Laxmi Kant Tiwari
CMSIS DSP Lib
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mbed official
Diff: cmsis_dsp/TransformFunctions/arm_bitreversal.c
- Revision:
- 3:7a284390b0ce
- Parent:
- 2:da51fb522205
--- a/cmsis_dsp/TransformFunctions/arm_bitreversal.c Thu May 30 17:10:11 2013 +0100
+++ b/cmsis_dsp/TransformFunctions/arm_bitreversal.c Fri Nov 08 13:45:10 2013 +0000
@@ -1,8 +1,8 @@
/* ----------------------------------------------------------------------
-* Copyright (C) 2010 ARM Limited. All rights reserved.
+* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
*
-* $Date: 15. February 2012
-* $Revision: V1.1.0
+* $Date: 17. January 2013
+* $Revision: V1.4.1
*
* Project: CMSIS DSP Library
* Title: arm_bitreversal.c
@@ -11,155 +11,175 @@
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
-* Version 1.1.0 2012/02/15
-* Updated with more optimizations, bug fixes and minor API changes.
-*
-* Version 1.0.10 2011/7/15
-* Initial Version
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions
+* are met:
+* - Redistributions of source code must retain the above copyright
+* notice, this list of conditions and the following disclaimer.
+* - Redistributions in binary form must reproduce the above copyright
+* notice, this list of conditions and the following disclaimer in
+* the documentation and/or other materials provided with the
+* distribution.
+* - Neither the name of ARM LIMITED nor the names of its contributors
+* may be used to endorse or promote products derived from this
+* software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.
* -------------------------------------------------------------------- */
#include "arm_math.h"
#include "arm_common_tables.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.
- */
+* @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.
+*/
void arm_bitreversal_f32(
- float32_t * pSrc,
- uint16_t fftSize,
- uint16_t bitRevFactor,
- uint16_t * pBitRevTab)
+float32_t * pSrc,
+uint16_t fftSize,
+uint16_t bitRevFactor,
+uint16_t * pBitRevTab)
{
- uint16_t fftLenBy2, fftLenBy2p1;
- uint16_t i, j;
- float32_t in;
+ uint16_t fftLenBy2, fftLenBy2p1;
+ uint16_t i, j;
+ float32_t in;
+
+ /* Initializations */
+ j = 0u;
+ fftLenBy2 = fftSize >> 1u;
+ fftLenBy2p1 = (fftSize >> 1u) + 1u;
- /* 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;
- /* 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) + 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;
-
- }
+ in = pSrc[2u * (i + 1u)];
+ pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
+ pSrc[2u * (j + fftLenBy2)] = 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;
- /* 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;
- /* Reading the index for the bit reversal */
- j = *pBitRevTab;
-
- /* Updating the bit reversal index depending on the fft length */
- pBitRevTab += bitRevFactor;
- }
+ /* Updating the bit reversal index depending on the fft length */
+ pBitRevTab += bitRevFactor;
+ }
}
/*
- * @brief In-place bit reversal function.
- * @param[in, out] *pSrc points to the in-place buffer of Q31 data type.
- * @param[in] fftLen 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 bit reversal table.
- * @return none.
- */
+* @brief In-place bit reversal function.
+* @param[in, out] *pSrc points to the in-place buffer of Q31 data type.
+* @param[in] fftLen 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 bit reversal table.
+* @return none.
+*/
void arm_bitreversal_q31(
- q31_t * pSrc,
- uint32_t fftLen,
- uint16_t bitRevFactor,
- uint16_t * pBitRevTable)
+q31_t * pSrc,
+uint32_t fftLen,
+uint16_t bitRevFactor,
+uint16_t * pBitRevTable)
{
- uint32_t fftLenBy2, fftLenBy2p1, i, j;
- q31_t in;
+ uint32_t fftLenBy2, fftLenBy2p1, i, j;
+ q31_t in;
+
+ /* Initializations */
+ j = 0u;
+ fftLenBy2 = fftLen / 2u;
+ fftLenBy2p1 = (fftLen / 2u) + 1u;
- /* Initializations */
- j = 0u;
- fftLenBy2 = fftLen / 2u;
- fftLenBy2p1 = (fftLen / 2u) + 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;
- /* 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) + 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;
-
- }
+ in = pSrc[2u * (i + 1u)];
+ pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
+ pSrc[2u * (j + fftLenBy2)] = 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;
- /* 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 = *pBitRevTable;
- /* Reading the index for the bit reversal */
- j = *pBitRevTable;
-
- /* Updating the bit reversal index depending on the fft length */
- pBitRevTable += bitRevFactor;
- }
+ /* Updating the bit reversal index depending on the fft length */
+ pBitRevTable += bitRevFactor;
+ }
}
@@ -171,52 +191,52 @@
* @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table
* @param[in] *pBitRevTab points to bit reversal table.
* @return none.
- */
+*/
void arm_bitreversal_q15(
- q15_t * pSrc16,
- uint32_t fftLen,
- uint16_t bitRevFactor,
- uint16_t * pBitRevTab)
+q15_t * pSrc16,
+uint32_t fftLen,
+uint16_t bitRevFactor,
+uint16_t * pBitRevTab)
{
- q31_t *pSrc = (q31_t *) pSrc16;
- q31_t in;
- uint32_t fftLenBy2, fftLenBy2p1;
- uint32_t i, j;
+ q31_t *pSrc = (q31_t *) pSrc16;
+ q31_t in;
+ uint32_t fftLenBy2, fftLenBy2p1;
+ uint32_t i, j;
- /* Initializations */
- j = 0u;
- fftLenBy2 = fftLen / 2u;
- fftLenBy2p1 = (fftLen / 2u) + 1u;
+ /* Initializations */
+ j = 0u;
+ fftLenBy2 = fftLen / 2u;
+ fftLenBy2p1 = (fftLen / 2u) + 1u;
- /* Bit Reversal Implementation */
- for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
- {
- if(i < j)
- {
- /* pSrc[i] <-> pSrc[j]; */
- /* pSrc[i+1u] <-> pSrc[j+1u] */
- in = pSrc[i];
- pSrc[i] = pSrc[j];
- pSrc[j] = in;
+ /* Bit Reversal Implementation */
+ for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
+ {
+ if(i < j)
+ {
+ /* pSrc[i] <-> pSrc[j]; */
+ /* pSrc[i+1u] <-> pSrc[j+1u] */
+ in = pSrc[i];
+ pSrc[i] = pSrc[j];
+ pSrc[j] = in;
- /* pSrc[i + fftLenBy2p1] <-> pSrc[j + fftLenBy2p1]; */
- /* pSrc[i + fftLenBy2p1+1u] <-> pSrc[j + fftLenBy2p1+1u] */
- in = pSrc[i + fftLenBy2p1];
- pSrc[i + fftLenBy2p1] = pSrc[j + fftLenBy2p1];
- pSrc[j + fftLenBy2p1] = in;
- }
+ /* pSrc[i + fftLenBy2p1] <-> pSrc[j + fftLenBy2p1]; */
+ /* pSrc[i + fftLenBy2p1+1u] <-> pSrc[j + fftLenBy2p1+1u] */
+ in = pSrc[i + fftLenBy2p1];
+ pSrc[i + fftLenBy2p1] = pSrc[j + fftLenBy2p1];
+ pSrc[j + fftLenBy2p1] = in;
+ }
- /* pSrc[i+1u] <-> pSrc[j+fftLenBy2]; */
- /* pSrc[i+2] <-> pSrc[j+fftLenBy2+1u] */
- in = pSrc[i + 1u];
- pSrc[i + 1u] = pSrc[j + fftLenBy2];
- pSrc[j + fftLenBy2] = in;
+ /* pSrc[i+1u] <-> pSrc[j+fftLenBy2]; */
+ /* pSrc[i+2] <-> pSrc[j+fftLenBy2+1u] */
+ in = pSrc[i + 1u];
+ pSrc[i + 1u] = pSrc[j + fftLenBy2];
+ pSrc[j + fftLenBy2] = in;
- /* Reading the index for the bit reversal */
- j = *pBitRevTab;
+ /* Reading the index for the bit reversal */
+ j = *pBitRevTab;
- /* Updating the bit reversal index depending on the fft length */
- pBitRevTab += bitRevFactor;
- }
+ /* Updating the bit reversal index depending on the fft length */
+ pBitRevTab += bitRevFactor;
+ }
}