CMSIS DSP library

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Fork of mbed-dsp by mbed official

Committer:
emilmont
Date:
Wed Nov 28 12:30:09 2012 +0000
Revision:
1:fdd22bb7aa52
Child:
2:da51fb522205
DSP library code

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emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
emilmont 1:fdd22bb7aa52 2 * Copyright (C) 2010 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
emilmont 1:fdd22bb7aa52 4 * $Date: 15. February 2012
emilmont 1:fdd22bb7aa52 5 * $Revision: V1.1.0
emilmont 1:fdd22bb7aa52 6 *
emilmont 1:fdd22bb7aa52 7 * Project: CMSIS DSP Library
emilmont 1:fdd22bb7aa52 8 * Title: arm_correlate_q7.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 1:fdd22bb7aa52 10 * Description: Correlation of Q7 sequences.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
emilmont 1:fdd22bb7aa52 14 * Version 1.1.0 2012/02/15
emilmont 1:fdd22bb7aa52 15 * Updated with more optimizations, bug fixes and minor API changes.
emilmont 1:fdd22bb7aa52 16 *
emilmont 1:fdd22bb7aa52 17 * Version 1.0.11 2011/10/18
emilmont 1:fdd22bb7aa52 18 * Bug Fix in conv, correlation, partial convolution.
emilmont 1:fdd22bb7aa52 19 *
emilmont 1:fdd22bb7aa52 20 * Version 1.0.10 2011/7/15
emilmont 1:fdd22bb7aa52 21 * Big Endian support added and Merged M0 and M3/M4 Source code.
emilmont 1:fdd22bb7aa52 22 *
emilmont 1:fdd22bb7aa52 23 * Version 1.0.3 2010/11/29
emilmont 1:fdd22bb7aa52 24 * Re-organized the CMSIS folders and updated documentation.
emilmont 1:fdd22bb7aa52 25 *
emilmont 1:fdd22bb7aa52 26 * Version 1.0.2 2010/11/11
emilmont 1:fdd22bb7aa52 27 * Documentation updated.
emilmont 1:fdd22bb7aa52 28 *
emilmont 1:fdd22bb7aa52 29 * Version 1.0.1 2010/10/05
emilmont 1:fdd22bb7aa52 30 * Production release and review comments incorporated.
emilmont 1:fdd22bb7aa52 31 *
emilmont 1:fdd22bb7aa52 32 * Version 1.0.0 2010/09/20
emilmont 1:fdd22bb7aa52 33 * Production release and review comments incorporated
emilmont 1:fdd22bb7aa52 34 *
emilmont 1:fdd22bb7aa52 35 * Version 0.0.7 2010/06/10
emilmont 1:fdd22bb7aa52 36 * Misra-C changes done
emilmont 1:fdd22bb7aa52 37 *
emilmont 1:fdd22bb7aa52 38 * -------------------------------------------------------------------- */
emilmont 1:fdd22bb7aa52 39
emilmont 1:fdd22bb7aa52 40 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 41
emilmont 1:fdd22bb7aa52 42 /**
emilmont 1:fdd22bb7aa52 43 * @ingroup groupFilters
emilmont 1:fdd22bb7aa52 44 */
emilmont 1:fdd22bb7aa52 45
emilmont 1:fdd22bb7aa52 46 /**
emilmont 1:fdd22bb7aa52 47 * @addtogroup Corr
emilmont 1:fdd22bb7aa52 48 * @{
emilmont 1:fdd22bb7aa52 49 */
emilmont 1:fdd22bb7aa52 50
emilmont 1:fdd22bb7aa52 51 /**
emilmont 1:fdd22bb7aa52 52 * @brief Correlation of Q7 sequences.
emilmont 1:fdd22bb7aa52 53 * @param[in] *pSrcA points to the first input sequence.
emilmont 1:fdd22bb7aa52 54 * @param[in] srcALen length of the first input sequence.
emilmont 1:fdd22bb7aa52 55 * @param[in] *pSrcB points to the second input sequence.
emilmont 1:fdd22bb7aa52 56 * @param[in] srcBLen length of the second input sequence.
emilmont 1:fdd22bb7aa52 57 * @param[out] *pDst points to the location where the output result is written. Length 2 * max(srcALen, srcBLen) - 1.
emilmont 1:fdd22bb7aa52 58 * @return none.
emilmont 1:fdd22bb7aa52 59 *
emilmont 1:fdd22bb7aa52 60 * @details
emilmont 1:fdd22bb7aa52 61 * <b>Scaling and Overflow Behavior:</b>
emilmont 1:fdd22bb7aa52 62 *
emilmont 1:fdd22bb7aa52 63 * \par
emilmont 1:fdd22bb7aa52 64 * The function is implemented using a 32-bit internal accumulator.
emilmont 1:fdd22bb7aa52 65 * Both the inputs are represented in 1.7 format and multiplications yield a 2.14 result.
emilmont 1:fdd22bb7aa52 66 * The 2.14 intermediate results are accumulated in a 32-bit accumulator in 18.14 format.
emilmont 1:fdd22bb7aa52 67 * This approach provides 17 guard bits and there is no risk of overflow as long as <code>max(srcALen, srcBLen)<131072</code>.
emilmont 1:fdd22bb7aa52 68 * The 18.14 result is then truncated to 18.7 format by discarding the low 7 bits and saturated to 1.7 format.
emilmont 1:fdd22bb7aa52 69 *
emilmont 1:fdd22bb7aa52 70 * \par
emilmont 1:fdd22bb7aa52 71 * Refer the function <code>arm_correlate_opt_q7()</code> for a faster implementation of this function.
emilmont 1:fdd22bb7aa52 72 *
emilmont 1:fdd22bb7aa52 73 */
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 void arm_correlate_q7(
emilmont 1:fdd22bb7aa52 76 q7_t * pSrcA,
emilmont 1:fdd22bb7aa52 77 uint32_t srcALen,
emilmont 1:fdd22bb7aa52 78 q7_t * pSrcB,
emilmont 1:fdd22bb7aa52 79 uint32_t srcBLen,
emilmont 1:fdd22bb7aa52 80 q7_t * pDst)
emilmont 1:fdd22bb7aa52 81 {
emilmont 1:fdd22bb7aa52 82
emilmont 1:fdd22bb7aa52 83
emilmont 1:fdd22bb7aa52 84 #ifndef ARM_MATH_CM0
emilmont 1:fdd22bb7aa52 85
emilmont 1:fdd22bb7aa52 86 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 87
emilmont 1:fdd22bb7aa52 88 q7_t *pIn1; /* inputA pointer */
emilmont 1:fdd22bb7aa52 89 q7_t *pIn2; /* inputB pointer */
emilmont 1:fdd22bb7aa52 90 q7_t *pOut = pDst; /* output pointer */
emilmont 1:fdd22bb7aa52 91 q7_t *px; /* Intermediate inputA pointer */
emilmont 1:fdd22bb7aa52 92 q7_t *py; /* Intermediate inputB pointer */
emilmont 1:fdd22bb7aa52 93 q7_t *pSrc1; /* Intermediate pointers */
emilmont 1:fdd22bb7aa52 94 q31_t sum, acc0, acc1, acc2, acc3; /* Accumulators */
emilmont 1:fdd22bb7aa52 95 q31_t input1, input2; /* temporary variables */
emilmont 1:fdd22bb7aa52 96 q15_t in1, in2; /* temporary variables */
emilmont 1:fdd22bb7aa52 97 q7_t x0, x1, x2, x3, c0, c1; /* temporary variables for holding input and coefficient values */
emilmont 1:fdd22bb7aa52 98 uint32_t j, k = 0u, count, blkCnt, outBlockSize, blockSize1, blockSize2, blockSize3; /* loop counter */
emilmont 1:fdd22bb7aa52 99 int32_t inc = 1;
emilmont 1:fdd22bb7aa52 100
emilmont 1:fdd22bb7aa52 101
emilmont 1:fdd22bb7aa52 102 /* The algorithm implementation is based on the lengths of the inputs. */
emilmont 1:fdd22bb7aa52 103 /* srcB is always made to slide across srcA. */
emilmont 1:fdd22bb7aa52 104 /* So srcBLen is always considered as shorter or equal to srcALen */
emilmont 1:fdd22bb7aa52 105 /* But CORR(x, y) is reverse of CORR(y, x) */
emilmont 1:fdd22bb7aa52 106 /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */
emilmont 1:fdd22bb7aa52 107 /* and the destination pointer modifier, inc is set to -1 */
emilmont 1:fdd22bb7aa52 108 /* If srcALen > srcBLen, zero pad has to be done to srcB to make the two inputs of same length */
emilmont 1:fdd22bb7aa52 109 /* But to improve the performance,
emilmont 1:fdd22bb7aa52 110 * we include zeroes in the output instead of zero padding either of the the inputs*/
emilmont 1:fdd22bb7aa52 111 /* If srcALen > srcBLen,
emilmont 1:fdd22bb7aa52 112 * (srcALen - srcBLen) zeroes has to included in the starting of the output buffer */
emilmont 1:fdd22bb7aa52 113 /* If srcALen < srcBLen,
emilmont 1:fdd22bb7aa52 114 * (srcALen - srcBLen) zeroes has to included in the ending of the output buffer */
emilmont 1:fdd22bb7aa52 115 if(srcALen >= srcBLen)
emilmont 1:fdd22bb7aa52 116 {
emilmont 1:fdd22bb7aa52 117 /* Initialization of inputA pointer */
emilmont 1:fdd22bb7aa52 118 pIn1 = (pSrcA);
emilmont 1:fdd22bb7aa52 119
emilmont 1:fdd22bb7aa52 120 /* Initialization of inputB pointer */
emilmont 1:fdd22bb7aa52 121 pIn2 = (pSrcB);
emilmont 1:fdd22bb7aa52 122
emilmont 1:fdd22bb7aa52 123 /* Number of output samples is calculated */
emilmont 1:fdd22bb7aa52 124 outBlockSize = (2u * srcALen) - 1u;
emilmont 1:fdd22bb7aa52 125
emilmont 1:fdd22bb7aa52 126 /* When srcALen > srcBLen, zero padding is done to srcB
emilmont 1:fdd22bb7aa52 127 * to make their lengths equal.
emilmont 1:fdd22bb7aa52 128 * Instead, (outBlockSize - (srcALen + srcBLen - 1))
emilmont 1:fdd22bb7aa52 129 * number of output samples are made zero */
emilmont 1:fdd22bb7aa52 130 j = outBlockSize - (srcALen + (srcBLen - 1u));
emilmont 1:fdd22bb7aa52 131
emilmont 1:fdd22bb7aa52 132 /* Updating the pointer position to non zero value */
emilmont 1:fdd22bb7aa52 133 pOut += j;
emilmont 1:fdd22bb7aa52 134
emilmont 1:fdd22bb7aa52 135 }
emilmont 1:fdd22bb7aa52 136 else
emilmont 1:fdd22bb7aa52 137 {
emilmont 1:fdd22bb7aa52 138 /* Initialization of inputA pointer */
emilmont 1:fdd22bb7aa52 139 pIn1 = (pSrcB);
emilmont 1:fdd22bb7aa52 140
emilmont 1:fdd22bb7aa52 141 /* Initialization of inputB pointer */
emilmont 1:fdd22bb7aa52 142 pIn2 = (pSrcA);
emilmont 1:fdd22bb7aa52 143
emilmont 1:fdd22bb7aa52 144 /* srcBLen is always considered as shorter or equal to srcALen */
emilmont 1:fdd22bb7aa52 145 j = srcBLen;
emilmont 1:fdd22bb7aa52 146 srcBLen = srcALen;
emilmont 1:fdd22bb7aa52 147 srcALen = j;
emilmont 1:fdd22bb7aa52 148
emilmont 1:fdd22bb7aa52 149 /* CORR(x, y) = Reverse order(CORR(y, x)) */
emilmont 1:fdd22bb7aa52 150 /* Hence set the destination pointer to point to the last output sample */
emilmont 1:fdd22bb7aa52 151 pOut = pDst + ((srcALen + srcBLen) - 2u);
emilmont 1:fdd22bb7aa52 152
emilmont 1:fdd22bb7aa52 153 /* Destination address modifier is set to -1 */
emilmont 1:fdd22bb7aa52 154 inc = -1;
emilmont 1:fdd22bb7aa52 155
emilmont 1:fdd22bb7aa52 156 }
emilmont 1:fdd22bb7aa52 157
emilmont 1:fdd22bb7aa52 158 /* The function is internally
emilmont 1:fdd22bb7aa52 159 * divided into three parts according to the number of multiplications that has to be
emilmont 1:fdd22bb7aa52 160 * taken place between inputA samples and inputB samples. In the first part of the
emilmont 1:fdd22bb7aa52 161 * algorithm, the multiplications increase by one for every iteration.
emilmont 1:fdd22bb7aa52 162 * In the second part of the algorithm, srcBLen number of multiplications are done.
emilmont 1:fdd22bb7aa52 163 * In the third part of the algorithm, the multiplications decrease by one
emilmont 1:fdd22bb7aa52 164 * for every iteration.*/
emilmont 1:fdd22bb7aa52 165 /* The algorithm is implemented in three stages.
emilmont 1:fdd22bb7aa52 166 * The loop counters of each stage is initiated here. */
emilmont 1:fdd22bb7aa52 167 blockSize1 = srcBLen - 1u;
emilmont 1:fdd22bb7aa52 168 blockSize2 = srcALen - (srcBLen - 1u);
emilmont 1:fdd22bb7aa52 169 blockSize3 = blockSize1;
emilmont 1:fdd22bb7aa52 170
emilmont 1:fdd22bb7aa52 171 /* --------------------------
emilmont 1:fdd22bb7aa52 172 * Initializations of stage1
emilmont 1:fdd22bb7aa52 173 * -------------------------*/
emilmont 1:fdd22bb7aa52 174
emilmont 1:fdd22bb7aa52 175 /* sum = x[0] * y[srcBlen - 1]
emilmont 1:fdd22bb7aa52 176 * sum = x[0] * y[srcBlen - 2] + x[1] * y[srcBlen - 1]
emilmont 1:fdd22bb7aa52 177 * ....
emilmont 1:fdd22bb7aa52 178 * sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen - 1] * y[srcBLen - 1]
emilmont 1:fdd22bb7aa52 179 */
emilmont 1:fdd22bb7aa52 180
emilmont 1:fdd22bb7aa52 181 /* In this stage the MAC operations are increased by 1 for every iteration.
emilmont 1:fdd22bb7aa52 182 The count variable holds the number of MAC operations performed */
emilmont 1:fdd22bb7aa52 183 count = 1u;
emilmont 1:fdd22bb7aa52 184
emilmont 1:fdd22bb7aa52 185 /* Working pointer of inputA */
emilmont 1:fdd22bb7aa52 186 px = pIn1;
emilmont 1:fdd22bb7aa52 187
emilmont 1:fdd22bb7aa52 188 /* Working pointer of inputB */
emilmont 1:fdd22bb7aa52 189 pSrc1 = pIn2 + (srcBLen - 1u);
emilmont 1:fdd22bb7aa52 190 py = pSrc1;
emilmont 1:fdd22bb7aa52 191
emilmont 1:fdd22bb7aa52 192 /* ------------------------
emilmont 1:fdd22bb7aa52 193 * Stage1 process
emilmont 1:fdd22bb7aa52 194 * ----------------------*/
emilmont 1:fdd22bb7aa52 195
emilmont 1:fdd22bb7aa52 196 /* The first stage starts here */
emilmont 1:fdd22bb7aa52 197 while(blockSize1 > 0u)
emilmont 1:fdd22bb7aa52 198 {
emilmont 1:fdd22bb7aa52 199 /* Accumulator is made zero for every iteration */
emilmont 1:fdd22bb7aa52 200 sum = 0;
emilmont 1:fdd22bb7aa52 201
emilmont 1:fdd22bb7aa52 202 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emilmont 1:fdd22bb7aa52 203 k = count >> 2;
emilmont 1:fdd22bb7aa52 204
emilmont 1:fdd22bb7aa52 205 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emilmont 1:fdd22bb7aa52 206 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 207 while(k > 0u)
emilmont 1:fdd22bb7aa52 208 {
emilmont 1:fdd22bb7aa52 209 /* x[0] , x[1] */
emilmont 1:fdd22bb7aa52 210 in1 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 211 in2 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 212 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 213
emilmont 1:fdd22bb7aa52 214 /* y[srcBLen - 4] , y[srcBLen - 3] */
emilmont 1:fdd22bb7aa52 215 in1 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 216 in2 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 217 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 218
emilmont 1:fdd22bb7aa52 219 /* x[0] * y[srcBLen - 4] */
emilmont 1:fdd22bb7aa52 220 /* x[1] * y[srcBLen - 3] */
emilmont 1:fdd22bb7aa52 221 sum = __SMLAD(input1, input2, sum);
emilmont 1:fdd22bb7aa52 222
emilmont 1:fdd22bb7aa52 223 /* x[2] , x[3] */
emilmont 1:fdd22bb7aa52 224 in1 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 225 in2 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 226 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 227
emilmont 1:fdd22bb7aa52 228 /* y[srcBLen - 2] , y[srcBLen - 1] */
emilmont 1:fdd22bb7aa52 229 in1 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 230 in2 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 231 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 232
emilmont 1:fdd22bb7aa52 233 /* x[2] * y[srcBLen - 2] */
emilmont 1:fdd22bb7aa52 234 /* x[3] * y[srcBLen - 1] */
emilmont 1:fdd22bb7aa52 235 sum = __SMLAD(input1, input2, sum);
emilmont 1:fdd22bb7aa52 236
emilmont 1:fdd22bb7aa52 237
emilmont 1:fdd22bb7aa52 238 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 239 k--;
emilmont 1:fdd22bb7aa52 240 }
emilmont 1:fdd22bb7aa52 241
emilmont 1:fdd22bb7aa52 242 /* If the count is not a multiple of 4, compute any remaining MACs here.
emilmont 1:fdd22bb7aa52 243 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 244 k = count % 0x4u;
emilmont 1:fdd22bb7aa52 245
emilmont 1:fdd22bb7aa52 246 while(k > 0u)
emilmont 1:fdd22bb7aa52 247 {
emilmont 1:fdd22bb7aa52 248 /* Perform the multiply-accumulates */
emilmont 1:fdd22bb7aa52 249 /* x[0] * y[srcBLen - 1] */
emilmont 1:fdd22bb7aa52 250 sum += (q31_t) ((q15_t) * px++ * *py++);
emilmont 1:fdd22bb7aa52 251
emilmont 1:fdd22bb7aa52 252 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 253 k--;
emilmont 1:fdd22bb7aa52 254 }
emilmont 1:fdd22bb7aa52 255
emilmont 1:fdd22bb7aa52 256 /* Store the result in the accumulator in the destination buffer. */
emilmont 1:fdd22bb7aa52 257 *pOut = (q7_t) (__SSAT(sum >> 7, 8));
emilmont 1:fdd22bb7aa52 258 /* Destination pointer is updated according to the address modifier, inc */
emilmont 1:fdd22bb7aa52 259 pOut += inc;
emilmont 1:fdd22bb7aa52 260
emilmont 1:fdd22bb7aa52 261 /* Update the inputA and inputB pointers for next MAC calculation */
emilmont 1:fdd22bb7aa52 262 py = pSrc1 - count;
emilmont 1:fdd22bb7aa52 263 px = pIn1;
emilmont 1:fdd22bb7aa52 264
emilmont 1:fdd22bb7aa52 265 /* Increment the MAC count */
emilmont 1:fdd22bb7aa52 266 count++;
emilmont 1:fdd22bb7aa52 267
emilmont 1:fdd22bb7aa52 268 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 269 blockSize1--;
emilmont 1:fdd22bb7aa52 270 }
emilmont 1:fdd22bb7aa52 271
emilmont 1:fdd22bb7aa52 272 /* --------------------------
emilmont 1:fdd22bb7aa52 273 * Initializations of stage2
emilmont 1:fdd22bb7aa52 274 * ------------------------*/
emilmont 1:fdd22bb7aa52 275
emilmont 1:fdd22bb7aa52 276 /* sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen-1] * y[srcBLen-1]
emilmont 1:fdd22bb7aa52 277 * sum = x[1] * y[0] + x[2] * y[1] +...+ x[srcBLen] * y[srcBLen-1]
emilmont 1:fdd22bb7aa52 278 * ....
emilmont 1:fdd22bb7aa52 279 * sum = x[srcALen-srcBLen-2] * y[0] + x[srcALen-srcBLen-1] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
emilmont 1:fdd22bb7aa52 280 */
emilmont 1:fdd22bb7aa52 281
emilmont 1:fdd22bb7aa52 282 /* Working pointer of inputA */
emilmont 1:fdd22bb7aa52 283 px = pIn1;
emilmont 1:fdd22bb7aa52 284
emilmont 1:fdd22bb7aa52 285 /* Working pointer of inputB */
emilmont 1:fdd22bb7aa52 286 py = pIn2;
emilmont 1:fdd22bb7aa52 287
emilmont 1:fdd22bb7aa52 288 /* count is index by which the pointer pIn1 to be incremented */
emilmont 1:fdd22bb7aa52 289 count = 0u;
emilmont 1:fdd22bb7aa52 290
emilmont 1:fdd22bb7aa52 291 /* -------------------
emilmont 1:fdd22bb7aa52 292 * Stage2 process
emilmont 1:fdd22bb7aa52 293 * ------------------*/
emilmont 1:fdd22bb7aa52 294
emilmont 1:fdd22bb7aa52 295 /* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed.
emilmont 1:fdd22bb7aa52 296 * So, to loop unroll over blockSize2,
emilmont 1:fdd22bb7aa52 297 * srcBLen should be greater than or equal to 4 */
emilmont 1:fdd22bb7aa52 298 if(srcBLen >= 4u)
emilmont 1:fdd22bb7aa52 299 {
emilmont 1:fdd22bb7aa52 300 /* Loop unroll over blockSize2, by 4 */
emilmont 1:fdd22bb7aa52 301 blkCnt = blockSize2 >> 2u;
emilmont 1:fdd22bb7aa52 302
emilmont 1:fdd22bb7aa52 303 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 304 {
emilmont 1:fdd22bb7aa52 305 /* Set all accumulators to zero */
emilmont 1:fdd22bb7aa52 306 acc0 = 0;
emilmont 1:fdd22bb7aa52 307 acc1 = 0;
emilmont 1:fdd22bb7aa52 308 acc2 = 0;
emilmont 1:fdd22bb7aa52 309 acc3 = 0;
emilmont 1:fdd22bb7aa52 310
emilmont 1:fdd22bb7aa52 311 /* read x[0], x[1], x[2] samples */
emilmont 1:fdd22bb7aa52 312 x0 = *px++;
emilmont 1:fdd22bb7aa52 313 x1 = *px++;
emilmont 1:fdd22bb7aa52 314 x2 = *px++;
emilmont 1:fdd22bb7aa52 315
emilmont 1:fdd22bb7aa52 316 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emilmont 1:fdd22bb7aa52 317 k = srcBLen >> 2u;
emilmont 1:fdd22bb7aa52 318
emilmont 1:fdd22bb7aa52 319 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emilmont 1:fdd22bb7aa52 320 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 321 do
emilmont 1:fdd22bb7aa52 322 {
emilmont 1:fdd22bb7aa52 323 /* Read y[0] sample */
emilmont 1:fdd22bb7aa52 324 c0 = *py++;
emilmont 1:fdd22bb7aa52 325 /* Read y[1] sample */
emilmont 1:fdd22bb7aa52 326 c1 = *py++;
emilmont 1:fdd22bb7aa52 327
emilmont 1:fdd22bb7aa52 328 /* Read x[3] sample */
emilmont 1:fdd22bb7aa52 329 x3 = *px++;
emilmont 1:fdd22bb7aa52 330
emilmont 1:fdd22bb7aa52 331 /* x[0] and x[1] are packed */
emilmont 1:fdd22bb7aa52 332 in1 = (q15_t) x0;
emilmont 1:fdd22bb7aa52 333 in2 = (q15_t) x1;
emilmont 1:fdd22bb7aa52 334
emilmont 1:fdd22bb7aa52 335 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 336
emilmont 1:fdd22bb7aa52 337 /* y[0] and y[1] are packed */
emilmont 1:fdd22bb7aa52 338 in1 = (q15_t) c0;
emilmont 1:fdd22bb7aa52 339 in2 = (q15_t) c1;
emilmont 1:fdd22bb7aa52 340
emilmont 1:fdd22bb7aa52 341 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 342
emilmont 1:fdd22bb7aa52 343 /* acc0 += x[0] * y[0] + x[1] * y[1] */
emilmont 1:fdd22bb7aa52 344 acc0 = __SMLAD(input1, input2, acc0);
emilmont 1:fdd22bb7aa52 345
emilmont 1:fdd22bb7aa52 346 /* x[1] and x[2] are packed */
emilmont 1:fdd22bb7aa52 347 in1 = (q15_t) x1;
emilmont 1:fdd22bb7aa52 348 in2 = (q15_t) x2;
emilmont 1:fdd22bb7aa52 349
emilmont 1:fdd22bb7aa52 350 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 351
emilmont 1:fdd22bb7aa52 352 /* acc1 += x[1] * y[0] + x[2] * y[1] */
emilmont 1:fdd22bb7aa52 353 acc1 = __SMLAD(input1, input2, acc1);
emilmont 1:fdd22bb7aa52 354
emilmont 1:fdd22bb7aa52 355 /* x[2] and x[3] are packed */
emilmont 1:fdd22bb7aa52 356 in1 = (q15_t) x2;
emilmont 1:fdd22bb7aa52 357 in2 = (q15_t) x3;
emilmont 1:fdd22bb7aa52 358
emilmont 1:fdd22bb7aa52 359 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 360
emilmont 1:fdd22bb7aa52 361 /* acc2 += x[2] * y[0] + x[3] * y[1] */
emilmont 1:fdd22bb7aa52 362 acc2 = __SMLAD(input1, input2, acc2);
emilmont 1:fdd22bb7aa52 363
emilmont 1:fdd22bb7aa52 364 /* Read x[4] sample */
emilmont 1:fdd22bb7aa52 365 x0 = *(px++);
emilmont 1:fdd22bb7aa52 366
emilmont 1:fdd22bb7aa52 367 /* x[3] and x[4] are packed */
emilmont 1:fdd22bb7aa52 368 in1 = (q15_t) x3;
emilmont 1:fdd22bb7aa52 369 in2 = (q15_t) x0;
emilmont 1:fdd22bb7aa52 370
emilmont 1:fdd22bb7aa52 371 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 372
emilmont 1:fdd22bb7aa52 373 /* acc3 += x[3] * y[0] + x[4] * y[1] */
emilmont 1:fdd22bb7aa52 374 acc3 = __SMLAD(input1, input2, acc3);
emilmont 1:fdd22bb7aa52 375
emilmont 1:fdd22bb7aa52 376 /* Read y[2] sample */
emilmont 1:fdd22bb7aa52 377 c0 = *py++;
emilmont 1:fdd22bb7aa52 378 /* Read y[3] sample */
emilmont 1:fdd22bb7aa52 379 c1 = *py++;
emilmont 1:fdd22bb7aa52 380
emilmont 1:fdd22bb7aa52 381 /* Read x[5] sample */
emilmont 1:fdd22bb7aa52 382 x1 = *px++;
emilmont 1:fdd22bb7aa52 383
emilmont 1:fdd22bb7aa52 384 /* x[2] and x[3] are packed */
emilmont 1:fdd22bb7aa52 385 in1 = (q15_t) x2;
emilmont 1:fdd22bb7aa52 386 in2 = (q15_t) x3;
emilmont 1:fdd22bb7aa52 387
emilmont 1:fdd22bb7aa52 388 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 389
emilmont 1:fdd22bb7aa52 390 /* y[2] and y[3] are packed */
emilmont 1:fdd22bb7aa52 391 in1 = (q15_t) c0;
emilmont 1:fdd22bb7aa52 392 in2 = (q15_t) c1;
emilmont 1:fdd22bb7aa52 393
emilmont 1:fdd22bb7aa52 394 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 395
emilmont 1:fdd22bb7aa52 396 /* acc0 += x[2] * y[2] + x[3] * y[3] */
emilmont 1:fdd22bb7aa52 397 acc0 = __SMLAD(input1, input2, acc0);
emilmont 1:fdd22bb7aa52 398
emilmont 1:fdd22bb7aa52 399 /* x[3] and x[4] are packed */
emilmont 1:fdd22bb7aa52 400 in1 = (q15_t) x3;
emilmont 1:fdd22bb7aa52 401 in2 = (q15_t) x0;
emilmont 1:fdd22bb7aa52 402
emilmont 1:fdd22bb7aa52 403 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 404
emilmont 1:fdd22bb7aa52 405 /* acc1 += x[3] * y[2] + x[4] * y[3] */
emilmont 1:fdd22bb7aa52 406 acc1 = __SMLAD(input1, input2, acc1);
emilmont 1:fdd22bb7aa52 407
emilmont 1:fdd22bb7aa52 408 /* x[4] and x[5] are packed */
emilmont 1:fdd22bb7aa52 409 in1 = (q15_t) x0;
emilmont 1:fdd22bb7aa52 410 in2 = (q15_t) x1;
emilmont 1:fdd22bb7aa52 411
emilmont 1:fdd22bb7aa52 412 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 413
emilmont 1:fdd22bb7aa52 414 /* acc2 += x[4] * y[2] + x[5] * y[3] */
emilmont 1:fdd22bb7aa52 415 acc2 = __SMLAD(input1, input2, acc2);
emilmont 1:fdd22bb7aa52 416
emilmont 1:fdd22bb7aa52 417 /* Read x[6] sample */
emilmont 1:fdd22bb7aa52 418 x2 = *px++;
emilmont 1:fdd22bb7aa52 419
emilmont 1:fdd22bb7aa52 420 /* x[5] and x[6] are packed */
emilmont 1:fdd22bb7aa52 421 in1 = (q15_t) x1;
emilmont 1:fdd22bb7aa52 422 in2 = (q15_t) x2;
emilmont 1:fdd22bb7aa52 423
emilmont 1:fdd22bb7aa52 424 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 425
emilmont 1:fdd22bb7aa52 426 /* acc3 += x[5] * y[2] + x[6] * y[3] */
emilmont 1:fdd22bb7aa52 427 acc3 = __SMLAD(input1, input2, acc3);
emilmont 1:fdd22bb7aa52 428
emilmont 1:fdd22bb7aa52 429 } while(--k);
emilmont 1:fdd22bb7aa52 430
emilmont 1:fdd22bb7aa52 431 /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
emilmont 1:fdd22bb7aa52 432 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 433 k = srcBLen % 0x4u;
emilmont 1:fdd22bb7aa52 434
emilmont 1:fdd22bb7aa52 435 while(k > 0u)
emilmont 1:fdd22bb7aa52 436 {
emilmont 1:fdd22bb7aa52 437 /* Read y[4] sample */
emilmont 1:fdd22bb7aa52 438 c0 = *py++;
emilmont 1:fdd22bb7aa52 439
emilmont 1:fdd22bb7aa52 440 /* Read x[7] sample */
emilmont 1:fdd22bb7aa52 441 x3 = *px++;
emilmont 1:fdd22bb7aa52 442
emilmont 1:fdd22bb7aa52 443 /* Perform the multiply-accumulates */
emilmont 1:fdd22bb7aa52 444 /* acc0 += x[4] * y[4] */
emilmont 1:fdd22bb7aa52 445 acc0 += ((q15_t) x0 * c0);
emilmont 1:fdd22bb7aa52 446 /* acc1 += x[5] * y[4] */
emilmont 1:fdd22bb7aa52 447 acc1 += ((q15_t) x1 * c0);
emilmont 1:fdd22bb7aa52 448 /* acc2 += x[6] * y[4] */
emilmont 1:fdd22bb7aa52 449 acc2 += ((q15_t) x2 * c0);
emilmont 1:fdd22bb7aa52 450 /* acc3 += x[7] * y[4] */
emilmont 1:fdd22bb7aa52 451 acc3 += ((q15_t) x3 * c0);
emilmont 1:fdd22bb7aa52 452
emilmont 1:fdd22bb7aa52 453 /* Reuse the present samples for the next MAC */
emilmont 1:fdd22bb7aa52 454 x0 = x1;
emilmont 1:fdd22bb7aa52 455 x1 = x2;
emilmont 1:fdd22bb7aa52 456 x2 = x3;
emilmont 1:fdd22bb7aa52 457
emilmont 1:fdd22bb7aa52 458 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 459 k--;
emilmont 1:fdd22bb7aa52 460 }
emilmont 1:fdd22bb7aa52 461
emilmont 1:fdd22bb7aa52 462 /* Store the result in the accumulator in the destination buffer. */
emilmont 1:fdd22bb7aa52 463 *pOut = (q7_t) (__SSAT(acc0 >> 7, 8));
emilmont 1:fdd22bb7aa52 464 /* Destination pointer is updated according to the address modifier, inc */
emilmont 1:fdd22bb7aa52 465 pOut += inc;
emilmont 1:fdd22bb7aa52 466
emilmont 1:fdd22bb7aa52 467 *pOut = (q7_t) (__SSAT(acc1 >> 7, 8));
emilmont 1:fdd22bb7aa52 468 pOut += inc;
emilmont 1:fdd22bb7aa52 469
emilmont 1:fdd22bb7aa52 470 *pOut = (q7_t) (__SSAT(acc2 >> 7, 8));
emilmont 1:fdd22bb7aa52 471 pOut += inc;
emilmont 1:fdd22bb7aa52 472
emilmont 1:fdd22bb7aa52 473 *pOut = (q7_t) (__SSAT(acc3 >> 7, 8));
emilmont 1:fdd22bb7aa52 474 pOut += inc;
emilmont 1:fdd22bb7aa52 475
emilmont 1:fdd22bb7aa52 476 count += 4u;
emilmont 1:fdd22bb7aa52 477 /* Update the inputA and inputB pointers for next MAC calculation */
emilmont 1:fdd22bb7aa52 478 px = pIn1 + count;
emilmont 1:fdd22bb7aa52 479 py = pIn2;
emilmont 1:fdd22bb7aa52 480
emilmont 1:fdd22bb7aa52 481 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 482 blkCnt--;
emilmont 1:fdd22bb7aa52 483 }
emilmont 1:fdd22bb7aa52 484
emilmont 1:fdd22bb7aa52 485 /* If the blockSize2 is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 486 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 487 blkCnt = blockSize2 % 0x4u;
emilmont 1:fdd22bb7aa52 488
emilmont 1:fdd22bb7aa52 489 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 490 {
emilmont 1:fdd22bb7aa52 491 /* Accumulator is made zero for every iteration */
emilmont 1:fdd22bb7aa52 492 sum = 0;
emilmont 1:fdd22bb7aa52 493
emilmont 1:fdd22bb7aa52 494 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emilmont 1:fdd22bb7aa52 495 k = srcBLen >> 2u;
emilmont 1:fdd22bb7aa52 496
emilmont 1:fdd22bb7aa52 497 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emilmont 1:fdd22bb7aa52 498 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 499 while(k > 0u)
emilmont 1:fdd22bb7aa52 500 {
emilmont 1:fdd22bb7aa52 501 /* Reading two inputs of SrcA buffer and packing */
emilmont 1:fdd22bb7aa52 502 in1 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 503 in2 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 504 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 505
emilmont 1:fdd22bb7aa52 506 /* Reading two inputs of SrcB buffer and packing */
emilmont 1:fdd22bb7aa52 507 in1 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 508 in2 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 509 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 510
emilmont 1:fdd22bb7aa52 511 /* Perform the multiply-accumulates */
emilmont 1:fdd22bb7aa52 512 sum = __SMLAD(input1, input2, sum);
emilmont 1:fdd22bb7aa52 513
emilmont 1:fdd22bb7aa52 514 /* Reading two inputs of SrcA buffer and packing */
emilmont 1:fdd22bb7aa52 515 in1 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 516 in2 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 517 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 518
emilmont 1:fdd22bb7aa52 519 /* Reading two inputs of SrcB buffer and packing */
emilmont 1:fdd22bb7aa52 520 in1 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 521 in2 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 522 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 523
emilmont 1:fdd22bb7aa52 524 /* Perform the multiply-accumulates */
emilmont 1:fdd22bb7aa52 525 sum = __SMLAD(input1, input2, sum);
emilmont 1:fdd22bb7aa52 526
emilmont 1:fdd22bb7aa52 527 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 528 k--;
emilmont 1:fdd22bb7aa52 529 }
emilmont 1:fdd22bb7aa52 530
emilmont 1:fdd22bb7aa52 531 /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
emilmont 1:fdd22bb7aa52 532 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 533 k = srcBLen % 0x4u;
emilmont 1:fdd22bb7aa52 534
emilmont 1:fdd22bb7aa52 535 while(k > 0u)
emilmont 1:fdd22bb7aa52 536 {
emilmont 1:fdd22bb7aa52 537 /* Perform the multiply-accumulates */
emilmont 1:fdd22bb7aa52 538 sum += ((q15_t) * px++ * *py++);
emilmont 1:fdd22bb7aa52 539
emilmont 1:fdd22bb7aa52 540 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 541 k--;
emilmont 1:fdd22bb7aa52 542 }
emilmont 1:fdd22bb7aa52 543
emilmont 1:fdd22bb7aa52 544 /* Store the result in the accumulator in the destination buffer. */
emilmont 1:fdd22bb7aa52 545 *pOut = (q7_t) (__SSAT(sum >> 7, 8));
emilmont 1:fdd22bb7aa52 546 /* Destination pointer is updated according to the address modifier, inc */
emilmont 1:fdd22bb7aa52 547 pOut += inc;
emilmont 1:fdd22bb7aa52 548
emilmont 1:fdd22bb7aa52 549 /* Increment the pointer pIn1 index, count by 1 */
emilmont 1:fdd22bb7aa52 550 count++;
emilmont 1:fdd22bb7aa52 551
emilmont 1:fdd22bb7aa52 552 /* Update the inputA and inputB pointers for next MAC calculation */
emilmont 1:fdd22bb7aa52 553 px = pIn1 + count;
emilmont 1:fdd22bb7aa52 554 py = pIn2;
emilmont 1:fdd22bb7aa52 555
emilmont 1:fdd22bb7aa52 556 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 557 blkCnt--;
emilmont 1:fdd22bb7aa52 558 }
emilmont 1:fdd22bb7aa52 559 }
emilmont 1:fdd22bb7aa52 560 else
emilmont 1:fdd22bb7aa52 561 {
emilmont 1:fdd22bb7aa52 562 /* If the srcBLen is not a multiple of 4,
emilmont 1:fdd22bb7aa52 563 * the blockSize2 loop cannot be unrolled by 4 */
emilmont 1:fdd22bb7aa52 564 blkCnt = blockSize2;
emilmont 1:fdd22bb7aa52 565
emilmont 1:fdd22bb7aa52 566 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 567 {
emilmont 1:fdd22bb7aa52 568 /* Accumulator is made zero for every iteration */
emilmont 1:fdd22bb7aa52 569 sum = 0;
emilmont 1:fdd22bb7aa52 570
emilmont 1:fdd22bb7aa52 571 /* Loop over srcBLen */
emilmont 1:fdd22bb7aa52 572 k = srcBLen;
emilmont 1:fdd22bb7aa52 573
emilmont 1:fdd22bb7aa52 574 while(k > 0u)
emilmont 1:fdd22bb7aa52 575 {
emilmont 1:fdd22bb7aa52 576 /* Perform the multiply-accumulate */
emilmont 1:fdd22bb7aa52 577 sum += ((q15_t) * px++ * *py++);
emilmont 1:fdd22bb7aa52 578
emilmont 1:fdd22bb7aa52 579 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 580 k--;
emilmont 1:fdd22bb7aa52 581 }
emilmont 1:fdd22bb7aa52 582
emilmont 1:fdd22bb7aa52 583 /* Store the result in the accumulator in the destination buffer. */
emilmont 1:fdd22bb7aa52 584 *pOut = (q7_t) (__SSAT(sum >> 7, 8));
emilmont 1:fdd22bb7aa52 585 /* Destination pointer is updated according to the address modifier, inc */
emilmont 1:fdd22bb7aa52 586 pOut += inc;
emilmont 1:fdd22bb7aa52 587
emilmont 1:fdd22bb7aa52 588 /* Increment the MAC count */
emilmont 1:fdd22bb7aa52 589 count++;
emilmont 1:fdd22bb7aa52 590
emilmont 1:fdd22bb7aa52 591 /* Update the inputA and inputB pointers for next MAC calculation */
emilmont 1:fdd22bb7aa52 592 px = pIn1 + count;
emilmont 1:fdd22bb7aa52 593 py = pIn2;
emilmont 1:fdd22bb7aa52 594
emilmont 1:fdd22bb7aa52 595
emilmont 1:fdd22bb7aa52 596 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 597 blkCnt--;
emilmont 1:fdd22bb7aa52 598 }
emilmont 1:fdd22bb7aa52 599 }
emilmont 1:fdd22bb7aa52 600
emilmont 1:fdd22bb7aa52 601 /* --------------------------
emilmont 1:fdd22bb7aa52 602 * Initializations of stage3
emilmont 1:fdd22bb7aa52 603 * -------------------------*/
emilmont 1:fdd22bb7aa52 604
emilmont 1:fdd22bb7aa52 605 /* sum += x[srcALen-srcBLen+1] * y[0] + x[srcALen-srcBLen+2] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
emilmont 1:fdd22bb7aa52 606 * sum += x[srcALen-srcBLen+2] * y[0] + x[srcALen-srcBLen+3] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
emilmont 1:fdd22bb7aa52 607 * ....
emilmont 1:fdd22bb7aa52 608 * sum += x[srcALen-2] * y[0] + x[srcALen-1] * y[1]
emilmont 1:fdd22bb7aa52 609 * sum += x[srcALen-1] * y[0]
emilmont 1:fdd22bb7aa52 610 */
emilmont 1:fdd22bb7aa52 611
emilmont 1:fdd22bb7aa52 612 /* In this stage the MAC operations are decreased by 1 for every iteration.
emilmont 1:fdd22bb7aa52 613 The count variable holds the number of MAC operations performed */
emilmont 1:fdd22bb7aa52 614 count = srcBLen - 1u;
emilmont 1:fdd22bb7aa52 615
emilmont 1:fdd22bb7aa52 616 /* Working pointer of inputA */
emilmont 1:fdd22bb7aa52 617 pSrc1 = pIn1 + (srcALen - (srcBLen - 1u));
emilmont 1:fdd22bb7aa52 618 px = pSrc1;
emilmont 1:fdd22bb7aa52 619
emilmont 1:fdd22bb7aa52 620 /* Working pointer of inputB */
emilmont 1:fdd22bb7aa52 621 py = pIn2;
emilmont 1:fdd22bb7aa52 622
emilmont 1:fdd22bb7aa52 623 /* -------------------
emilmont 1:fdd22bb7aa52 624 * Stage3 process
emilmont 1:fdd22bb7aa52 625 * ------------------*/
emilmont 1:fdd22bb7aa52 626
emilmont 1:fdd22bb7aa52 627 while(blockSize3 > 0u)
emilmont 1:fdd22bb7aa52 628 {
emilmont 1:fdd22bb7aa52 629 /* Accumulator is made zero for every iteration */
emilmont 1:fdd22bb7aa52 630 sum = 0;
emilmont 1:fdd22bb7aa52 631
emilmont 1:fdd22bb7aa52 632 /* Apply loop unrolling and compute 4 MACs simultaneously. */
emilmont 1:fdd22bb7aa52 633 k = count >> 2u;
emilmont 1:fdd22bb7aa52 634
emilmont 1:fdd22bb7aa52 635 /* First part of the processing with loop unrolling. Compute 4 MACs at a time.
emilmont 1:fdd22bb7aa52 636 ** a second loop below computes MACs for the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 637 while(k > 0u)
emilmont 1:fdd22bb7aa52 638 {
emilmont 1:fdd22bb7aa52 639 /* x[srcALen - srcBLen + 1] , x[srcALen - srcBLen + 2] */
emilmont 1:fdd22bb7aa52 640 in1 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 641 in2 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 642 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 643
emilmont 1:fdd22bb7aa52 644 /* y[0] , y[1] */
emilmont 1:fdd22bb7aa52 645 in1 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 646 in2 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 647 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 648
emilmont 1:fdd22bb7aa52 649 /* sum += x[srcALen - srcBLen + 1] * y[0] */
emilmont 1:fdd22bb7aa52 650 /* sum += x[srcALen - srcBLen + 2] * y[1] */
emilmont 1:fdd22bb7aa52 651 sum = __SMLAD(input1, input2, sum);
emilmont 1:fdd22bb7aa52 652
emilmont 1:fdd22bb7aa52 653 /* x[srcALen - srcBLen + 3] , x[srcALen - srcBLen + 4] */
emilmont 1:fdd22bb7aa52 654 in1 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 655 in2 = (q15_t) * px++;
emilmont 1:fdd22bb7aa52 656 input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 657
emilmont 1:fdd22bb7aa52 658 /* y[2] , y[3] */
emilmont 1:fdd22bb7aa52 659 in1 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 660 in2 = (q15_t) * py++;
emilmont 1:fdd22bb7aa52 661 input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
emilmont 1:fdd22bb7aa52 662
emilmont 1:fdd22bb7aa52 663 /* sum += x[srcALen - srcBLen + 3] * y[2] */
emilmont 1:fdd22bb7aa52 664 /* sum += x[srcALen - srcBLen + 4] * y[3] */
emilmont 1:fdd22bb7aa52 665 sum = __SMLAD(input1, input2, sum);
emilmont 1:fdd22bb7aa52 666
emilmont 1:fdd22bb7aa52 667 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 668 k--;
emilmont 1:fdd22bb7aa52 669 }
emilmont 1:fdd22bb7aa52 670
emilmont 1:fdd22bb7aa52 671 /* If the count is not a multiple of 4, compute any remaining MACs here.
emilmont 1:fdd22bb7aa52 672 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 673 k = count % 0x4u;
emilmont 1:fdd22bb7aa52 674
emilmont 1:fdd22bb7aa52 675 while(k > 0u)
emilmont 1:fdd22bb7aa52 676 {
emilmont 1:fdd22bb7aa52 677 /* Perform the multiply-accumulates */
emilmont 1:fdd22bb7aa52 678 sum += ((q15_t) * px++ * *py++);
emilmont 1:fdd22bb7aa52 679
emilmont 1:fdd22bb7aa52 680 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 681 k--;
emilmont 1:fdd22bb7aa52 682 }
emilmont 1:fdd22bb7aa52 683
emilmont 1:fdd22bb7aa52 684 /* Store the result in the accumulator in the destination buffer. */
emilmont 1:fdd22bb7aa52 685 *pOut = (q7_t) (__SSAT(sum >> 7, 8));
emilmont 1:fdd22bb7aa52 686 /* Destination pointer is updated according to the address modifier, inc */
emilmont 1:fdd22bb7aa52 687 pOut += inc;
emilmont 1:fdd22bb7aa52 688
emilmont 1:fdd22bb7aa52 689 /* Update the inputA and inputB pointers for next MAC calculation */
emilmont 1:fdd22bb7aa52 690 px = ++pSrc1;
emilmont 1:fdd22bb7aa52 691 py = pIn2;
emilmont 1:fdd22bb7aa52 692
emilmont 1:fdd22bb7aa52 693 /* Decrement the MAC count */
emilmont 1:fdd22bb7aa52 694 count--;
emilmont 1:fdd22bb7aa52 695
emilmont 1:fdd22bb7aa52 696 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 697 blockSize3--;
emilmont 1:fdd22bb7aa52 698 }
emilmont 1:fdd22bb7aa52 699
emilmont 1:fdd22bb7aa52 700 #else
emilmont 1:fdd22bb7aa52 701
emilmont 1:fdd22bb7aa52 702 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 703
emilmont 1:fdd22bb7aa52 704 q7_t *pIn1 = pSrcA; /* inputA pointer */
emilmont 1:fdd22bb7aa52 705 q7_t *pIn2 = pSrcB + (srcBLen - 1u); /* inputB pointer */
emilmont 1:fdd22bb7aa52 706 q31_t sum; /* Accumulator */
emilmont 1:fdd22bb7aa52 707 uint32_t i = 0u, j; /* loop counters */
emilmont 1:fdd22bb7aa52 708 uint32_t inv = 0u; /* Reverse order flag */
emilmont 1:fdd22bb7aa52 709 uint32_t tot = 0u; /* Length */
emilmont 1:fdd22bb7aa52 710
emilmont 1:fdd22bb7aa52 711 /* The algorithm implementation is based on the lengths of the inputs. */
emilmont 1:fdd22bb7aa52 712 /* srcB is always made to slide across srcA. */
emilmont 1:fdd22bb7aa52 713 /* So srcBLen is always considered as shorter or equal to srcALen */
emilmont 1:fdd22bb7aa52 714 /* But CORR(x, y) is reverse of CORR(y, x) */
emilmont 1:fdd22bb7aa52 715 /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */
emilmont 1:fdd22bb7aa52 716 /* and a varaible, inv is set to 1 */
emilmont 1:fdd22bb7aa52 717 /* If lengths are not equal then zero pad has to be done to make the two
emilmont 1:fdd22bb7aa52 718 * inputs of same length. But to improve the performance, we include zeroes
emilmont 1:fdd22bb7aa52 719 * in the output instead of zero padding either of the the inputs*/
emilmont 1:fdd22bb7aa52 720 /* If srcALen > srcBLen, (srcALen - srcBLen) zeroes has to included in the
emilmont 1:fdd22bb7aa52 721 * starting of the output buffer */
emilmont 1:fdd22bb7aa52 722 /* If srcALen < srcBLen, (srcALen - srcBLen) zeroes has to included in the
emilmont 1:fdd22bb7aa52 723 * ending of the output buffer */
emilmont 1:fdd22bb7aa52 724 /* Once the zero padding is done the remaining of the output is calcualted
emilmont 1:fdd22bb7aa52 725 * using convolution but with the shorter signal time shifted. */
emilmont 1:fdd22bb7aa52 726
emilmont 1:fdd22bb7aa52 727 /* Calculate the length of the remaining sequence */
emilmont 1:fdd22bb7aa52 728 tot = ((srcALen + srcBLen) - 2u);
emilmont 1:fdd22bb7aa52 729
emilmont 1:fdd22bb7aa52 730 if(srcALen > srcBLen)
emilmont 1:fdd22bb7aa52 731 {
emilmont 1:fdd22bb7aa52 732 /* Calculating the number of zeros to be padded to the output */
emilmont 1:fdd22bb7aa52 733 j = srcALen - srcBLen;
emilmont 1:fdd22bb7aa52 734
emilmont 1:fdd22bb7aa52 735 /* Initialise the pointer after zero padding */
emilmont 1:fdd22bb7aa52 736 pDst += j;
emilmont 1:fdd22bb7aa52 737 }
emilmont 1:fdd22bb7aa52 738
emilmont 1:fdd22bb7aa52 739 else if(srcALen < srcBLen)
emilmont 1:fdd22bb7aa52 740 {
emilmont 1:fdd22bb7aa52 741 /* Initialization to inputB pointer */
emilmont 1:fdd22bb7aa52 742 pIn1 = pSrcB;
emilmont 1:fdd22bb7aa52 743
emilmont 1:fdd22bb7aa52 744 /* Initialization to the end of inputA pointer */
emilmont 1:fdd22bb7aa52 745 pIn2 = pSrcA + (srcALen - 1u);
emilmont 1:fdd22bb7aa52 746
emilmont 1:fdd22bb7aa52 747 /* Initialisation of the pointer after zero padding */
emilmont 1:fdd22bb7aa52 748 pDst = pDst + tot;
emilmont 1:fdd22bb7aa52 749
emilmont 1:fdd22bb7aa52 750 /* Swapping the lengths */
emilmont 1:fdd22bb7aa52 751 j = srcALen;
emilmont 1:fdd22bb7aa52 752 srcALen = srcBLen;
emilmont 1:fdd22bb7aa52 753 srcBLen = j;
emilmont 1:fdd22bb7aa52 754
emilmont 1:fdd22bb7aa52 755 /* Setting the reverse flag */
emilmont 1:fdd22bb7aa52 756 inv = 1;
emilmont 1:fdd22bb7aa52 757
emilmont 1:fdd22bb7aa52 758 }
emilmont 1:fdd22bb7aa52 759
emilmont 1:fdd22bb7aa52 760 /* Loop to calculate convolution for output length number of times */
emilmont 1:fdd22bb7aa52 761 for (i = 0u; i <= tot; i++)
emilmont 1:fdd22bb7aa52 762 {
emilmont 1:fdd22bb7aa52 763 /* Initialize sum with zero to carry on MAC operations */
emilmont 1:fdd22bb7aa52 764 sum = 0;
emilmont 1:fdd22bb7aa52 765
emilmont 1:fdd22bb7aa52 766 /* Loop to perform MAC operations according to convolution equation */
emilmont 1:fdd22bb7aa52 767 for (j = 0u; j <= i; j++)
emilmont 1:fdd22bb7aa52 768 {
emilmont 1:fdd22bb7aa52 769 /* Check the array limitations */
emilmont 1:fdd22bb7aa52 770 if((((i - j) < srcBLen) && (j < srcALen)))
emilmont 1:fdd22bb7aa52 771 {
emilmont 1:fdd22bb7aa52 772 /* z[i] += x[i-j] * y[j] */
emilmont 1:fdd22bb7aa52 773 sum += ((q15_t) pIn1[j] * pIn2[-((int32_t) i - j)]);
emilmont 1:fdd22bb7aa52 774 }
emilmont 1:fdd22bb7aa52 775 }
emilmont 1:fdd22bb7aa52 776 /* Store the output in the destination buffer */
emilmont 1:fdd22bb7aa52 777 if(inv == 1)
emilmont 1:fdd22bb7aa52 778 *pDst-- = (q7_t) __SSAT((sum >> 7u), 8u);
emilmont 1:fdd22bb7aa52 779 else
emilmont 1:fdd22bb7aa52 780 *pDst++ = (q7_t) __SSAT((sum >> 7u), 8u);
emilmont 1:fdd22bb7aa52 781 }
emilmont 1:fdd22bb7aa52 782
emilmont 1:fdd22bb7aa52 783 #endif /* #ifndef ARM_MATH_CM0 */
emilmont 1:fdd22bb7aa52 784
emilmont 1:fdd22bb7aa52 785 }
emilmont 1:fdd22bb7aa52 786
emilmont 1:fdd22bb7aa52 787 /**
emilmont 1:fdd22bb7aa52 788 * @} end of Corr group
emilmont 1:fdd22bb7aa52 789 */