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# arm_correlate_q7.c

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    00001 /* ----------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        29. November 2010
    00005 * $Revision:    V1.0.3
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_correlate_q7.c
    00009 *
    00010 * Description:  Process function for Q7 Correlation.
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3
    00013 *
    00014 * Version 1.0.3 2010/11/29
    00015 *    Re-organized the CMSIS folders and updated documentation.
    00016 *
    00017 * Version 1.0.2 2010/11/11
    00018 *    Documentation updated.
    00019 *
    00020 * Version 1.0.1 2010/10/05
    00021 *    Production release and review comments incorporated.
    00022 *
    00023 * Version 1.0.0 2010/09/20
    00024 *    Production release and review comments incorporated
    00025 *
    00026 * Version 0.0.7  2010/06/10
    00027 *    Misra-C changes done
    00028 *
    00029 * -------------------------------------------------------------------- */
    00030
    00031 #include "arm_math.h"
    00032
    00062 void arm_correlate_q7(
    00063   q7_t * pSrcA,
    00064   uint32_t srcALen,
    00065   q7_t * pSrcB,
    00066   uint32_t srcBLen,
    00067   q7_t * pDst)
    00068 {
    00069   q7_t *pIn1;                                    /* inputA pointer               */
    00070   q7_t *pIn2;                                    /* inputB pointer               */
    00071   q7_t *pOut = pDst;                             /* output pointer               */
    00072   q7_t *px;                                      /* Intermediate inputA pointer  */
    00073   q7_t *py;                                      /* Intermediate inputB pointer  */
    00074   q7_t *pSrc1;                                   /* Intermediate pointers        */
    00075   q31_t sum, acc0, acc1, acc2, acc3;             /* Accumulators                  */
    00076   q31_t input1, input2;                          /* temporary variables */
    00077   q15_t in1, in2;                                /* temporary variables */
    00078   q7_t x0, x1, x2, x3, c0, c1;                   /* temporary variables for holding input and coefficient values */
    00079   uint32_t j, k = 0u, count, blkCnt, outBlockSize, blockSize1, blockSize2, blockSize3;  /* loop counter                 */
    00080   int32_t inc = 1;
    00081
    00082
    00083   /* The algorithm implementation is based on the lengths of the inputs. */
    00084   /* srcB is always made to slide across srcA. */
    00085   /* So srcBLen is always considered as shorter or equal to srcALen */
    00086   /* But CORR(x, y) is reverse of CORR(y, x) */
    00087   /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */
    00088   /* and the destination pointer modifier, inc is set to -1 */
    00089   /* If srcALen > srcBLen, zero pad has to be done to srcB to make the two inputs of same length */
    00090   /* But to improve the performance,
    00091    * we include zeroes in the output instead of zero padding either of the the inputs*/
    00092   /* If srcALen > srcBLen,
    00093    * (srcALen - srcBLen) zeroes has to included in the starting of the output buffer */
    00094   /* If srcALen < srcBLen,
    00095    * (srcALen - srcBLen) zeroes has to included in the ending of the output buffer */
    00096   if(srcALen >= srcBLen)
    00097   {
    00098     /* Initialization of inputA pointer */
    00099     pIn1 = (pSrcA);
    00100
    00101     /* Initialization of inputB pointer */
    00102     pIn2 = (pSrcB);
    00103
    00104     /* Number of output samples is calculated */
    00105     outBlockSize = (2u * srcALen) - 1u;
    00106
    00107     /* When srcALen > srcBLen, zero padding is done to srcB
    00108      * to make their lengths equal.
    00109      * Instead, (outBlockSize - (srcALen + srcBLen - 1))
    00110      * number of output samples are made zero */
    00111     j = outBlockSize - (srcALen + (srcBLen - 1u));
    00112
    00113     while(j > 0u)
    00114     {
    00115       /* Zero is stored in the destination buffer */
    00116       *pOut++ = 0;
    00117
    00118       /* Decrement the loop counter */
    00119       j--;
    00120     }
    00121
    00122   }
    00123   else
    00124   {
    00125     /* Initialization of inputA pointer */
    00126     pIn1 = (pSrcB);
    00127
    00128     /* Initialization of inputB pointer */
    00129     pIn2 = (pSrcA);
    00130
    00131     /* srcBLen is always considered as shorter or equal to srcALen */
    00132     j = srcBLen;
    00133     srcBLen = srcALen;
    00134     srcALen = j;
    00135
    00136     /* CORR(x, y) = Reverse order(CORR(y, x)) */
    00137     /* Hence set the destination pointer to point to the last output sample */
    00138     pOut = pDst + ((srcALen + srcBLen) - 2u);
    00139
    00140     /* Destination address modifier is set to -1 */
    00141     inc = -1;
    00142
    00143   }
    00144
    00145   /* The function is internally
    00146    * divided into three parts according to the number of multiplications that has to be
    00147    * taken place between inputA samples and inputB samples. In the first part of the
    00148    * algorithm, the multiplications increase by one for every iteration.
    00149    * In the second part of the algorithm, srcBLen number of multiplications are done.
    00150    * In the third part of the algorithm, the multiplications decrease by one
    00151    * for every iteration.*/
    00152   /* The algorithm is implemented in three stages.
    00153    * The loop counters of each stage is initiated here. */
    00154   blockSize1 = srcBLen - 1u;
    00155   blockSize2 = srcALen - (srcBLen - 1u);
    00156   blockSize3 = blockSize1;
    00157
    00158   /* --------------------------
    00159    * Initializations of stage1
    00160    * -------------------------*/
    00161
    00162   /* sum = x[0] * y[srcBlen - 1]
    00163    * sum = x[0] * y[srcBlen - 2] + x[1] * y[srcBlen - 1]
    00164    * ....
    00165    * sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen - 1] * y[srcBLen - 1]
    00166    */
    00167
    00168   /* In this stage the MAC operations are increased by 1 for every iteration.
    00169      The count variable holds the number of MAC operations performed */
    00170   count = 1u;
    00171
    00172   /* Working pointer of inputA */
    00173   px = pIn1;
    00174
    00175   /* Working pointer of inputB */
    00176   pSrc1 = pIn2 + (srcBLen - 1u);
    00177   py = pSrc1;
    00178
    00179   /* ------------------------
    00180    * Stage1 process
    00181    * ----------------------*/
    00182
    00183   /* The first stage starts here */
    00184   while(blockSize1 > 0u)
    00185   {
    00186     /* Accumulator is made zero for every iteration */
    00187     sum = 0;
    00188
    00189     /* Apply loop unrolling and compute 4 MACs simultaneously. */
    00190     k = count >> 2;
    00191
    00192     /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.
    00193      ** a second loop below computes MACs for the remaining 1 to 3 samples. */
    00194     while(k > 0u)
    00195     {
    00196       /* x[0] , x[1] */
    00197       in1 = (q15_t) * px++;
    00198       in2 = (q15_t) * px++;
    00199       input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00200
    00201       /* y[srcBLen - 4] , y[srcBLen - 3] */
    00202       in1 = (q15_t) * py++;
    00203       in2 = (q15_t) * py++;
    00204       input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00205
    00206       /* x[0] * y[srcBLen - 4] */
    00207       /* x[1] * y[srcBLen - 3] */
    00208       sum = __SMLAD(input1, input2, sum);
    00209
    00210       /* x[2] , x[3] */
    00211       in1 = (q15_t) * px++;
    00212       in2 = (q15_t) * px++;
    00213       input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00214
    00215       /* y[srcBLen - 2] , y[srcBLen - 1] */
    00216       in1 = (q15_t) * py++;
    00217       in2 = (q15_t) * py++;
    00218       input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00219
    00220       /* x[2] * y[srcBLen - 2] */
    00221       /* x[3] * y[srcBLen - 1] */
    00222       sum = __SMLAD(input1, input2, sum);
    00223
    00224
    00225       /* Decrement the loop counter */
    00226       k--;
    00227     }
    00228
    00229     /* If the count is not a multiple of 4, compute any remaining MACs here.
    00230      ** No loop unrolling is used. */
    00231     k = count % 0x4u;
    00232
    00233     while(k > 0u)
    00234     {
    00235       /* Perform the multiply-accumulates */
    00236       /* x[0] * y[srcBLen - 1] */
    00237       sum += (q31_t) ((q15_t) * px++ * *py++);
    00238
    00239       /* Decrement the loop counter */
    00240       k--;
    00241     }
    00242
    00243     /* Store the result in the accumulator in the destination buffer. */
    00244     *pOut = (q7_t) (__SSAT(sum >> 7, 8));
    00245     /* Destination pointer is updated according to the address modifier, inc */
    00246     pOut += inc;
    00247
    00248     /* Update the inputA and inputB pointers for next MAC calculation */
    00249     py = pSrc1 - count;
    00250     px = pIn1;
    00251
    00252     /* Increment the MAC count */
    00253     count++;
    00254
    00255     /* Decrement the loop counter */
    00256     blockSize1--;
    00257   }
    00258
    00259   /* --------------------------
    00260    * Initializations of stage2
    00261    * ------------------------*/
    00262
    00263   /* sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen-1] * y[srcBLen-1]
    00264    * sum = x[1] * y[0] + x[2] * y[1] +...+ x[srcBLen] * y[srcBLen-1]
    00265    * ....
    00266    * sum = x[srcALen-srcBLen-2] * y[0] + x[srcALen-srcBLen-1] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
    00267    */
    00268
    00269   /* Working pointer of inputA */
    00270   px = pIn1;
    00271
    00272   /* Working pointer of inputB */
    00273   py = pIn2;
    00274
    00275   /* count is index by which the pointer pIn1 to be incremented */
    00276   count = 1u;
    00277
    00278   /* -------------------
    00279    * Stage2 process
    00280    * ------------------*/
    00281
    00282   /* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed.
    00283    * So, to loop unroll over blockSize2,
    00284    * srcBLen should be greater than or equal to 4 */
    00285   if(srcBLen >= 4u)
    00286   {
    00287     /* Loop unroll over blockSize2, by 4 */
    00288     blkCnt = blockSize2 >> 2u;
    00289
    00290     while(blkCnt > 0u)
    00291     {
    00292       /* Set all accumulators to zero */
    00293       acc0 = 0;
    00294       acc1 = 0;
    00295       acc2 = 0;
    00296       acc3 = 0;
    00297
    00298       /* read x[0], x[1], x[2] samples */
    00299       x0 = *px++;
    00300       x1 = *px++;
    00301       x2 = *px++;
    00302
    00303       /* Apply loop unrolling and compute 4 MACs simultaneously. */
    00304       k = srcBLen >> 2u;
    00305
    00306       /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.
    00307        ** a second loop below computes MACs for the remaining 1 to 3 samples. */
    00308       do
    00309       {
    00310         /* Read y[0] sample */
    00311         c0 = *py++;
    00312         /* Read y[1] sample */
    00313         c1 = *py++;
    00314
    00315         /* Read x[3] sample */
    00316         x3 = *px++;
    00317
    00318         /* x[0] and x[1] are packed */
    00319         in1 = (q15_t) x0;
    00320         in2 = (q15_t) x1;
    00321
    00322         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00323
    00324         /* y[0] and y[1] are packed */
    00325         in1 = (q15_t) c0;
    00326         in2 = (q15_t) c1;
    00327
    00328         input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00329
    00330         /* acc0 += x[0] * y[0] + x[1] * y[1]  */
    00331         acc0 = __SMLAD(input1, input2, acc0);
    00332
    00333         /* x[1] and x[2] are packed */
    00334         in1 = (q15_t) x1;
    00335         in2 = (q15_t) x2;
    00336
    00337         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00338
    00339         /* acc1 += x[1] * y[0] + x[2] * y[1] */
    00340         acc1 = __SMLAD(input1, input2, acc1);
    00341
    00342         /* x[2] and x[3] are packed */
    00343         in1 = (q15_t) x2;
    00344         in2 = (q15_t) x3;
    00345
    00346         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00347
    00348         /* acc2 += x[2] * y[0] + x[3] * y[1]  */
    00349         acc2 = __SMLAD(input1, input2, acc2);
    00350
    00351         /* Read x[4] sample */
    00352         x0 = *(px++);
    00353
    00354         /* x[3] and x[4] are packed */
    00355         in1 = (q15_t) x3;
    00356         in2 = (q15_t) x0;
    00357
    00358         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00359
    00360         /* acc3 += x[3] * y[0] + x[4] * y[1]  */
    00361         acc3 = __SMLAD(input1, input2, acc3);
    00362
    00363         /* Read y[2] sample */
    00364         c0 = *py++;
    00365         /* Read y[3] sample */
    00366         c1 = *py++;
    00367
    00368         /* Read x[5] sample */
    00369         x1 = *px++;
    00370
    00371         /* x[2] and x[3] are packed */
    00372         in1 = (q15_t) x2;
    00373         in2 = (q15_t) x3;
    00374
    00375         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00376
    00377         /* y[2] and y[3] are packed */
    00378         in1 = (q15_t) c0;
    00379         in2 = (q15_t) c1;
    00380
    00381         input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00382
    00383         /* acc0 += x[2] * y[2] + x[3] * y[3]  */
    00384         acc0 = __SMLAD(input1, input2, acc0);
    00385
    00386         /* x[3] and x[4] are packed */
    00387         in1 = (q15_t) x3;
    00388         in2 = (q15_t) x0;
    00389
    00390         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00391
    00392         /* acc1 += x[3] * y[2] + x[4] * y[3]  */
    00393         acc1 = __SMLAD(input1, input2, acc1);
    00394
    00395         /* x[4] and x[5] are packed */
    00396         in1 = (q15_t) x0;
    00397         in2 = (q15_t) x1;
    00398
    00399         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00400
    00401         /* acc2 += x[4] * y[2] + x[5] * y[3]  */
    00402         acc2 = __SMLAD(input1, input2, acc2);
    00403
    00404         /* Read x[6] sample */
    00405         x2 = *px++;
    00406
    00407         /* x[5] and x[6] are packed */
    00408         in1 = (q15_t) x1;
    00409         in2 = (q15_t) x2;
    00410
    00411         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00412
    00413         /* acc3 += x[5] * y[2] + x[6] * y[3]  */
    00414         acc3 = __SMLAD(input1, input2, acc3);
    00415
    00416       } while(--k);
    00417
    00418       /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
    00419        ** No loop unrolling is used. */
    00420       k = srcBLen % 0x4u;
    00421
    00422       while(k > 0u)
    00423       {
    00424         /* Read y[4] sample */
    00425         c0 = *py++;
    00426
    00427         /* Read x[7] sample */
    00428         x3 = *px++;
    00429
    00430         /* Perform the multiply-accumulates */
    00431         /* acc0 +=  x[4] * y[4] */
    00432         acc0 += ((q15_t) x0 * c0);
    00433         /* acc1 +=  x[5] * y[4] */
    00434         acc1 += ((q15_t) x1 * c0);
    00435         /* acc2 +=  x[6] * y[4] */
    00436         acc2 += ((q15_t) x2 * c0);
    00437         /* acc3 +=  x[7] * y[4] */
    00438         acc3 += ((q15_t) x3 * c0);
    00439
    00440         /* Reuse the present samples for the next MAC */
    00441         x0 = x1;
    00442         x1 = x2;
    00443         x2 = x3;
    00444
    00445         /* Decrement the loop counter */
    00446         k--;
    00447       }
    00448
    00449       /* Store the result in the accumulator in the destination buffer. */
    00450       *pOut = (q7_t) (__SSAT(acc0 >> 7, 8));
    00451       /* Destination pointer is updated according to the address modifier, inc */
    00452       pOut += inc;
    00453
    00454       *pOut = (q7_t) (__SSAT(acc1 >> 7, 8));
    00455       pOut += inc;
    00456
    00457       *pOut = (q7_t) (__SSAT(acc2 >> 7, 8));
    00458       pOut += inc;
    00459
    00460       *pOut = (q7_t) (__SSAT(acc3 >> 7, 8));
    00461       pOut += inc;
    00462
    00463       /* Update the inputA and inputB pointers for next MAC calculation */
    00464       px = pIn1 + (count * 4u);
    00465       py = pIn2;
    00466
    00467       /* Increment the pointer pIn1 index, count by 1 */
    00468       count++;
    00469
    00470       /* Decrement the loop counter */
    00471       blkCnt--;
    00472     }
    00473
    00474     /* If the blockSize2 is not a multiple of 4, compute any remaining output samples here.
    00475      ** No loop unrolling is used. */
    00476     blkCnt = blockSize2 % 0x4u;
    00477
    00478     while(blkCnt > 0u)
    00479     {
    00480       /* Accumulator is made zero for every iteration */
    00481       sum = 0;
    00482
    00483       /* Apply loop unrolling and compute 4 MACs simultaneously. */
    00484       k = srcBLen >> 2u;
    00485
    00486       /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.
    00487        ** a second loop below computes MACs for the remaining 1 to 3 samples. */
    00488       while(k > 0u)
    00489       {
    00490         /* Reading two inputs of SrcA buffer and packing */
    00491         in1 = (q15_t) * px++;
    00492         in2 = (q15_t) * px++;
    00493         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00494
    00495         /* Reading two inputs of SrcB buffer and packing */
    00496         in1 = (q15_t) * py++;
    00497         in2 = (q15_t) * py++;
    00498         input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00499
    00500         /* Perform the multiply-accumulates */
    00501         sum = __SMLAD(input1, input2, sum);
    00502
    00503         /* Reading two inputs of SrcA buffer and packing */
    00504         in1 = (q15_t) * px++;
    00505         in2 = (q15_t) * px++;
    00506         input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00507
    00508         /* Reading two inputs of SrcB buffer and packing */
    00509         in1 = (q15_t) * py++;
    00510         in2 = (q15_t) * py++;
    00511         input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00512
    00513         /* Perform the multiply-accumulates */
    00514         sum = __SMLAD(input1, input2, sum);
    00515
    00516         /* Decrement the loop counter */
    00517         k--;
    00518       }
    00519
    00520       /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
    00521        ** No loop unrolling is used. */
    00522       k = srcBLen % 0x4u;
    00523
    00524       while(k > 0u)
    00525       {
    00526         /* Perform the multiply-accumulates */
    00527         sum += ((q15_t) * px++ * *py++);
    00528
    00529         /* Decrement the loop counter */
    00530         k--;
    00531       }
    00532
    00533       /* Store the result in the accumulator in the destination buffer. */
    00534       *pOut = (q7_t) (__SSAT(sum >> 7, 8));
    00535       /* Destination pointer is updated according to the address modifier, inc */
    00536       pOut += inc;
    00537
    00538       /* Update the inputA and inputB pointers for next MAC calculation */
    00539       px = pIn1 + count;
    00540       py = pIn2;
    00541
    00542       /* Increment the pointer pIn1 index, count by 1 */
    00543       count++;
    00544
    00545       /* Decrement the loop counter */
    00546       blkCnt--;
    00547     }
    00548   }
    00549   else
    00550   {
    00551     /* If the srcBLen is not a multiple of 4,
    00552      * the blockSize2 loop cannot be unrolled by 4 */
    00553     blkCnt = blockSize2;
    00554
    00555     while(blkCnt > 0u)
    00556     {
    00557       /* Accumulator is made zero for every iteration */
    00558       sum = 0;
    00559
    00560       /* Loop over srcBLen */
    00561       k = srcBLen;
    00562
    00563       while(k > 0u)
    00564       {
    00565         /* Perform the multiply-accumulate */
    00566         sum += ((q15_t) * px++ * *py++);
    00567
    00568         /* Decrement the loop counter */
    00569         k--;
    00570       }
    00571
    00572       /* Store the result in the accumulator in the destination buffer. */
    00573       *pOut = (q7_t) (__SSAT(sum >> 7, 8));
    00574       /* Destination pointer is updated according to the address modifier, inc */
    00575       pOut += inc;
    00576
    00577       /* Update the inputA and inputB pointers for next MAC calculation */
    00578       px = pIn1 + count;
    00579       py = pIn2;
    00580
    00581       /* Increment the MAC count */
    00582       count++;
    00583
    00584       /* Decrement the loop counter */
    00585       blkCnt--;
    00586     }
    00587   }
    00588
    00589   /* --------------------------
    00590    * Initializations of stage3
    00591    * -------------------------*/
    00592
    00593   /* sum += x[srcALen-srcBLen+1] * y[0] + x[srcALen-srcBLen+2] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
    00594    * sum += x[srcALen-srcBLen+2] * y[0] + x[srcALen-srcBLen+3] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
    00595    * ....
    00596    * sum +=  x[srcALen-2] * y[0] + x[srcALen-1] * y[1]
    00597    * sum +=  x[srcALen-1] * y[0]
    00598    */
    00599
    00600   /* In this stage the MAC operations are decreased by 1 for every iteration.
    00601      The count variable holds the number of MAC operations performed */
    00602   count = srcBLen - 1u;
    00603
    00604   /* Working pointer of inputA */
    00605   pSrc1 = pIn1 + (srcALen - (srcBLen - 1u));
    00606   px = pSrc1;
    00607
    00608   /* Working pointer of inputB */
    00609   py = pIn2;
    00610
    00611   /* -------------------
    00612    * Stage3 process
    00613    * ------------------*/
    00614
    00615   while(blockSize3 > 0u)
    00616   {
    00617     /* Accumulator is made zero for every iteration */
    00618     sum = 0;
    00619
    00620     /* Apply loop unrolling and compute 4 MACs simultaneously. */
    00621     k = count >> 2u;
    00622
    00623     /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.
    00624      ** a second loop below computes MACs for the remaining 1 to 3 samples. */
    00625     while(k > 0u)
    00626     {
    00627       /* x[srcALen - srcBLen + 1] , x[srcALen - srcBLen + 2]  */
    00628       in1 = (q15_t) * px++;
    00629       in2 = (q15_t) * px++;
    00630       input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00631
    00632       /* y[0] , y[1] */
    00633       in1 = (q15_t) * py++;
    00634       in2 = (q15_t) * py++;
    00635       input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00636
    00637       /* sum += x[srcALen - srcBLen + 1] * y[0] */
    00638       /* sum += x[srcALen - srcBLen + 2] * y[1] */
    00639       sum = __SMLAD(input1, input2, sum);
    00640
    00641       /* x[srcALen - srcBLen + 3] , x[srcALen - srcBLen + 4] */
    00642       in1 = (q15_t) * px++;
    00643       in2 = (q15_t) * px++;
    00644       input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00645
    00646       /* y[2] , y[3] */
    00647       in1 = (q15_t) * py++;
    00648       in2 = (q15_t) * py++;
    00649       input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00650
    00651       /* sum += x[srcALen - srcBLen + 3] * y[2] */
    00652       /* sum += x[srcALen - srcBLen + 4] * y[3] */
    00653       sum = __SMLAD(input1, input2, sum);
    00654
    00655       /* Decrement the loop counter */
    00656       k--;
    00657     }
    00658
    00659     /* If the count is not a multiple of 4, compute any remaining MACs here.
    00660      ** No loop unrolling is used. */
    00661     k = count % 0x4u;
    00662
    00663     while(k > 0u)
    00664     {
    00665       /* Perform the multiply-accumulates */
    00666       sum += ((q15_t) * px++ * *py++);
    00667
    00668       /* Decrement the loop counter */
    00669       k--;
    00670     }
    00671
    00672     /* Store the result in the accumulator in the destination buffer. */
    00673     *pOut = (q7_t) (__SSAT(sum >> 7, 8));
    00674     /* Destination pointer is updated according to the address modifier, inc */
    00675     pOut += inc;
    00676
    00677     /* Update the inputA and inputB pointers for next MAC calculation */
    00678     px = ++pSrc1;
    00679     py = pIn2;
    00680
    00681     /* Decrement the MAC count */
    00682     count--;
    00683
    00684     /* Decrement the loop counter */
    00685     blockSize3--;
    00686   }
    00687
    00688 }
    00689

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