Diff: FilteringFunctions/arm_conv_partial_q31.c

Revision:

0:3d9c67d97d6f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FilteringFunctions/arm_conv_partial_q31.c	Mon Jul 28 15:03:15 2014 +0000
@@ -0,0 +1,607 @@
+/* ----------------------------------------------------------------------    
+* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
+*    
+* $Date:        12. March 2014
+* $Revision: 	V1.4.3
+*    
+* Project: 	    CMSIS DSP Library    
+* Title:		arm_conv_partial_q31.c    
+*    
+* Description:	Partial convolution of Q31 sequences.    
+*    
+* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
+*  
+* Redistribution and use in source and binary forms, with or without 
+* modification, are permitted provided that the following conditions
+* are met:
+*   - Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*   - Redistributions in binary form must reproduce the above copyright
+*     notice, this list of conditions and the following disclaimer in
+*     the documentation and/or other materials provided with the 
+*     distribution.
+*   - Neither the name of ARM LIMITED nor the names of its contributors
+*     may be used to endorse or promote products derived from this
+*     software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
+* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.  
+* -------------------------------------------------------------------- */
+
+#include "arm_math.h"
+
+/**    
+ * @ingroup groupFilters    
+ */
+
+/**    
+ * @addtogroup PartialConv    
+ * @{    
+ */
+
+/**    
+ * @brief Partial convolution of Q31 sequences.    
+ * @param[in]       *pSrcA points to the first input sequence.    
+ * @param[in]       srcALen length of the first input sequence.    
+ * @param[in]       *pSrcB points to the second input sequence.    
+ * @param[in]       srcBLen length of the second input sequence.    
+ * @param[out]      *pDst points to the location where the output result is written.    
+ * @param[in]       firstIndex is the first output sample to start with.    
+ * @param[in]       numPoints is the number of output points to be computed.    
+ * @return Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].    
+ *    
+ * See <code>arm_conv_partial_fast_q31()</code> for a faster but less precise implementation of this function for Cortex-M3 and Cortex-M4.    
+ */
+
+arm_status arm_conv_partial_q31(
+  q31_t * pSrcA,
+  uint32_t srcALen,
+  q31_t * pSrcB,
+  uint32_t srcBLen,
+  q31_t * pDst,
+  uint32_t firstIndex,
+  uint32_t numPoints)
+{
+
+
+#ifndef ARM_MATH_CM0_FAMILY
+
+  /* Run the below code for Cortex-M4 and Cortex-M3 */
+
+  q31_t *pIn1;                                   /* inputA pointer               */
+  q31_t *pIn2;                                   /* inputB pointer               */
+  q31_t *pOut = pDst;                            /* output pointer               */
+  q31_t *px;                                     /* Intermediate inputA pointer  */
+  q31_t *py;                                     /* Intermediate inputB pointer  */
+  q31_t *pSrc1, *pSrc2;                          /* Intermediate pointers        */
+  q63_t sum, acc0, acc1, acc2;                   /* Accumulator                  */
+  q31_t x0, x1, x2, c0;
+  uint32_t j, k, count, check, blkCnt;
+  int32_t blockSize1, blockSize2, blockSize3;    /* loop counter                 */
+  arm_status status;                             /* status of Partial convolution */
+
+
+  /* Check for range of output samples to be calculated */
+  if((firstIndex + numPoints) > ((srcALen + (srcBLen - 1u))))
+  {
+    /* Set status as ARM_MATH_ARGUMENT_ERROR */
+    status = ARM_MATH_ARGUMENT_ERROR;
+  }
+  else
+  {
+
+    /* The algorithm implementation is based on the lengths of the inputs. */
+    /* srcB is always made to slide across srcA. */
+    /* So srcBLen is always considered as shorter or equal to srcALen */
+    if(srcALen >= srcBLen)
+    {
+      /* Initialization of inputA pointer */
+      pIn1 = pSrcA;
+
+      /* Initialization of inputB pointer */
+      pIn2 = pSrcB;
+    }
+    else
+    {
+      /* Initialization of inputA pointer */
+      pIn1 = pSrcB;
+
+      /* Initialization of inputB pointer */
+      pIn2 = pSrcA;
+
+      /* srcBLen is always considered as shorter or equal to srcALen */
+      j = srcBLen;
+      srcBLen = srcALen;
+      srcALen = j;
+    }
+
+    /* Conditions to check which loopCounter holds    
+     * the first and last indices of the output samples to be calculated. */
+    check = firstIndex + numPoints;
+    blockSize3 = ((int32_t)check > (int32_t)srcALen) ? (int32_t)check - (int32_t)srcALen : 0;
+    blockSize3 = ((int32_t)firstIndex > (int32_t)srcALen - 1) ? blockSize3 - (int32_t)firstIndex + (int32_t)srcALen : blockSize3;
+    blockSize1 = (((int32_t) srcBLen - 1) - (int32_t) firstIndex);
+    blockSize1 = (blockSize1 > 0) ? ((check > (srcBLen - 1u)) ? blockSize1 :
+                                     (int32_t) numPoints) : 0;
+    blockSize2 = (int32_t) check - ((blockSize3 + blockSize1) +
+                                    (int32_t) firstIndex);
+    blockSize2 = (blockSize2 > 0) ? blockSize2 : 0;
+
+    /* conv(x,y) at n = x[n] * y[0] + x[n-1] * y[1] + x[n-2] * y[2] + ...+ x[n-N+1] * y[N -1] */
+    /* The function is internally    
+     * divided into three stages according to the number of multiplications that has to be    
+     * taken place between inputA samples and inputB samples. In the first stage of the    
+     * algorithm, the multiplications increase by one for every iteration.    
+     * In the second stage of the algorithm, srcBLen number of multiplications are done.    
+     * In the third stage of the algorithm, the multiplications decrease by one    
+     * for every iteration. */
+
+    /* Set the output pointer to point to the firstIndex    
+     * of the output sample to be calculated. */
+    pOut = pDst + firstIndex;
+
+    /* --------------------------    
+     * Initializations of stage1    
+     * -------------------------*/
+
+    /* sum = x[0] * y[0]    
+     * sum = x[0] * y[1] + x[1] * y[0]    
+     * ....    
+     * sum = x[0] * y[srcBlen - 1] + x[1] * y[srcBlen - 2] +...+ x[srcBLen - 1] * y[0]    
+     */
+
+    /* In this stage the MAC operations are increased by 1 for every iteration.    
+       The count variable holds the number of MAC operations performed.    
+       Since the partial convolution starts from firstIndex    
+       Number of Macs to be performed is firstIndex + 1 */
+    count = 1u + firstIndex;
+
+    /* Working pointer of inputA */
+    px = pIn1;
+
+    /* Working pointer of inputB */
+    pSrc2 = pIn2 + firstIndex;
+    py = pSrc2;
+
+    /* ------------------------    
+     * Stage1 process    
+     * ----------------------*/
+
+    /* The first loop starts here */
+    while(blockSize1 > 0)
+    {
+      /* Accumulator is made zero for every iteration */
+      sum = 0;
+
+      /* Apply loop unrolling and compute 4 MACs simultaneously. */
+      k = count >> 2u;
+
+      /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.    
+       ** a second loop below computes MACs for the remaining 1 to 3 samples. */
+      while(k > 0u)
+      {
+        /* x[0] * y[srcBLen - 1] */
+        sum += (q63_t) * px++ * (*py--);
+        /* x[1] * y[srcBLen - 2] */
+        sum += (q63_t) * px++ * (*py--);
+        /* x[2] * y[srcBLen - 3] */
+        sum += (q63_t) * px++ * (*py--);
+        /* x[3] * y[srcBLen - 4] */
+        sum += (q63_t) * px++ * (*py--);
+
+        /* Decrement the loop counter */
+        k--;
+      }
+
+      /* If the count is not a multiple of 4, compute any remaining MACs here.    
+       ** No loop unrolling is used. */
+      k = count % 0x4u;
+
+      while(k > 0u)
+      {
+        /* Perform the multiply-accumulate */
+        sum += (q63_t) * px++ * (*py--);
+
+        /* Decrement the loop counter */
+        k--;
+      }
+
+      /* Store the result in the accumulator in the destination buffer. */
+      *pOut++ = (q31_t) (sum >> 31);
+
+      /* Update the inputA and inputB pointers for next MAC calculation */
+      py = ++pSrc2;
+      px = pIn1;
+
+      /* Increment the MAC count */
+      count++;
+
+      /* Decrement the loop counter */
+      blockSize1--;
+    }
+
+    /* --------------------------    
+     * Initializations of stage2    
+     * ------------------------*/
+
+    /* sum = x[0] * y[srcBLen-1] + x[1] * y[srcBLen-2] +...+ x[srcBLen-1] * y[0]    
+     * sum = x[1] * y[srcBLen-1] + x[2] * y[srcBLen-2] +...+ x[srcBLen] * y[0]    
+     * ....    
+     * sum = x[srcALen-srcBLen-2] * y[srcBLen-1] + x[srcALen] * y[srcBLen-2] +...+ x[srcALen-1] * y[0]    
+     */
+
+    /* Working pointer of inputA */
+    if((int32_t)firstIndex - (int32_t)srcBLen + 1 > 0)
+    {
+      px = pIn1 + firstIndex - srcBLen + 1;
+    }
+    else
+    {
+      px = pIn1;
+    }
+
+    /* Working pointer of inputB */
+    pSrc2 = pIn2 + (srcBLen - 1u);
+    py = pSrc2;
+
+    /* count is index by which the pointer pIn1 to be incremented */
+    count = 0u;
+
+    /* -------------------    
+     * Stage2 process    
+     * ------------------*/
+
+    /* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed.    
+     * So, to loop unroll over blockSize2,    
+     * srcBLen should be greater than or equal to 4 */
+    if(srcBLen >= 4u)
+    {
+      /* Loop unroll over blkCnt */
+
+      blkCnt = blockSize2 / 3;
+      while(blkCnt > 0u)
+      {
+        /* Set all accumulators to zero */
+        acc0 = 0;
+        acc1 = 0;
+        acc2 = 0;
+
+        /* read x[0], x[1] samples */
+        x0 = *(px++);
+        x1 = *(px++);
+
+        /* Apply loop unrolling and compute 3 MACs simultaneously. */
+        k = srcBLen / 3;
+
+        /* First part of the processing with loop unrolling.  Compute 3 MACs at a time.        
+         ** a second loop below computes MACs for the remaining 1 to 2 samples. */
+        do
+        {
+          /* Read y[srcBLen - 1] sample */
+          c0 = *(py);
+
+          /* Read x[2] sample */
+          x2 = *(px);
+
+          /* Perform the multiply-accumulates */
+          /* acc0 +=  x[0] * y[srcBLen - 1] */
+          acc0 += (q63_t) x0 *c0;
+          /* acc1 +=  x[1] * y[srcBLen - 1] */
+          acc1 += (q63_t) x1 *c0;
+          /* acc2 +=  x[2] * y[srcBLen - 1] */
+          acc2 += (q63_t) x2 *c0;
+
+          /* Read y[srcBLen - 2] sample */
+          c0 = *(py - 1u);
+
+          /* Read x[3] sample */
+          x0 = *(px + 1u);
+
+          /* Perform the multiply-accumulate */
+          /* acc0 +=  x[1] * y[srcBLen - 2] */
+          acc0 += (q63_t) x1 *c0;
+          /* acc1 +=  x[2] * y[srcBLen - 2] */
+          acc1 += (q63_t) x2 *c0;
+          /* acc2 +=  x[3] * y[srcBLen - 2] */
+          acc2 += (q63_t) x0 *c0;
+
+          /* Read y[srcBLen - 3] sample */
+          c0 = *(py - 2u);
+
+          /* Read x[4] sample */
+          x1 = *(px + 2u);
+
+          /* Perform the multiply-accumulates */
+          /* acc0 +=  x[2] * y[srcBLen - 3] */
+          acc0 += (q63_t) x2 *c0;
+          /* acc1 +=  x[3] * y[srcBLen - 2] */
+          acc1 += (q63_t) x0 *c0;
+          /* acc2 +=  x[4] * y[srcBLen - 2] */
+          acc2 += (q63_t) x1 *c0;
+
+
+          px += 3u;
+
+          py -= 3u;
+
+        } while(--k);
+
+        /* If the srcBLen is not a multiple of 3, compute any remaining MACs here.        
+         ** No loop unrolling is used. */
+        k = srcBLen - (3 * (srcBLen / 3));
+
+        while(k > 0u)
+        {
+          /* Read y[srcBLen - 5] sample */
+          c0 = *(py--);
+
+          /* Read x[7] sample */
+          x2 = *(px++);
+
+          /* Perform the multiply-accumulates */
+          /* acc0 +=  x[4] * y[srcBLen - 5] */
+          acc0 += (q63_t) x0 *c0;
+          /* acc1 +=  x[5] * y[srcBLen - 5] */
+          acc1 += (q63_t) x1 *c0;
+          /* acc2 +=  x[6] * y[srcBLen - 5] */
+          acc2 += (q63_t) x2 *c0;
+
+          /* Reuse the present samples for the next MAC */
+          x0 = x1;
+          x1 = x2;
+
+          /* Decrement the loop counter */
+          k--;
+        }
+
+        /* Store the result in the accumulator in the destination buffer. */
+        *pOut++ = (q31_t) (acc0 >> 31);
+        *pOut++ = (q31_t) (acc1 >> 31);
+        *pOut++ = (q31_t) (acc2 >> 31);
+
+        /* Increment the pointer pIn1 index, count by 3 */
+        count += 3u;
+
+        /* Update the inputA and inputB pointers for next MAC calculation */
+        px = pIn1 + count;
+        py = pSrc2;
+
+        /* Decrement the loop counter */
+        blkCnt--;
+      }
+
+      /* If the blockSize2 is not a multiple of 3, compute any remaining output samples here.        
+       ** No loop unrolling is used. */
+      blkCnt = blockSize2 - 3 * (blockSize2 / 3);
+
+      while(blkCnt > 0u)
+      {
+        /* Accumulator is made zero for every iteration */
+        sum = 0;
+
+        /* Apply loop unrolling and compute 4 MACs simultaneously. */
+        k = srcBLen >> 2u;
+
+        /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.    
+         ** a second loop below computes MACs for the remaining 1 to 3 samples. */
+        while(k > 0u)
+        {
+          /* Perform the multiply-accumulates */
+          sum += (q63_t) * px++ * (*py--);
+          sum += (q63_t) * px++ * (*py--);
+          sum += (q63_t) * px++ * (*py--);
+          sum += (q63_t) * px++ * (*py--);
+
+          /* Decrement the loop counter */
+          k--;
+        }
+
+        /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.    
+         ** No loop unrolling is used. */
+        k = srcBLen % 0x4u;
+
+        while(k > 0u)
+        {
+          /* Perform the multiply-accumulate */
+          sum += (q63_t) * px++ * (*py--);
+
+          /* Decrement the loop counter */
+          k--;
+        }
+
+        /* Store the result in the accumulator in the destination buffer. */
+        *pOut++ = (q31_t) (sum >> 31);
+
+        /* Increment the MAC count */
+        count++;
+
+        /* Update the inputA and inputB pointers for next MAC calculation */
+        px = pIn1 + count;
+        py = pSrc2;
+
+        /* Decrement the loop counter */
+        blkCnt--;
+      }
+    }
+    else
+    {
+      /* If the srcBLen is not a multiple of 4,    
+       * the blockSize2 loop cannot be unrolled by 4 */
+      blkCnt = (uint32_t) blockSize2;
+
+      while(blkCnt > 0u)
+      {
+        /* Accumulator is made zero for every iteration */
+        sum = 0;
+
+        /* srcBLen number of MACS should be performed */
+        k = srcBLen;
+
+        while(k > 0u)
+        {
+          /* Perform the multiply-accumulate */
+          sum += (q63_t) * px++ * (*py--);
+
+          /* Decrement the loop counter */
+          k--;
+        }
+
+        /* Store the result in the accumulator in the destination buffer. */
+        *pOut++ = (q31_t) (sum >> 31);
+
+        /* Increment the MAC count */
+        count++;
+
+        /* Update the inputA and inputB pointers for next MAC calculation */
+        px = pIn1 + count;
+        py = pSrc2;
+
+        /* Decrement the loop counter */
+        blkCnt--;
+      }
+    }
+
+
+    /* --------------------------    
+     * Initializations of stage3    
+     * -------------------------*/
+
+    /* sum += x[srcALen-srcBLen+1] * y[srcBLen-1] + x[srcALen-srcBLen+2] * y[srcBLen-2] +...+ x[srcALen-1] * y[1]    
+     * sum += x[srcALen-srcBLen+2] * y[srcBLen-1] + x[srcALen-srcBLen+3] * y[srcBLen-2] +...+ x[srcALen-1] * y[2]    
+     * ....    
+     * sum +=  x[srcALen-2] * y[srcBLen-1] + x[srcALen-1] * y[srcBLen-2]    
+     * sum +=  x[srcALen-1] * y[srcBLen-1]    
+     */
+
+    /* In this stage the MAC operations are decreased by 1 for every iteration.    
+       The blockSize3 variable holds the number of MAC operations performed */
+    count = srcBLen - 1u;
+
+    /* Working pointer of inputA */
+    pSrc1 = (pIn1 + srcALen) - (srcBLen - 1u);
+    px = pSrc1;
+
+    /* Working pointer of inputB */
+    pSrc2 = pIn2 + (srcBLen - 1u);
+    py = pSrc2;
+
+    /* -------------------    
+     * Stage3 process    
+     * ------------------*/
+
+    while(blockSize3 > 0)
+    {
+      /* Accumulator is made zero for every iteration */
+      sum = 0;
+
+      /* Apply loop unrolling and compute 4 MACs simultaneously. */
+      k = count >> 2u;
+
+      /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.    
+       ** a second loop below computes MACs for the remaining 1 to 3 samples. */
+      while(k > 0u)
+      {
+        sum += (q63_t) * px++ * (*py--);
+        sum += (q63_t) * px++ * (*py--);
+        sum += (q63_t) * px++ * (*py--);
+        sum += (q63_t) * px++ * (*py--);
+
+        /* Decrement the loop counter */
+        k--;
+      }
+
+      /* If the blockSize3 is not a multiple of 4, compute any remaining MACs here.    
+       ** No loop unrolling is used. */
+      k = count % 0x4u;
+
+      while(k > 0u)
+      {
+        /* Perform the multiply-accumulate */
+        sum += (q63_t) * px++ * (*py--);
+
+        /* Decrement the loop counter */
+        k--;
+      }
+
+      /* Store the result in the accumulator in the destination buffer. */
+      *pOut++ = (q31_t) (sum >> 31);
+
+      /* Update the inputA and inputB pointers for next MAC calculation */
+      px = ++pSrc1;
+      py = pSrc2;
+
+      /* Decrement the MAC count */
+      count--;
+
+      /* Decrement the loop counter */
+      blockSize3--;
+
+    }
+
+    /* set status as ARM_MATH_SUCCESS */
+    status = ARM_MATH_SUCCESS;
+  }
+
+  /* Return to application */
+  return (status);
+
+#else
+
+  /* Run the below code for Cortex-M0 */
+
+  q31_t *pIn1 = pSrcA;                           /* inputA pointer */
+  q31_t *pIn2 = pSrcB;                           /* inputB pointer */
+  q63_t sum;                                     /* Accumulator */
+  uint32_t i, j;                                 /* loop counters */
+  arm_status status;                             /* status of Partial convolution */
+
+  /* Check for range of output samples to be calculated */
+  if((firstIndex + numPoints) > ((srcALen + (srcBLen - 1u))))
+  {
+    /* Set status as ARM_ARGUMENT_ERROR */
+    status = ARM_MATH_ARGUMENT_ERROR;
+  }
+  else
+  {
+    /* Loop to calculate convolution for output length number of values */
+    for (i = firstIndex; i <= (firstIndex + numPoints - 1); i++)
+    {
+      /* Initialize sum with zero to carry on MAC operations */
+      sum = 0;
+
+      /* Loop to perform MAC operations according to convolution equation */
+      for (j = 0; j <= i; j++)
+      {
+        /* Check the array limitations */
+        if(((i - j) < srcBLen) && (j < srcALen))
+        {
+          /* z[i] += x[i-j] * y[j] */
+          sum += ((q63_t) pIn1[j] * (pIn2[i - j]));
+        }
+      }
+
+      /* Store the output in the destination buffer */
+      pDst[i] = (q31_t) (sum >> 31u);
+    }
+    /* set status as ARM_SUCCESS as there are no argument errors */
+    status = ARM_MATH_SUCCESS;
+  }
+  return (status);
+
+#endif /*    #ifndef ARM_MATH_CM0_FAMILY      */
+
+}
+
+/**    
+ * @} end of PartialConv group    
+ */