init
This commit is contained in:
@@ -0,0 +1,102 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_bitreversal_f16.c
|
||||
* Description: Bitreversal functions
|
||||
*
|
||||
* $Date: 23 April 2021
|
||||
* $Revision: V1.9.0
|
||||
*
|
||||
* Target Processor: Cortex-M and Cortex-A cores
|
||||
* -------------------------------------------------------------------- */
|
||||
/*
|
||||
* Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
|
||||
*
|
||||
* 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 "dsp/transform_functions_f16.h"
|
||||
|
||||
/*
|
||||
* @brief In-place bit reversal function.
|
||||
* @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
|
||||
* @param[in] fftSize length of the FFT.
|
||||
* @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table.
|
||||
* @param[in] *pBitRevTab points to the bit reversal table.
|
||||
* @return none.
|
||||
*/
|
||||
|
||||
#if defined(ARM_FLOAT16_SUPPORTED)
|
||||
|
||||
void arm_bitreversal_f16(
|
||||
float16_t * pSrc,
|
||||
uint16_t fftSize,
|
||||
uint16_t bitRevFactor,
|
||||
const uint16_t * pBitRevTab)
|
||||
{
|
||||
uint16_t fftLenBy2, fftLenBy2p1;
|
||||
uint16_t i, j;
|
||||
float16_t in;
|
||||
|
||||
/* Initializations */
|
||||
j = 0U;
|
||||
fftLenBy2 = fftSize >> 1U;
|
||||
fftLenBy2p1 = (fftSize >> 1U) + 1U;
|
||||
|
||||
/* Bit Reversal Implementation */
|
||||
for (i = 0U; i <= (fftLenBy2 - 2U); i += 2U)
|
||||
{
|
||||
if (i < j)
|
||||
{
|
||||
/* pSrc[i] <-> pSrc[j]; */
|
||||
in = pSrc[2U * i];
|
||||
pSrc[2U * i] = pSrc[2U * j];
|
||||
pSrc[2U * j] = in;
|
||||
|
||||
/* pSrc[i+1U] <-> pSrc[j+1U] */
|
||||
in = pSrc[(2U * i) + 1U];
|
||||
pSrc[(2U * i) + 1U] = pSrc[(2U * j) + 1U];
|
||||
pSrc[(2U * j) + 1U] = in;
|
||||
|
||||
/* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
|
||||
in = pSrc[2U * (i + fftLenBy2p1)];
|
||||
pSrc[2U * (i + fftLenBy2p1)] = pSrc[2U * (j + fftLenBy2p1)];
|
||||
pSrc[2U * (j + fftLenBy2p1)] = in;
|
||||
|
||||
/* pSrc[i+fftLenBy2p1+1U] <-> pSrc[j+fftLenBy2p1+1U] */
|
||||
in = pSrc[(2U * (i + fftLenBy2p1)) + 1U];
|
||||
pSrc[(2U * (i + fftLenBy2p1)) + 1U] =
|
||||
pSrc[(2U * (j + fftLenBy2p1)) + 1U];
|
||||
pSrc[(2U * (j + fftLenBy2p1)) + 1U] = in;
|
||||
|
||||
}
|
||||
|
||||
/* pSrc[i+1U] <-> pSrc[j+1U] */
|
||||
in = pSrc[2U * (i + 1U)];
|
||||
pSrc[2U * (i + 1U)] = pSrc[2U * (j + fftLenBy2)];
|
||||
pSrc[2U * (j + fftLenBy2)] = in;
|
||||
|
||||
/* pSrc[i+2U] <-> pSrc[j+2U] */
|
||||
in = pSrc[(2U * (i + 1U)) + 1U];
|
||||
pSrc[(2U * (i + 1U)) + 1U] = pSrc[(2U * (j + fftLenBy2)) + 1U];
|
||||
pSrc[(2U * (j + fftLenBy2)) + 1U] = in;
|
||||
|
||||
/* Reading the index for the bit reversal */
|
||||
j = *pBitRevTab;
|
||||
|
||||
/* Updating the bit reversal index depending on the fft length */
|
||||
pBitRevTab += bitRevFactor;
|
||||
}
|
||||
}
|
||||
#endif /* #if defined(ARM_FLOAT16_SUPPORTED) */
|
||||
Reference in New Issue
Block a user