t) (((int64_t) r1 * co1) >> 32)) +
((int32_t) (((int64_t) s1 * si1) >> 32))) << 1U;
/* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
pSrc[(2U * i2) + 1U] = (((int32_t) (((int64_t) s1 * co1) >> 32)) -
((int32_t) (((int64_t) r1 * si1) >> 32))) << 1U;
/* index calculation for the coefficients */
ia3 = 3U * ia1;
co3 = pCoef[(ia3 * 2U)];
si3 = pCoef[(ia3 * 2U) + 1U];
/* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
pSrc[2U * i3] = (((int32_t) (((int64_t) r2 * co3) >> 32)) +
((int32_t) (((int64_t) s2 * si3) >> 32))) << 1U;
/* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
pSrc[(2U * i3) + 1U] = (((int32_t) (((int64_t) s2 * co3) >> 32)) -
((int32_t) (((int64_t) r2 * si3) >> 32))) << 1U;
/* Twiddle coefficients index modifier */
ia1 = ia1 + twidCoefModifier;
/* Updating input index */
i0 = i0 + 1U;
} while (--j);
/* end of first stage process */
/* data is in 5.27(q27) format */
/* start of Middle stages process */
/* each stage in middle stages provides two down scaling of the input */
twidCoefModifier <<= 2U;
for (k = fftLen / 4U; k > 4U; k >>= 2U)
{
/* Initializations for the first stage */
n1 = n2;
n2 >>= 2U;
ia1 = 0U;
/* Calculation of first stage */
for (j = 0U; j <= (n2 - 1U); j++)
{
/* index calculation for the coefficients */
ia2 = ia1 + ia1;
ia3 = ia2 + ia1;
co1 = pCoef[(ia1 * 2U)];
si1 = pCoef[(ia1 * 2U) + 1U];
co2 = pCoef[(ia2 * 2U)];
si2 = pCoef[(ia2 * 2U) + 1U];
co3 = pCoef[(ia3 * 2U)];
si3 = pCoef[(ia3 * 2U) + 1U];
/* Twiddle coefficients index modifier */
ia1 = ia1 + twidCoefModifier;
for (i0 = j; i0 < fftLen; i0 += n1)
{
/* index calculation for the input as, */
/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2U], pSrc[i0 + 3fftLen/4] */
i1 = i0 + n2;
i2 = i1 + n2;
i3 = i2 + n2;
/* Butterfly implementation */
/* xa + xc */
r1 = pSrc[2U * i0] + pSrc[2U * i2];
/* xa - xc */
r2 = pSrc[2U * i0] - pSrc[2U * i2];
/* ya + yc */
s1 = pSrc[(2U * i0) + 1U] + pSrc[(2U * i2) + 1U];
/* ya - yc */
s2 = pSrc[(2U * i0) + 1U] - pSrc[(2U * i2) + 1U];
/* xb + xd */
t1 = pSrc[2U * i1] + pSrc[2U * i3];
/* xa' = xa + xb + xc + xd */
pSrc[2U * i0] = (r1 + t1) >> 2U;
/* xa + xc -(xb + xd) */
r1 = r1 - t1;
/* yb + yd */
t2 = pSrc[(2U * i1) + 1U] + pSrc[(2U * i3) + 1U];
/* ya' = ya + yb + yc + yd */
pSrc[(2U * i0) + 1U] = (s1 + t2) >> 2U;
/* (ya + yc) - (yb + yd) */
s1 = s1 - t2;
/* (yb - yd) */
t1 = pSrc[(2U * i1) + 1U] - pSrc[(2U * i3) + 1U];
/* (xb - xd) */
t2 = pSrc[2U * i1] - pSrc[2U * i3];
/* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
pSrc[2U * i1] = (((int32_t) (((int64_t) r1 * co2) >> 32)) +
((int32_t) (((int64_t) s1 * si2) >> 32))) >> 1U;
/* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
pSrc[(2U * i1) + 1U] = (((int32_t) (((int64_t) s1 * co2) >> 32)) -
((int32_t) (((int64_t) r1 * si2) >> 32))) >> 1U;
/* (xa - xc) + (yb - yd) */
r1 = r2 + t1;
/* (xa - xc) - (yb - yd) */
r2 = r2 - t1;
/* (ya - yc) - (xb - xd) */
s1 = s2 - t2;
/* (ya - yc) + (xb - xd) */
s2 = s2 + t2;
/* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
pSrc[2U * i2] = (((int32_t) (((int64_t) r1 * co1) >> 32)) +
((int32_t) (((int64_t) s1 * si1) >> 32))) >> 1U;
/* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
pSrc[(2U * i2) + 1U] = (((int32_t) (((int64_t) s1 * co1) >> 32)) -
((int32_t) (((int64_t) r1 * si1) >> 32))) >> 1U;
/* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
pSrc[2U * i3] = (((int32_t) (((int64_t) r2 * co3) >> 32)) +
((int32_t) (((int64_t) s2 * si3) >> 32))) >> 1U;
/* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
pSrc[(2U * i3) + 1U] = (((int32_t) (((int64_t) s2 * co3) >> 32)) -
((int32_t) (((int64_t) r2 * si3) >> 32))) >> 1U;
}
}
twidCoefModifier <<= 2U;
}
/* End of Middle stages process */
/* data is in 11.21(q21) format for the 1024 point as there are 3 middle stages */
/* data is in 9.23(q23) format for the 256 point as there are 2 middle stages */
/* data is in 7.25(q25) format for the 64 point as there are 1 middle stage */
/* data is in 5.27(q27) format for the 16 point as there are no middle stages */
/* start of Last stage process */
/* Initializations for the last stage */
j = fftLen >> 2;
ptr1 = &pSrc[0];
/* Calculations of last stage */
do
{
/* Read xa (real), ya(imag) input */
xa = *ptr1++;
ya = *ptr1++;
/* Read xb (real), yb(imag) input */
xb = *ptr1++;
yb = *ptr1++;
/* Read xc (real), yc(imag) input */
xc = *ptr1++;
yc = *ptr1++;
/* Read xc (real), yc(imag) input */
xd = *ptr1++;
yd = *ptr1++;
/* xa' = xa + xb + xc + xd */
xa_out = xa + xb + xc + xd;
/* ya' = ya + yb + yc + yd */
ya_out = ya + yb + yc + yd;
/* pointer updation for writing */
ptr1 = ptr1 - 8U;
/* writing xa' and ya' */
*ptr1++ = xa_out;
*ptr1++ = ya_out;
xc_out = (xa - xb + xc - xd);
yc_out = (ya - yb + yc - yd);
/* writing xc' and yc' */
*ptr1++ = xc_out;
*ptr1++ = yc_out;
xb_out = (xa + yb - xc - yd);
yb_out = (ya - xb - yc + xd);
/* writing xb' and yb' */
*ptr1++ = xb_out;
*ptr1++ = yb_out;
xd_out = (xa - yb - xc + yd);
yd_out = (ya + xb - yc - xd);
/* writing xd' and yd' */
*ptr1++ = xd_out;
*ptr1++ = yd_out;
} while (--j);
/* output is in 11.21(q21) format for the 1024 point */
/* output is in 9.23(q23) format for the 256 point */
/* output is in 7.25(q25) format for the 64 point */
/* output is in 5.27(q27) format for the 16 point */
/* End of last stage process */
}
Updated on 2023-03-01 at 16:16:33 +0000