Eli Hughes / CMSIS_DSP_401

V4.0.1 of the ARM CMSIS DSP libraries. Note that arm_bitreversal2.s, arm_cfft_f32.c and arm_rfft_fast_f32.c had to be removed. arm_bitreversal2.s will not assemble with the online tools. So, the fast f32 FFT functions are not yet available. All the other FFT functions are available.

Dependents:   MPU9150_Example fir_f32 fir_f32 MPU9150_nucleo_noni2cdev ... more

FilteringFunctions/arm_correlate_f32.c@0:3d9c67d97d6f, 2014-07-28 (annotated)

Committer:
emh203
Date:
Mon Jul 28 15:03:15 2014 +0000
Revision:
0:3d9c67d97d6f
1st working commit.   Had to remove arm_bitreversal2.s     arm_cfft_f32.c and arm_rfft_fast_f32.c.    The .s will not assemble.      For now I removed these functions so we could at least have a library for the other functions.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emh203 0:3d9c67d97d6f 1 /* ----------------------------------------------------------------------------
emh203 0:3d9c67d97d6f 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
emh203 0:3d9c67d97d6f 3 *
emh203 0:3d9c67d97d6f 4 * $Date: 12. March 2014
emh203 0:3d9c67d97d6f 5 * $Revision: V1.4.3
emh203 0:3d9c67d97d6f 6 *
emh203 0:3d9c67d97d6f 7 * Project: CMSIS DSP Library
emh203 0:3d9c67d97d6f 8 * Title: arm_correlate_f32.c
emh203 0:3d9c67d97d6f 9 *
emh203 0:3d9c67d97d6f 10 * Description: Correlation of floating-point sequences.
emh203 0:3d9c67d97d6f 11 *
emh203 0:3d9c67d97d6f 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emh203 0:3d9c67d97d6f 13 *
emh203 0:3d9c67d97d6f 14 * Redistribution and use in source and binary forms, with or without
emh203 0:3d9c67d97d6f 15 * modification, are permitted provided that the following conditions
emh203 0:3d9c67d97d6f 16 * are met:
emh203 0:3d9c67d97d6f 17 * - Redistributions of source code must retain the above copyright
emh203 0:3d9c67d97d6f 18 * notice, this list of conditions and the following disclaimer.
emh203 0:3d9c67d97d6f 19 * - Redistributions in binary form must reproduce the above copyright
emh203 0:3d9c67d97d6f 20 * notice, this list of conditions and the following disclaimer in
emh203 0:3d9c67d97d6f 21 * the documentation and/or other materials provided with the
emh203 0:3d9c67d97d6f 22 * distribution.
emh203 0:3d9c67d97d6f 23 * - Neither the name of ARM LIMITED nor the names of its contributors
emh203 0:3d9c67d97d6f 24 * may be used to endorse or promote products derived from this
emh203 0:3d9c67d97d6f 25 * software without specific prior written permission.
emh203 0:3d9c67d97d6f 26 *
emh203 0:3d9c67d97d6f 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
emh203 0:3d9c67d97d6f 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
emh203 0:3d9c67d97d6f 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
emh203 0:3d9c67d97d6f 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
emh203 0:3d9c67d97d6f 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
emh203 0:3d9c67d97d6f 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
emh203 0:3d9c67d97d6f 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
emh203 0:3d9c67d97d6f 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
emh203 0:3d9c67d97d6f 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
emh203 0:3d9c67d97d6f 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
emh203 0:3d9c67d97d6f 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
emh203 0:3d9c67d97d6f 38 * POSSIBILITY OF SUCH DAMAGE.
emh203 0:3d9c67d97d6f 39 * -------------------------------------------------------------------------- */
emh203 0:3d9c67d97d6f 40
emh203 0:3d9c67d97d6f 41 #include "arm_math.h"
emh203 0:3d9c67d97d6f 42
emh203 0:3d9c67d97d6f 43 /**
emh203 0:3d9c67d97d6f 44 * @ingroup groupFilters
emh203 0:3d9c67d97d6f 45 */
emh203 0:3d9c67d97d6f 46
emh203 0:3d9c67d97d6f 47 /**
emh203 0:3d9c67d97d6f 48 * @defgroup Corr Correlation
emh203 0:3d9c67d97d6f 49 *
emh203 0:3d9c67d97d6f 50 * Correlation is a mathematical operation that is similar to convolution.
emh203 0:3d9c67d97d6f 51 * As with convolution, correlation uses two signals to produce a third signal.
emh203 0:3d9c67d97d6f 52 * The underlying algorithms in correlation and convolution are identical except that one of the inputs is flipped in convolution.
emh203 0:3d9c67d97d6f 53 * Correlation is commonly used to measure the similarity between two signals.
emh203 0:3d9c67d97d6f 54 * It has applications in pattern recognition, cryptanalysis, and searching.
emh203 0:3d9c67d97d6f 55 * The CMSIS library provides correlation functions for Q7, Q15, Q31 and floating-point data types.
emh203 0:3d9c67d97d6f 56 * Fast versions of the Q15 and Q31 functions are also provided.
emh203 0:3d9c67d97d6f 57 *
emh203 0:3d9c67d97d6f 58 * \par Algorithm
emh203 0:3d9c67d97d6f 59 * Let <code>a[n]</code> and <code>b[n]</code> be sequences of length <code>srcALen</code> and <code>srcBLen</code> samples respectively.
emh203 0:3d9c67d97d6f 60 * The convolution of the two signals is denoted by
emh203 0:3d9c67d97d6f 61 * <pre>
emh203 0:3d9c67d97d6f 62 * c[n] = a[n] * b[n]
emh203 0:3d9c67d97d6f 63 * </pre>
emh203 0:3d9c67d97d6f 64 * In correlation, one of the signals is flipped in time
emh203 0:3d9c67d97d6f 65 * <pre>
emh203 0:3d9c67d97d6f 66 * c[n] = a[n] * b[-n]
emh203 0:3d9c67d97d6f 67 * </pre>
emh203 0:3d9c67d97d6f 68 *
emh203 0:3d9c67d97d6f 69 * \par
emh203 0:3d9c67d97d6f 70 * and this is mathematically defined as
emh203 0:3d9c67d97d6f 71 * \image html CorrelateEquation.gif
emh203 0:3d9c67d97d6f 72 * \par
emh203 0:3d9c67d97d6f 73 * The <code>pSrcA</code> points to the first input vector of length <code>srcALen</code> and <code>pSrcB</code> points to the second input vector of length <code>srcBLen</code>.
emh203 0:3d9c67d97d6f 74 * The result <code>c[n]</code> is of length <code>2 * max(srcALen, srcBLen) - 1</code> and is defined over the interval <code>n=0, 1, 2, ..., (2 * max(srcALen, srcBLen) - 2)</code>.
emh203 0:3d9c67d97d6f 75 * The output result is written to <code>pDst</code> and the calling function must allocate <code>2 * max(srcALen, srcBLen) - 1</code> words for the result.
emh203 0:3d9c67d97d6f 76 *
emh203 0:3d9c67d97d6f 77 * <b>Note</b>
emh203 0:3d9c67d97d6f 78 * \par
emh203 0:3d9c67d97d6f 79 * The <code>pDst</code> should be initialized to all zeros before being used.
emh203 0:3d9c67d97d6f 80 *
emh203 0:3d9c67d97d6f 81 * <b>Fixed-Point Behavior</b>
emh203 0:3d9c67d97d6f 82 * \par
emh203 0:3d9c67d97d6f 83 * Correlation requires summing up a large number of intermediate products.
emh203 0:3d9c67d97d6f 84 * As such, the Q7, Q15, and Q31 functions run a risk of overflow and saturation.
emh203 0:3d9c67d97d6f 85 * Refer to the function specific documentation below for further details of the particular algorithm used.
emh203 0:3d9c67d97d6f 86 *
emh203 0:3d9c67d97d6f 87 *
emh203 0:3d9c67d97d6f 88 * <b>Fast Versions</b>
emh203 0:3d9c67d97d6f 89 *
emh203 0:3d9c67d97d6f 90 * \par
emh203 0:3d9c67d97d6f 91 * Fast versions are supported for Q31 and Q15. Cycles for Fast versions are less compared to Q31 and Q15 of correlate and the design requires
emh203 0:3d9c67d97d6f 92 * the input signals should be scaled down to avoid intermediate overflows.
emh203 0:3d9c67d97d6f 93 *
emh203 0:3d9c67d97d6f 94 *
emh203 0:3d9c67d97d6f 95 * <b>Opt Versions</b>
emh203 0:3d9c67d97d6f 96 *
emh203 0:3d9c67d97d6f 97 * \par
emh203 0:3d9c67d97d6f 98 * Opt versions are supported for Q15 and Q7. Design uses internal scratch buffer for getting good optimisation.
emh203 0:3d9c67d97d6f 99 * These versions are optimised in cycles and consumes more memory(Scratch memory) compared to Q15 and Q7 versions of correlate
emh203 0:3d9c67d97d6f 100 */
emh203 0:3d9c67d97d6f 101
emh203 0:3d9c67d97d6f 102 /**
emh203 0:3d9c67d97d6f 103 * @addtogroup Corr
emh203 0:3d9c67d97d6f 104 * @{
emh203 0:3d9c67d97d6f 105 */
emh203 0:3d9c67d97d6f 106 /**
emh203 0:3d9c67d97d6f 107 * @brief Correlation of floating-point sequences.
emh203 0:3d9c67d97d6f 108 * @param[in] *pSrcA points to the first input sequence.
emh203 0:3d9c67d97d6f 109 * @param[in] srcALen length of the first input sequence.
emh203 0:3d9c67d97d6f 110 * @param[in] *pSrcB points to the second input sequence.
emh203 0:3d9c67d97d6f 111 * @param[in] srcBLen length of the second input sequence.
emh203 0:3d9c67d97d6f 112 * @param[out] *pDst points to the location where the output result is written. Length 2 * max(srcALen, srcBLen) - 1.
emh203 0:3d9c67d97d6f 113 * @return none.
emh203 0:3d9c67d97d6f 114 */
emh203 0:3d9c67d97d6f 115
emh203 0:3d9c67d97d6f 116 void arm_correlate_f32(
emh203 0:3d9c67d97d6f 117 float32_t * pSrcA,
emh203 0:3d9c67d97d6f 118 uint32_t srcALen,
emh203 0:3d9c67d97d6f 119 float32_t * pSrcB,
emh203 0:3d9c67d97d6f 120 uint32_t srcBLen,
emh203 0:3d9c67d97d6f 121 float32_t * pDst)
emh203 0:3d9c67d97d6f 122 {
emh203 0:3d9c67d97d6f 123
emh203 0:3d9c67d97d6f 124
emh203 0:3d9c67d97d6f 125 #ifndef ARM_MATH_CM0_FAMILY
emh203 0:3d9c67d97d6f 126
emh203 0:3d9c67d97d6f 127 /* Run the below code for Cortex-M4 and Cortex-M3 */
emh203 0:3d9c67d97d6f 128
emh203 0:3d9c67d97d6f 129 float32_t *pIn1; /* inputA pointer */
emh203 0:3d9c67d97d6f 130 float32_t *pIn2; /* inputB pointer */
emh203 0:3d9c67d97d6f 131 float32_t *pOut = pDst; /* output pointer */
emh203 0:3d9c67d97d6f 132 float32_t *px; /* Intermediate inputA pointer */
emh203 0:3d9c67d97d6f 133 float32_t *py; /* Intermediate inputB pointer */
emh203 0:3d9c67d97d6f 134 float32_t *pSrc1; /* Intermediate pointers */
emh203 0:3d9c67d97d6f 135 float32_t sum, acc0, acc1, acc2, acc3; /* Accumulators */
emh203 0:3d9c67d97d6f 136 float32_t x0, x1, x2, x3, c0; /* temporary variables for holding input and coefficient values */
emh203 0:3d9c67d97d6f 137 uint32_t j, k = 0u, count, blkCnt, outBlockSize, blockSize1, blockSize2, blockSize3; /* loop counters */
emh203 0:3d9c67d97d6f 138 int32_t inc = 1; /* Destination address modifier */
emh203 0:3d9c67d97d6f 139
emh203 0:3d9c67d97d6f 140
emh203 0:3d9c67d97d6f 141 /* The algorithm implementation is based on the lengths of the inputs. */
emh203 0:3d9c67d97d6f 142 /* srcB is always made to slide across srcA. */
emh203 0:3d9c67d97d6f 143 /* So srcBLen is always considered as shorter or equal to srcALen */
emh203 0:3d9c67d97d6f 144 /* But CORR(x, y) is reverse of CORR(y, x) */
emh203 0:3d9c67d97d6f 145 /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */
emh203 0:3d9c67d97d6f 146 /* and the destination pointer modifier, inc is set to -1 */
emh203 0:3d9c67d97d6f 147 /* If srcALen > srcBLen, zero pad has to be done to srcB to make the two inputs of same length */
emh203 0:3d9c67d97d6f 148 /* But to improve the performance,
emh203 0:3d9c67d97d6f 149 * we assume zeroes in the output instead of zero padding either of the the inputs*/
emh203 0:3d9c67d97d6f 150 /* If srcALen > srcBLen,
emh203 0:3d9c67d97d6f 151 * (srcALen - srcBLen) zeroes has to included in the starting of the output buffer */
emh203 0:3d9c67d97d6f 152 /* If srcALen < srcBLen,
emh203 0:3d9c67d97d6f 153 * (srcALen - srcBLen) zeroes has to included in the ending of the output buffer */
emh203 0:3d9c67d97d6f 154 if(srcALen >= srcBLen)
emh203 0:3d9c67d97d6f 155 {
emh203 0:3d9c67d97d6f 156 /* Initialization of inputA pointer */
emh203 0:3d9c67d97d6f 157 pIn1 = pSrcA;
emh203 0:3d9c67d97d6f 158
emh203 0:3d9c67d97d6f 159 /* Initialization of inputB pointer */
emh203 0:3d9c67d97d6f 160 pIn2 = pSrcB;
emh203 0:3d9c67d97d6f 161
emh203 0:3d9c67d97d6f 162 /* Number of output samples is calculated */
emh203 0:3d9c67d97d6f 163 outBlockSize = (2u * srcALen) - 1u;
emh203 0:3d9c67d97d6f 164
emh203 0:3d9c67d97d6f 165 /* When srcALen > srcBLen, zero padding has to be done to srcB
emh203 0:3d9c67d97d6f 166 * to make their lengths equal.
emh203 0:3d9c67d97d6f 167 * Instead, (outBlockSize - (srcALen + srcBLen - 1))
emh203 0:3d9c67d97d6f 168 * number of output samples are made zero */
emh203 0:3d9c67d97d6f 169 j = outBlockSize - (srcALen + (srcBLen - 1u));
emh203 0:3d9c67d97d6f 170
emh203 0:3d9c67d97d6f 171 /* Updating the pointer position to non zero value */
emh203 0:3d9c67d97d6f 172 pOut += j;
emh203 0:3d9c67d97d6f 173
emh203 0:3d9c67d97d6f 174 //while(j > 0u)
emh203 0:3d9c67d97d6f 175 //{
emh203 0:3d9c67d97d6f 176 // /* Zero is stored in the destination buffer */
emh203 0:3d9c67d97d6f 177 // *pOut++ = 0.0f;
emh203 0:3d9c67d97d6f 178
emh203 0:3d9c67d97d6f 179 // /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 180 // j--;
emh203 0:3d9c67d97d6f 181 //}
emh203 0:3d9c67d97d6f 182
emh203 0:3d9c67d97d6f 183 }
emh203 0:3d9c67d97d6f 184 else
emh203 0:3d9c67d97d6f 185 {
emh203 0:3d9c67d97d6f 186 /* Initialization of inputA pointer */
emh203 0:3d9c67d97d6f 187 pIn1 = pSrcB;
emh203 0:3d9c67d97d6f 188
emh203 0:3d9c67d97d6f 189 /* Initialization of inputB pointer */
emh203 0:3d9c67d97d6f 190 pIn2 = pSrcA;
emh203 0:3d9c67d97d6f 191
emh203 0:3d9c67d97d6f 192 /* srcBLen is always considered as shorter or equal to srcALen */
emh203 0:3d9c67d97d6f 193 j = srcBLen;
emh203 0:3d9c67d97d6f 194 srcBLen = srcALen;
emh203 0:3d9c67d97d6f 195 srcALen = j;
emh203 0:3d9c67d97d6f 196
emh203 0:3d9c67d97d6f 197 /* CORR(x, y) = Reverse order(CORR(y, x)) */
emh203 0:3d9c67d97d6f 198 /* Hence set the destination pointer to point to the last output sample */
emh203 0:3d9c67d97d6f 199 pOut = pDst + ((srcALen + srcBLen) - 2u);
emh203 0:3d9c67d97d6f 200
emh203 0:3d9c67d97d6f 201 /* Destination address modifier is set to -1 */
emh203 0:3d9c67d97d6f 202 inc = -1;
emh203 0:3d9c67d97d6f 203
emh203 0:3d9c67d97d6f 204 }
emh203 0:3d9c67d97d6f 205
emh203 0:3d9c67d97d6f 206 /* The function is internally
emh203 0:3d9c67d97d6f 207 * divided into three parts according to the number of multiplications that has to be
emh203 0:3d9c67d97d6f 208 * taken place between inputA samples and inputB samples. In the first part of the
emh203 0:3d9c67d97d6f 209 * algorithm, the multiplications increase by one for every iteration.
emh203 0:3d9c67d97d6f 210 * In the second part of the algorithm, srcBLen number of multiplications are done.
emh203 0:3d9c67d97d6f 211 * In the third part of the algorithm, the multiplications decrease by one
emh203 0:3d9c67d97d6f 212 * for every iteration.*/
emh203 0:3d9c67d97d6f 213 /* The algorithm is implemented in three stages.
emh203 0:3d9c67d97d6f 214 * The loop counters of each stage is initiated here. */
emh203 0:3d9c67d97d6f 215 blockSize1 = srcBLen - 1u;
emh203 0:3d9c67d97d6f 216 blockSize2 = srcALen - (srcBLen - 1u);
emh203 0:3d9c67d97d6f 217 blockSize3 = blockSize1;
emh203 0:3d9c67d97d6f 218
emh203 0:3d9c67d97d6f 219 /* --------------------------
emh203 0:3d9c67d97d6f 220 * Initializations of stage1
emh203 0:3d9c67d97d6f 221 * -------------------------*/
emh203 0:3d9c67d97d6f 222
emh203 0:3d9c67d97d6f 223 /* sum = x[0] * y[srcBlen - 1]
emh203 0:3d9c67d97d6f 224 * sum = x[0] * y[srcBlen-2] + x[1] * y[srcBlen - 1]
emh203 0:3d9c67d97d6f 225 * ....
emh203 0:3d9c67d97d6f 226 * sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen - 1] * y[srcBLen - 1]
emh203 0:3d9c67d97d6f 227 */
emh203 0:3d9c67d97d6f 228
emh203 0:3d9c67d97d6f 229 /* In this stage the MAC operations are increased by 1 for every iteration.
emh203 0:3d9c67d97d6f 230 The count variable holds the number of MAC operations performed */
emh203 0:3d9c67d97d6f 231 count = 1u;
emh203 0:3d9c67d97d6f 232
emh203 0:3d9c67d97d6f 233 /* Working pointer of inputA */
emh203 0:3d9c67d97d6f 234 px = pIn1;
emh203 0:3d9c67d97d6f 235
emh203 0:3d9c67d97d6f 236 /* Working pointer of inputB */
emh203 0:3d9c67d97d6f 237 pSrc1 = pIn2 + (srcBLen - 1u);
emh203 0:3d9c67d97d6f 238 py = pSrc1;
emh203 0:3d9c67d97d6f 239
emh203 0:3d9c67d97d6f 240 /* ------------------------
emh203 0:3d9c67d97d6f 241 * Stage1 process
emh203 0:3d9c67d97d6f 242 * ----------------------*/
emh203 0:3d9c67d97d6f 243
emh203 0:3d9c67d97d6f 244 /* The first stage starts here */
emh203 0:3d9c67d97d6f 245 while(blockSize1 > 0u)
emh203 0:3d9c67d97d6f 246 {
emh203 0:3d9c67d97d6f 247 /* Accumulator is made zero for every iteration */
emh203 0:3d9c67d97d6f 248 sum = 0.0f;
emh203 0:3d9c67d97d6f 249
emh203 0:3d9c67d97d6f 250 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emh203 0:3d9c67d97d6f 251 k = count >> 2u;
emh203 0:3d9c67d97d6f 252
emh203 0:3d9c67d97d6f 253 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emh203 0:3d9c67d97d6f 254 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emh203 0:3d9c67d97d6f 255 while(k > 0u)
emh203 0:3d9c67d97d6f 256 {
emh203 0:3d9c67d97d6f 257 /* x[0] * y[srcBLen - 4] */
emh203 0:3d9c67d97d6f 258 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 259 /* x[1] * y[srcBLen - 3] */
emh203 0:3d9c67d97d6f 260 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 261 /* x[2] * y[srcBLen - 2] */
emh203 0:3d9c67d97d6f 262 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 263 /* x[3] * y[srcBLen - 1] */
emh203 0:3d9c67d97d6f 264 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 265
emh203 0:3d9c67d97d6f 266 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 267 k--;
emh203 0:3d9c67d97d6f 268 }
emh203 0:3d9c67d97d6f 269
emh203 0:3d9c67d97d6f 270 /* If the count is not a multiple of 4, compute any remaining MACs here.
emh203 0:3d9c67d97d6f 271 ** No loop unrolling is used. */
emh203 0:3d9c67d97d6f 272 k = count % 0x4u;
emh203 0:3d9c67d97d6f 273
emh203 0:3d9c67d97d6f 274 while(k > 0u)
emh203 0:3d9c67d97d6f 275 {
emh203 0:3d9c67d97d6f 276 /* Perform the multiply-accumulate */
emh203 0:3d9c67d97d6f 277 /* x[0] * y[srcBLen - 1] */
emh203 0:3d9c67d97d6f 278 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 279
emh203 0:3d9c67d97d6f 280 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 281 k--;
emh203 0:3d9c67d97d6f 282 }
emh203 0:3d9c67d97d6f 283
emh203 0:3d9c67d97d6f 284 /* Store the result in the accumulator in the destination buffer. */
emh203 0:3d9c67d97d6f 285 *pOut = sum;
emh203 0:3d9c67d97d6f 286 /* Destination pointer is updated according to the address modifier, inc */
emh203 0:3d9c67d97d6f 287 pOut += inc;
emh203 0:3d9c67d97d6f 288
emh203 0:3d9c67d97d6f 289 /* Update the inputA and inputB pointers for next MAC calculation */
emh203 0:3d9c67d97d6f 290 py = pSrc1 - count;
emh203 0:3d9c67d97d6f 291 px = pIn1;
emh203 0:3d9c67d97d6f 292
emh203 0:3d9c67d97d6f 293 /* Increment the MAC count */
emh203 0:3d9c67d97d6f 294 count++;
emh203 0:3d9c67d97d6f 295
emh203 0:3d9c67d97d6f 296 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 297 blockSize1--;
emh203 0:3d9c67d97d6f 298 }
emh203 0:3d9c67d97d6f 299
emh203 0:3d9c67d97d6f 300 /* --------------------------
emh203 0:3d9c67d97d6f 301 * Initializations of stage2
emh203 0:3d9c67d97d6f 302 * ------------------------*/
emh203 0:3d9c67d97d6f 303
emh203 0:3d9c67d97d6f 304 /* sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen-1] * y[srcBLen-1]
emh203 0:3d9c67d97d6f 305 * sum = x[1] * y[0] + x[2] * y[1] +...+ x[srcBLen] * y[srcBLen-1]
emh203 0:3d9c67d97d6f 306 * ....
emh203 0:3d9c67d97d6f 307 * sum = x[srcALen-srcBLen-2] * y[0] + x[srcALen-srcBLen-1] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
emh203 0:3d9c67d97d6f 308 */
emh203 0:3d9c67d97d6f 309
emh203 0:3d9c67d97d6f 310 /* Working pointer of inputA */
emh203 0:3d9c67d97d6f 311 px = pIn1;
emh203 0:3d9c67d97d6f 312
emh203 0:3d9c67d97d6f 313 /* Working pointer of inputB */
emh203 0:3d9c67d97d6f 314 py = pIn2;
emh203 0:3d9c67d97d6f 315
emh203 0:3d9c67d97d6f 316 /* count is index by which the pointer pIn1 to be incremented */
emh203 0:3d9c67d97d6f 317 count = 0u;
emh203 0:3d9c67d97d6f 318
emh203 0:3d9c67d97d6f 319 /* -------------------
emh203 0:3d9c67d97d6f 320 * Stage2 process
emh203 0:3d9c67d97d6f 321 * ------------------*/
emh203 0:3d9c67d97d6f 322
emh203 0:3d9c67d97d6f 323 /* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed.
emh203 0:3d9c67d97d6f 324 * So, to loop unroll over blockSize2,
emh203 0:3d9c67d97d6f 325 * srcBLen should be greater than or equal to 4, to loop unroll the srcBLen loop */
emh203 0:3d9c67d97d6f 326 if(srcBLen >= 4u)
emh203 0:3d9c67d97d6f 327 {
emh203 0:3d9c67d97d6f 328 /* Loop unroll over blockSize2, by 4 */
emh203 0:3d9c67d97d6f 329 blkCnt = blockSize2 >> 2u;
emh203 0:3d9c67d97d6f 330
emh203 0:3d9c67d97d6f 331 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 332 {
emh203 0:3d9c67d97d6f 333 /* Set all accumulators to zero */
emh203 0:3d9c67d97d6f 334 acc0 = 0.0f;
emh203 0:3d9c67d97d6f 335 acc1 = 0.0f;
emh203 0:3d9c67d97d6f 336 acc2 = 0.0f;
emh203 0:3d9c67d97d6f 337 acc3 = 0.0f;
emh203 0:3d9c67d97d6f 338
emh203 0:3d9c67d97d6f 339 /* read x[0], x[1], x[2] samples */
emh203 0:3d9c67d97d6f 340 x0 = *(px++);
emh203 0:3d9c67d97d6f 341 x1 = *(px++);
emh203 0:3d9c67d97d6f 342 x2 = *(px++);
emh203 0:3d9c67d97d6f 343
emh203 0:3d9c67d97d6f 344 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emh203 0:3d9c67d97d6f 345 k = srcBLen >> 2u;
emh203 0:3d9c67d97d6f 346
emh203 0:3d9c67d97d6f 347 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emh203 0:3d9c67d97d6f 348 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emh203 0:3d9c67d97d6f 349 do
emh203 0:3d9c67d97d6f 350 {
emh203 0:3d9c67d97d6f 351 /* Read y[0] sample */
emh203 0:3d9c67d97d6f 352 c0 = *(py++);
emh203 0:3d9c67d97d6f 353
emh203 0:3d9c67d97d6f 354 /* Read x[3] sample */
emh203 0:3d9c67d97d6f 355 x3 = *(px++);
emh203 0:3d9c67d97d6f 356
emh203 0:3d9c67d97d6f 357 /* Perform the multiply-accumulate */
emh203 0:3d9c67d97d6f 358 /* acc0 += x[0] * y[0] */
emh203 0:3d9c67d97d6f 359 acc0 += x0 * c0;
emh203 0:3d9c67d97d6f 360 /* acc1 += x[1] * y[0] */
emh203 0:3d9c67d97d6f 361 acc1 += x1 * c0;
emh203 0:3d9c67d97d6f 362 /* acc2 += x[2] * y[0] */
emh203 0:3d9c67d97d6f 363 acc2 += x2 * c0;
emh203 0:3d9c67d97d6f 364 /* acc3 += x[3] * y[0] */
emh203 0:3d9c67d97d6f 365 acc3 += x3 * c0;
emh203 0:3d9c67d97d6f 366
emh203 0:3d9c67d97d6f 367 /* Read y[1] sample */
emh203 0:3d9c67d97d6f 368 c0 = *(py++);
emh203 0:3d9c67d97d6f 369
emh203 0:3d9c67d97d6f 370 /* Read x[4] sample */
emh203 0:3d9c67d97d6f 371 x0 = *(px++);
emh203 0:3d9c67d97d6f 372
emh203 0:3d9c67d97d6f 373 /* Perform the multiply-accumulate */
emh203 0:3d9c67d97d6f 374 /* acc0 += x[1] * y[1] */
emh203 0:3d9c67d97d6f 375 acc0 += x1 * c0;
emh203 0:3d9c67d97d6f 376 /* acc1 += x[2] * y[1] */
emh203 0:3d9c67d97d6f 377 acc1 += x2 * c0;
emh203 0:3d9c67d97d6f 378 /* acc2 += x[3] * y[1] */
emh203 0:3d9c67d97d6f 379 acc2 += x3 * c0;
emh203 0:3d9c67d97d6f 380 /* acc3 += x[4] * y[1] */
emh203 0:3d9c67d97d6f 381 acc3 += x0 * c0;
emh203 0:3d9c67d97d6f 382
emh203 0:3d9c67d97d6f 383 /* Read y[2] sample */
emh203 0:3d9c67d97d6f 384 c0 = *(py++);
emh203 0:3d9c67d97d6f 385
emh203 0:3d9c67d97d6f 386 /* Read x[5] sample */
emh203 0:3d9c67d97d6f 387 x1 = *(px++);
emh203 0:3d9c67d97d6f 388
emh203 0:3d9c67d97d6f 389 /* Perform the multiply-accumulates */
emh203 0:3d9c67d97d6f 390 /* acc0 += x[2] * y[2] */
emh203 0:3d9c67d97d6f 391 acc0 += x2 * c0;
emh203 0:3d9c67d97d6f 392 /* acc1 += x[3] * y[2] */
emh203 0:3d9c67d97d6f 393 acc1 += x3 * c0;
emh203 0:3d9c67d97d6f 394 /* acc2 += x[4] * y[2] */
emh203 0:3d9c67d97d6f 395 acc2 += x0 * c0;
emh203 0:3d9c67d97d6f 396 /* acc3 += x[5] * y[2] */
emh203 0:3d9c67d97d6f 397 acc3 += x1 * c0;
emh203 0:3d9c67d97d6f 398
emh203 0:3d9c67d97d6f 399 /* Read y[3] sample */
emh203 0:3d9c67d97d6f 400 c0 = *(py++);
emh203 0:3d9c67d97d6f 401
emh203 0:3d9c67d97d6f 402 /* Read x[6] sample */
emh203 0:3d9c67d97d6f 403 x2 = *(px++);
emh203 0:3d9c67d97d6f 404
emh203 0:3d9c67d97d6f 405 /* Perform the multiply-accumulates */
emh203 0:3d9c67d97d6f 406 /* acc0 += x[3] * y[3] */
emh203 0:3d9c67d97d6f 407 acc0 += x3 * c0;
emh203 0:3d9c67d97d6f 408 /* acc1 += x[4] * y[3] */
emh203 0:3d9c67d97d6f 409 acc1 += x0 * c0;
emh203 0:3d9c67d97d6f 410 /* acc2 += x[5] * y[3] */
emh203 0:3d9c67d97d6f 411 acc2 += x1 * c0;
emh203 0:3d9c67d97d6f 412 /* acc3 += x[6] * y[3] */
emh203 0:3d9c67d97d6f 413 acc3 += x2 * c0;
emh203 0:3d9c67d97d6f 414
emh203 0:3d9c67d97d6f 415
emh203 0:3d9c67d97d6f 416 } while(--k);
emh203 0:3d9c67d97d6f 417
emh203 0:3d9c67d97d6f 418 /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
emh203 0:3d9c67d97d6f 419 ** No loop unrolling is used. */
emh203 0:3d9c67d97d6f 420 k = srcBLen % 0x4u;
emh203 0:3d9c67d97d6f 421
emh203 0:3d9c67d97d6f 422 while(k > 0u)
emh203 0:3d9c67d97d6f 423 {
emh203 0:3d9c67d97d6f 424 /* Read y[4] sample */
emh203 0:3d9c67d97d6f 425 c0 = *(py++);
emh203 0:3d9c67d97d6f 426
emh203 0:3d9c67d97d6f 427 /* Read x[7] sample */
emh203 0:3d9c67d97d6f 428 x3 = *(px++);
emh203 0:3d9c67d97d6f 429
emh203 0:3d9c67d97d6f 430 /* Perform the multiply-accumulates */
emh203 0:3d9c67d97d6f 431 /* acc0 += x[4] * y[4] */
emh203 0:3d9c67d97d6f 432 acc0 += x0 * c0;
emh203 0:3d9c67d97d6f 433 /* acc1 += x[5] * y[4] */
emh203 0:3d9c67d97d6f 434 acc1 += x1 * c0;
emh203 0:3d9c67d97d6f 435 /* acc2 += x[6] * y[4] */
emh203 0:3d9c67d97d6f 436 acc2 += x2 * c0;
emh203 0:3d9c67d97d6f 437 /* acc3 += x[7] * y[4] */
emh203 0:3d9c67d97d6f 438 acc3 += x3 * c0;
emh203 0:3d9c67d97d6f 439
emh203 0:3d9c67d97d6f 440 /* Reuse the present samples for the next MAC */
emh203 0:3d9c67d97d6f 441 x0 = x1;
emh203 0:3d9c67d97d6f 442 x1 = x2;
emh203 0:3d9c67d97d6f 443 x2 = x3;
emh203 0:3d9c67d97d6f 444
emh203 0:3d9c67d97d6f 445 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 446 k--;
emh203 0:3d9c67d97d6f 447 }
emh203 0:3d9c67d97d6f 448
emh203 0:3d9c67d97d6f 449 /* Store the result in the accumulator in the destination buffer. */
emh203 0:3d9c67d97d6f 450 *pOut = acc0;
emh203 0:3d9c67d97d6f 451 /* Destination pointer is updated according to the address modifier, inc */
emh203 0:3d9c67d97d6f 452 pOut += inc;
emh203 0:3d9c67d97d6f 453
emh203 0:3d9c67d97d6f 454 *pOut = acc1;
emh203 0:3d9c67d97d6f 455 pOut += inc;
emh203 0:3d9c67d97d6f 456
emh203 0:3d9c67d97d6f 457 *pOut = acc2;
emh203 0:3d9c67d97d6f 458 pOut += inc;
emh203 0:3d9c67d97d6f 459
emh203 0:3d9c67d97d6f 460 *pOut = acc3;
emh203 0:3d9c67d97d6f 461 pOut += inc;
emh203 0:3d9c67d97d6f 462
emh203 0:3d9c67d97d6f 463 /* Increment the pointer pIn1 index, count by 4 */
emh203 0:3d9c67d97d6f 464 count += 4u;
emh203 0:3d9c67d97d6f 465
emh203 0:3d9c67d97d6f 466 /* Update the inputA and inputB pointers for next MAC calculation */
emh203 0:3d9c67d97d6f 467 px = pIn1 + count;
emh203 0:3d9c67d97d6f 468 py = pIn2;
emh203 0:3d9c67d97d6f 469
emh203 0:3d9c67d97d6f 470 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 471 blkCnt--;
emh203 0:3d9c67d97d6f 472 }
emh203 0:3d9c67d97d6f 473
emh203 0:3d9c67d97d6f 474 /* If the blockSize2 is not a multiple of 4, compute any remaining output samples here.
emh203 0:3d9c67d97d6f 475 ** No loop unrolling is used. */
emh203 0:3d9c67d97d6f 476 blkCnt = blockSize2 % 0x4u;
emh203 0:3d9c67d97d6f 477
emh203 0:3d9c67d97d6f 478 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 479 {
emh203 0:3d9c67d97d6f 480 /* Accumulator is made zero for every iteration */
emh203 0:3d9c67d97d6f 481 sum = 0.0f;
emh203 0:3d9c67d97d6f 482
emh203 0:3d9c67d97d6f 483 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emh203 0:3d9c67d97d6f 484 k = srcBLen >> 2u;
emh203 0:3d9c67d97d6f 485
emh203 0:3d9c67d97d6f 486 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emh203 0:3d9c67d97d6f 487 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emh203 0:3d9c67d97d6f 488 while(k > 0u)
emh203 0:3d9c67d97d6f 489 {
emh203 0:3d9c67d97d6f 490 /* Perform the multiply-accumulates */
emh203 0:3d9c67d97d6f 491 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 492 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 493 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 494 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 495
emh203 0:3d9c67d97d6f 496 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 497 k--;
emh203 0:3d9c67d97d6f 498 }
emh203 0:3d9c67d97d6f 499
emh203 0:3d9c67d97d6f 500 /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
emh203 0:3d9c67d97d6f 501 ** No loop unrolling is used. */
emh203 0:3d9c67d97d6f 502 k = srcBLen % 0x4u;
emh203 0:3d9c67d97d6f 503
emh203 0:3d9c67d97d6f 504 while(k > 0u)
emh203 0:3d9c67d97d6f 505 {
emh203 0:3d9c67d97d6f 506 /* Perform the multiply-accumulate */
emh203 0:3d9c67d97d6f 507 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 508
emh203 0:3d9c67d97d6f 509 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 510 k--;
emh203 0:3d9c67d97d6f 511 }
emh203 0:3d9c67d97d6f 512
emh203 0:3d9c67d97d6f 513 /* Store the result in the accumulator in the destination buffer. */
emh203 0:3d9c67d97d6f 514 *pOut = sum;
emh203 0:3d9c67d97d6f 515 /* Destination pointer is updated according to the address modifier, inc */
emh203 0:3d9c67d97d6f 516 pOut += inc;
emh203 0:3d9c67d97d6f 517
emh203 0:3d9c67d97d6f 518 /* Increment the pointer pIn1 index, count by 1 */
emh203 0:3d9c67d97d6f 519 count++;
emh203 0:3d9c67d97d6f 520
emh203 0:3d9c67d97d6f 521 /* Update the inputA and inputB pointers for next MAC calculation */
emh203 0:3d9c67d97d6f 522 px = pIn1 + count;
emh203 0:3d9c67d97d6f 523 py = pIn2;
emh203 0:3d9c67d97d6f 524
emh203 0:3d9c67d97d6f 525 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 526 blkCnt--;
emh203 0:3d9c67d97d6f 527 }
emh203 0:3d9c67d97d6f 528 }
emh203 0:3d9c67d97d6f 529 else
emh203 0:3d9c67d97d6f 530 {
emh203 0:3d9c67d97d6f 531 /* If the srcBLen is not a multiple of 4,
emh203 0:3d9c67d97d6f 532 * the blockSize2 loop cannot be unrolled by 4 */
emh203 0:3d9c67d97d6f 533 blkCnt = blockSize2;
emh203 0:3d9c67d97d6f 534
emh203 0:3d9c67d97d6f 535 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 536 {
emh203 0:3d9c67d97d6f 537 /* Accumulator is made zero for every iteration */
emh203 0:3d9c67d97d6f 538 sum = 0.0f;
emh203 0:3d9c67d97d6f 539
emh203 0:3d9c67d97d6f 540 /* Loop over srcBLen */
emh203 0:3d9c67d97d6f 541 k = srcBLen;
emh203 0:3d9c67d97d6f 542
emh203 0:3d9c67d97d6f 543 while(k > 0u)
emh203 0:3d9c67d97d6f 544 {
emh203 0:3d9c67d97d6f 545 /* Perform the multiply-accumulate */
emh203 0:3d9c67d97d6f 546 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 547
emh203 0:3d9c67d97d6f 548 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 549 k--;
emh203 0:3d9c67d97d6f 550 }
emh203 0:3d9c67d97d6f 551
emh203 0:3d9c67d97d6f 552 /* Store the result in the accumulator in the destination buffer. */
emh203 0:3d9c67d97d6f 553 *pOut = sum;
emh203 0:3d9c67d97d6f 554 /* Destination pointer is updated according to the address modifier, inc */
emh203 0:3d9c67d97d6f 555 pOut += inc;
emh203 0:3d9c67d97d6f 556
emh203 0:3d9c67d97d6f 557 /* Increment the pointer pIn1 index, count by 1 */
emh203 0:3d9c67d97d6f 558 count++;
emh203 0:3d9c67d97d6f 559
emh203 0:3d9c67d97d6f 560 /* Update the inputA and inputB pointers for next MAC calculation */
emh203 0:3d9c67d97d6f 561 px = pIn1 + count;
emh203 0:3d9c67d97d6f 562 py = pIn2;
emh203 0:3d9c67d97d6f 563
emh203 0:3d9c67d97d6f 564 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 565 blkCnt--;
emh203 0:3d9c67d97d6f 566 }
emh203 0:3d9c67d97d6f 567 }
emh203 0:3d9c67d97d6f 568
emh203 0:3d9c67d97d6f 569 /* --------------------------
emh203 0:3d9c67d97d6f 570 * Initializations of stage3
emh203 0:3d9c67d97d6f 571 * -------------------------*/
emh203 0:3d9c67d97d6f 572
emh203 0:3d9c67d97d6f 573 /* sum += x[srcALen-srcBLen+1] * y[0] + x[srcALen-srcBLen+2] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
emh203 0:3d9c67d97d6f 574 * sum += x[srcALen-srcBLen+2] * y[0] + x[srcALen-srcBLen+3] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
emh203 0:3d9c67d97d6f 575 * ....
emh203 0:3d9c67d97d6f 576 * sum += x[srcALen-2] * y[0] + x[srcALen-1] * y[1]
emh203 0:3d9c67d97d6f 577 * sum += x[srcALen-1] * y[0]
emh203 0:3d9c67d97d6f 578 */
emh203 0:3d9c67d97d6f 579
emh203 0:3d9c67d97d6f 580 /* In this stage the MAC operations are decreased by 1 for every iteration.
emh203 0:3d9c67d97d6f 581 The count variable holds the number of MAC operations performed */
emh203 0:3d9c67d97d6f 582 count = srcBLen - 1u;
emh203 0:3d9c67d97d6f 583
emh203 0:3d9c67d97d6f 584 /* Working pointer of inputA */
emh203 0:3d9c67d97d6f 585 pSrc1 = pIn1 + (srcALen - (srcBLen - 1u));
emh203 0:3d9c67d97d6f 586 px = pSrc1;
emh203 0:3d9c67d97d6f 587
emh203 0:3d9c67d97d6f 588 /* Working pointer of inputB */
emh203 0:3d9c67d97d6f 589 py = pIn2;
emh203 0:3d9c67d97d6f 590
emh203 0:3d9c67d97d6f 591 /* -------------------
emh203 0:3d9c67d97d6f 592 * Stage3 process
emh203 0:3d9c67d97d6f 593 * ------------------*/
emh203 0:3d9c67d97d6f 594
emh203 0:3d9c67d97d6f 595 while(blockSize3 > 0u)
emh203 0:3d9c67d97d6f 596 {
emh203 0:3d9c67d97d6f 597 /* Accumulator is made zero for every iteration */
emh203 0:3d9c67d97d6f 598 sum = 0.0f;
emh203 0:3d9c67d97d6f 599
emh203 0:3d9c67d97d6f 600 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emh203 0:3d9c67d97d6f 601 k = count >> 2u;
emh203 0:3d9c67d97d6f 602
emh203 0:3d9c67d97d6f 603 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emh203 0:3d9c67d97d6f 604 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emh203 0:3d9c67d97d6f 605 while(k > 0u)
emh203 0:3d9c67d97d6f 606 {
emh203 0:3d9c67d97d6f 607 /* Perform the multiply-accumulates */
emh203 0:3d9c67d97d6f 608 /* sum += x[srcALen - srcBLen + 4] * y[3] */
emh203 0:3d9c67d97d6f 609 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 610 /* sum += x[srcALen - srcBLen + 3] * y[2] */
emh203 0:3d9c67d97d6f 611 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 612 /* sum += x[srcALen - srcBLen + 2] * y[1] */
emh203 0:3d9c67d97d6f 613 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 614 /* sum += x[srcALen - srcBLen + 1] * y[0] */
emh203 0:3d9c67d97d6f 615 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 616
emh203 0:3d9c67d97d6f 617 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 618 k--;
emh203 0:3d9c67d97d6f 619 }
emh203 0:3d9c67d97d6f 620
emh203 0:3d9c67d97d6f 621 /* If the count is not a multiple of 4, compute any remaining MACs here.
emh203 0:3d9c67d97d6f 622 ** No loop unrolling is used. */
emh203 0:3d9c67d97d6f 623 k = count % 0x4u;
emh203 0:3d9c67d97d6f 624
emh203 0:3d9c67d97d6f 625 while(k > 0u)
emh203 0:3d9c67d97d6f 626 {
emh203 0:3d9c67d97d6f 627 /* Perform the multiply-accumulates */
emh203 0:3d9c67d97d6f 628 sum += *px++ * *py++;
emh203 0:3d9c67d97d6f 629
emh203 0:3d9c67d97d6f 630 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 631 k--;
emh203 0:3d9c67d97d6f 632 }
emh203 0:3d9c67d97d6f 633
emh203 0:3d9c67d97d6f 634 /* Store the result in the accumulator in the destination buffer. */
emh203 0:3d9c67d97d6f 635 *pOut = sum;
emh203 0:3d9c67d97d6f 636 /* Destination pointer is updated according to the address modifier, inc */
emh203 0:3d9c67d97d6f 637 pOut += inc;
emh203 0:3d9c67d97d6f 638
emh203 0:3d9c67d97d6f 639 /* Update the inputA and inputB pointers for next MAC calculation */
emh203 0:3d9c67d97d6f 640 px = ++pSrc1;
emh203 0:3d9c67d97d6f 641 py = pIn2;
emh203 0:3d9c67d97d6f 642
emh203 0:3d9c67d97d6f 643 /* Decrement the MAC count */
emh203 0:3d9c67d97d6f 644 count--;
emh203 0:3d9c67d97d6f 645
emh203 0:3d9c67d97d6f 646 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 647 blockSize3--;
emh203 0:3d9c67d97d6f 648 }
emh203 0:3d9c67d97d6f 649
emh203 0:3d9c67d97d6f 650 #else
emh203 0:3d9c67d97d6f 651
emh203 0:3d9c67d97d6f 652 /* Run the below code for Cortex-M0 */
emh203 0:3d9c67d97d6f 653
emh203 0:3d9c67d97d6f 654 float32_t *pIn1 = pSrcA; /* inputA pointer */
emh203 0:3d9c67d97d6f 655 float32_t *pIn2 = pSrcB + (srcBLen - 1u); /* inputB pointer */
emh203 0:3d9c67d97d6f 656 float32_t sum; /* Accumulator */
emh203 0:3d9c67d97d6f 657 uint32_t i = 0u, j; /* loop counters */
emh203 0:3d9c67d97d6f 658 uint32_t inv = 0u; /* Reverse order flag */
emh203 0:3d9c67d97d6f 659 uint32_t tot = 0u; /* Length */
emh203 0:3d9c67d97d6f 660
emh203 0:3d9c67d97d6f 661 /* The algorithm implementation is based on the lengths of the inputs. */
emh203 0:3d9c67d97d6f 662 /* srcB is always made to slide across srcA. */
emh203 0:3d9c67d97d6f 663 /* So srcBLen is always considered as shorter or equal to srcALen */
emh203 0:3d9c67d97d6f 664 /* But CORR(x, y) is reverse of CORR(y, x) */
emh203 0:3d9c67d97d6f 665 /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */
emh203 0:3d9c67d97d6f 666 /* and a varaible, inv is set to 1 */
emh203 0:3d9c67d97d6f 667 /* If lengths are not equal then zero pad has to be done to make the two
emh203 0:3d9c67d97d6f 668 * inputs of same length. But to improve the performance, we assume zeroes
emh203 0:3d9c67d97d6f 669 * in the output instead of zero padding either of the the inputs*/
emh203 0:3d9c67d97d6f 670 /* If srcALen > srcBLen, (srcALen - srcBLen) zeroes has to included in the
emh203 0:3d9c67d97d6f 671 * starting of the output buffer */
emh203 0:3d9c67d97d6f 672 /* If srcALen < srcBLen, (srcALen - srcBLen) zeroes has to included in the
emh203 0:3d9c67d97d6f 673 * ending of the output buffer */
emh203 0:3d9c67d97d6f 674 /* Once the zero padding is done the remaining of the output is calcualted
emh203 0:3d9c67d97d6f 675 * using convolution but with the shorter signal time shifted. */
emh203 0:3d9c67d97d6f 676
emh203 0:3d9c67d97d6f 677 /* Calculate the length of the remaining sequence */
emh203 0:3d9c67d97d6f 678 tot = ((srcALen + srcBLen) - 2u);
emh203 0:3d9c67d97d6f 679
emh203 0:3d9c67d97d6f 680 if(srcALen > srcBLen)
emh203 0:3d9c67d97d6f 681 {
emh203 0:3d9c67d97d6f 682 /* Calculating the number of zeros to be padded to the output */
emh203 0:3d9c67d97d6f 683 j = srcALen - srcBLen;
emh203 0:3d9c67d97d6f 684
emh203 0:3d9c67d97d6f 685 /* Initialise the pointer after zero padding */
emh203 0:3d9c67d97d6f 686 pDst += j;
emh203 0:3d9c67d97d6f 687 }
emh203 0:3d9c67d97d6f 688
emh203 0:3d9c67d97d6f 689 else if(srcALen < srcBLen)
emh203 0:3d9c67d97d6f 690 {
emh203 0:3d9c67d97d6f 691 /* Initialization to inputB pointer */
emh203 0:3d9c67d97d6f 692 pIn1 = pSrcB;
emh203 0:3d9c67d97d6f 693
emh203 0:3d9c67d97d6f 694 /* Initialization to the end of inputA pointer */
emh203 0:3d9c67d97d6f 695 pIn2 = pSrcA + (srcALen - 1u);
emh203 0:3d9c67d97d6f 696
emh203 0:3d9c67d97d6f 697 /* Initialisation of the pointer after zero padding */
emh203 0:3d9c67d97d6f 698 pDst = pDst + tot;
emh203 0:3d9c67d97d6f 699
emh203 0:3d9c67d97d6f 700 /* Swapping the lengths */
emh203 0:3d9c67d97d6f 701 j = srcALen;
emh203 0:3d9c67d97d6f 702 srcALen = srcBLen;
emh203 0:3d9c67d97d6f 703 srcBLen = j;
emh203 0:3d9c67d97d6f 704
emh203 0:3d9c67d97d6f 705 /* Setting the reverse flag */
emh203 0:3d9c67d97d6f 706 inv = 1;
emh203 0:3d9c67d97d6f 707
emh203 0:3d9c67d97d6f 708 }
emh203 0:3d9c67d97d6f 709
emh203 0:3d9c67d97d6f 710 /* Loop to calculate convolution for output length number of times */
emh203 0:3d9c67d97d6f 711 for (i = 0u; i <= tot; i++)
emh203 0:3d9c67d97d6f 712 {
emh203 0:3d9c67d97d6f 713 /* Initialize sum with zero to carry on MAC operations */
emh203 0:3d9c67d97d6f 714 sum = 0.0f;
emh203 0:3d9c67d97d6f 715
emh203 0:3d9c67d97d6f 716 /* Loop to perform MAC operations according to convolution equation */
emh203 0:3d9c67d97d6f 717 for (j = 0u; j <= i; j++)
emh203 0:3d9c67d97d6f 718 {
emh203 0:3d9c67d97d6f 719 /* Check the array limitations */
emh203 0:3d9c67d97d6f 720 if((((i - j) < srcBLen) && (j < srcALen)))
emh203 0:3d9c67d97d6f 721 {
emh203 0:3d9c67d97d6f 722 /* z[i] += x[i-j] * y[j] */
emh203 0:3d9c67d97d6f 723 sum += pIn1[j] * pIn2[-((int32_t) i - j)];
emh203 0:3d9c67d97d6f 724 }
emh203 0:3d9c67d97d6f 725 }
emh203 0:3d9c67d97d6f 726 /* Store the output in the destination buffer */
emh203 0:3d9c67d97d6f 727 if(inv == 1)
emh203 0:3d9c67d97d6f 728 *pDst-- = sum;
emh203 0:3d9c67d97d6f 729 else
emh203 0:3d9c67d97d6f 730 *pDst++ = sum;
emh203 0:3d9c67d97d6f 731 }
emh203 0:3d9c67d97d6f 732
emh203 0:3d9c67d97d6f 733 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emh203 0:3d9c67d97d6f 734
emh203 0:3d9c67d97d6f 735 }
emh203 0:3d9c67d97d6f 736
emh203 0:3d9c67d97d6f 737 /**
emh203 0:3d9c67d97d6f 738 * @} end of Corr group
emh203 0:3d9c67d97d6f 739 */