diff options
Diffstat (limited to 'apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_fast_q31.c')
-rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_fast_q31.c | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_fast_q31.c b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_fast_q31.c new file mode 100644 index 000000000..628fd3ea5 --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_fast_q31.c @@ -0,0 +1,607 @@ +/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_correlate_fast_q31.c
+*
+* Description: Fast Q31 Correlation.
+*
+* Target Processor: Cortex-M4/Cortex-M3
+*
+* Version 1.1.0 2012/02/15
+* Updated with more optimizations, bug fixes and minor API changes.
+*
+* Version 1.0.11 2011/10/18
+* Bug Fix in conv, correlation, partial convolution.
+*
+* Version 1.0.10 2011/7/15
+* Big Endian support added and Merged M0 and M3/M4 Source code.
+*
+* Version 1.0.3 2010/11/29
+* Re-organized the CMSIS folders and updated documentation.
+*
+* Version 1.0.2 2010/11/11
+* Documentation updated.
+*
+* Version 1.0.1 2010/10/05
+* Production release and review comments incorporated.
+*
+* Version 1.0.0 2010/09/20
+* Production release and review comments incorporated.
+* -------------------------------------------------------------------- */
+
+#include "arm_math.h"
+
+/**
+ * @ingroup groupFilters
+ */
+
+/**
+ * @addtogroup Corr
+ * @{
+ */
+
+/**
+ * @brief Correlation of Q31 sequences (fast version) for Cortex-M3 and Cortex-M4.
+ * @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. Length 2 * max(srcALen, srcBLen) - 1.
+ * @return none.
+ *
+ * @details
+ * <b>Scaling and Overflow Behavior:</b>
+ *
+ * \par
+ * This function is optimized for speed at the expense of fixed-point precision and overflow protection.
+ * The result of each 1.31 x 1.31 multiplication is truncated to 2.30 format.
+ * These intermediate results are accumulated in a 32-bit register in 2.30 format.
+ * Finally, the accumulator is saturated and converted to a 1.31 result.
+ *
+ * \par
+ * The fast version has the same overflow behavior as the standard version but provides less precision since it discards the low 32 bits of each multiplication result.
+ * In order to avoid overflows completely the input signals must be scaled down.
+ * The input signals should be scaled down to avoid intermediate overflows.
+ * Scale down one of the inputs by 1/min(srcALen, srcBLen)to avoid overflows since a
+ * maximum of min(srcALen, srcBLen) number of additions is carried internally.
+ *
+ * \par
+ * See <code>arm_correlate_q31()</code> for a slower implementation of this function which uses 64-bit accumulation to provide higher precision.
+ */
+
+void arm_correlate_fast_q31(
+ q31_t * pSrcA,
+ uint32_t srcALen,
+ q31_t * pSrcB,
+ uint32_t srcBLen,
+ q31_t * pDst)
+{
+ 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; /* Intermediate pointers */
+ q31_t sum, acc0, acc1, acc2, acc3; /* Accumulators */
+ q31_t x0, x1, x2, x3, c0; /* temporary variables for holding input and coefficient values */
+ uint32_t j, k = 0u, count, blkCnt, outBlockSize, blockSize1, blockSize2, blockSize3; /* loop counter */
+ int32_t inc = 1; /* Destination address modifier */
+
+
+ /* 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);
+
+ /* Number of output samples is calculated */
+ outBlockSize = (2u * srcALen) - 1u;
+
+ /* When srcALen > srcBLen, zero padding is done to srcB
+ * to make their lengths equal.
+ * Instead, (outBlockSize - (srcALen + srcBLen - 1))
+ * number of output samples are made zero */
+ j = outBlockSize - (srcALen + (srcBLen - 1u));
+
+ /* Updating the pointer position to non zero value */
+ pOut += j;
+
+ }
+ 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;
+
+ /* CORR(x, y) = Reverse order(CORR(y, x)) */
+ /* Hence set the destination pointer to point to the last output sample */
+ pOut = pDst + ((srcALen + srcBLen) - 2u);
+
+ /* Destination address modifier is set to -1 */
+ inc = -1;
+
+ }
+
+ /* The function is internally
+ * divided into three parts according to the number of multiplications that has to be
+ * taken place between inputA samples and inputB samples. In the first part of the
+ * algorithm, the multiplications increase by one for every iteration.
+ * In the second part of the algorithm, srcBLen number of multiplications are done.
+ * In the third part of the algorithm, the multiplications decrease by one
+ * for every iteration.*/
+ /* The algorithm is implemented in three stages.
+ * The loop counters of each stage is initiated here. */
+ blockSize1 = srcBLen - 1u;
+ blockSize2 = srcALen - (srcBLen - 1u);
+ blockSize3 = blockSize1;
+
+ /* --------------------------
+ * Initializations of stage1
+ * -------------------------*/
+
+ /* sum = x[0] * y[srcBlen - 1]
+ * sum = x[0] * y[srcBlen - 2] + x[1] * y[srcBlen - 1]
+ * ....
+ * sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen - 1] * y[srcBLen - 1]
+ */
+
+ /* In this stage the MAC operations are increased by 1 for every iteration.
+ The count variable holds the number of MAC operations performed */
+ count = 1u;
+
+ /* Working pointer of inputA */
+ px = pIn1;
+
+ /* Working pointer of inputB */
+ pSrc1 = pIn2 + (srcBLen - 1u);
+ py = pSrc1;
+
+ /* ------------------------
+ * Stage1 process
+ * ----------------------*/
+
+ /* The first stage starts here */
+ while(blockSize1 > 0u)
+ {
+ /* Accumulator is made zero for every iteration */
+ sum = 0;
+
+ /* Apply loop unrolling and compute 4 MACs simultaneously. */
+ k = count >> 2;
+
+ /* 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 - 4] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ /* x[1] * y[srcBLen - 3] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ /* x[2] * y[srcBLen - 2] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ /* x[3] * y[srcBLen - 1] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+
+ /* 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-accumulates */
+ /* x[0] * y[srcBLen - 1] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+
+ /* Decrement the loop counter */
+ k--;
+ }
+
+ /* Store the result in the accumulator in the destination buffer. */
+ *pOut = sum << 1;
+ /* Destination pointer is updated according to the address modifier, inc */
+ pOut += inc;
+
+ /* Update the inputA and inputB pointers for next MAC calculation */
+ py = pSrc1 - count;
+ px = pIn1;
+
+ /* Increment the MAC count */
+ count++;
+
+ /* Decrement the loop counter */
+ blockSize1--;
+ }
+
+ /* --------------------------
+ * Initializations of stage2
+ * ------------------------*/
+
+ /* sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen-1] * y[srcBLen-1]
+ * sum = x[1] * y[0] + x[2] * y[1] +...+ x[srcBLen] * y[srcBLen-1]
+ * ....
+ * sum = x[srcALen-srcBLen-2] * y[0] + x[srcALen-srcBLen-1] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
+ */
+
+ /* Working pointer of inputA */
+ px = pIn1;
+
+ /* Working pointer of inputB */
+ py = pIn2;
+
+ /* 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 blockSize2, by 4 */
+ blkCnt = blockSize2 >> 2u;
+
+ while(blkCnt > 0u)
+ {
+ /* Set all accumulators to zero */
+ acc0 = 0;
+ acc1 = 0;
+ acc2 = 0;
+ acc3 = 0;
+
+ /* read x[0], x[1], x[2] samples */
+ x0 = *(px++);
+ x1 = *(px++);
+ x2 = *(px++);
+
+ /* 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. */
+ do
+ {
+ /* Read y[0] sample */
+ c0 = *(py++);
+
+ /* Read x[3] sample */
+ x3 = *(px++);
+
+ /* Perform the multiply-accumulate */
+ /* acc0 += x[0] * y[0] */
+ acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32);
+ /* acc1 += x[1] * y[0] */
+ acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32);
+ /* acc2 += x[2] * y[0] */
+ acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x2 * c0)) >> 32);
+ /* acc3 += x[3] * y[0] */
+ acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x3 * c0)) >> 32);
+
+ /* Read y[1] sample */
+ c0 = *(py++);
+
+ /* Read x[4] sample */
+ x0 = *(px++);
+
+ /* Perform the multiply-accumulates */
+ /* acc0 += x[1] * y[1] */
+ acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x1 * c0)) >> 32);
+ /* acc1 += x[2] * y[1] */
+ acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x2 * c0)) >> 32);
+ /* acc2 += x[3] * y[1] */
+ acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x3 * c0)) >> 32);
+ /* acc3 += x[4] * y[1] */
+ acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x0 * c0)) >> 32);
+
+ /* Read y[2] sample */
+ c0 = *(py++);
+
+ /* Read x[5] sample */
+ x1 = *(px++);
+
+ /* Perform the multiply-accumulates */
+ /* acc0 += x[2] * y[2] */
+ acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x2 * c0)) >> 32);
+ /* acc1 += x[3] * y[2] */
+ acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x3 * c0)) >> 32);
+ /* acc2 += x[4] * y[2] */
+ acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x0 * c0)) >> 32);
+ /* acc3 += x[5] * y[2] */
+ acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x1 * c0)) >> 32);
+
+ /* Read y[3] sample */
+ c0 = *(py++);
+
+ /* Read x[6] sample */
+ x2 = *(px++);
+
+ /* Perform the multiply-accumulates */
+ /* acc0 += x[3] * y[3] */
+ acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x3 * c0)) >> 32);
+ /* acc1 += x[4] * y[3] */
+ acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x0 * c0)) >> 32);
+ /* acc2 += x[5] * y[3] */
+ acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x1 * c0)) >> 32);
+ /* acc3 += x[6] * y[3] */
+ acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x2 * c0)) >> 32);
+
+
+ } while(--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)
+ {
+ /* Read y[4] sample */
+ c0 = *(py++);
+
+ /* Read x[7] sample */
+ x3 = *(px++);
+
+ /* Perform the multiply-accumulates */
+ /* acc0 += x[4] * y[4] */
+ acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32);
+ /* acc1 += x[5] * y[4] */
+ acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32);
+ /* acc2 += x[6] * y[4] */
+ acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x2 * c0)) >> 32);
+ /* acc3 += x[7] * y[4] */
+ acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x3 * c0)) >> 32);
+
+ /* Reuse the present samples for the next MAC */
+ x0 = x1;
+ x1 = x2;
+ x2 = x3;
+
+ /* Decrement the loop counter */
+ k--;
+ }
+
+ /* Store the result in the accumulator in the destination buffer. */
+ *pOut = (q31_t) (acc0 << 1);
+ /* Destination pointer is updated according to the address modifier, inc */
+ pOut += inc;
+
+ *pOut = (q31_t) (acc1 << 1);
+ pOut += inc;
+
+ *pOut = (q31_t) (acc2 << 1);
+ pOut += inc;
+
+ *pOut = (q31_t) (acc3 << 1);
+ pOut += inc;
+
+ /* Increment the pointer pIn1 index, count by 4 */
+ count += 4u;
+
+ /* Update the inputA and inputB pointers for next MAC calculation */
+ px = pIn1 + count;
+ py = pIn2;
+
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* If the blockSize2 is not a multiple of 4, compute any remaining output samples here.
+ ** No loop unrolling is used. */
+ blkCnt = blockSize2 % 0x4u;
+
+ 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 = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+
+ /* 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 = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+
+ /* Decrement the loop counter */
+ k--;
+ }
+
+ /* Store the result in the accumulator in the destination buffer. */
+ *pOut = sum << 1;
+ /* Destination pointer is updated according to the address modifier, inc */
+ pOut += inc;
+
+ /* Increment the MAC count */
+ count++;
+
+ /* Update the inputA and inputB pointers for next MAC calculation */
+ px = pIn1 + count;
+ py = pIn2;
+
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+ }
+ else
+ {
+ /* If the srcBLen is not a multiple of 4,
+ * the blockSize2 loop cannot be unrolled by 4 */
+ blkCnt = blockSize2;
+
+ while(blkCnt > 0u)
+ {
+ /* Accumulator is made zero for every iteration */
+ sum = 0;
+
+ /* Loop over srcBLen */
+ k = srcBLen;
+
+ while(k > 0u)
+ {
+ /* Perform the multiply-accumulate */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+
+ /* Decrement the loop counter */
+ k--;
+ }
+
+ /* Store the result in the accumulator in the destination buffer. */
+ *pOut = sum << 1;
+ /* Destination pointer is updated according to the address modifier, inc */
+ pOut += inc;
+
+ /* Increment the MAC count */
+ count++;
+
+ /* Update the inputA and inputB pointers for next MAC calculation */
+ px = pIn1 + count;
+ py = pIn2;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+ }
+
+ /* --------------------------
+ * Initializations of stage3
+ * -------------------------*/
+
+ /* sum += x[srcALen-srcBLen+1] * y[0] + x[srcALen-srcBLen+2] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
+ * sum += x[srcALen-srcBLen+2] * y[0] + x[srcALen-srcBLen+3] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
+ * ....
+ * sum += x[srcALen-2] * y[0] + x[srcALen-1] * y[1]
+ * sum += x[srcALen-1] * y[0]
+ */
+
+ /* In this stage the MAC operations are decreased by 1 for every iteration.
+ The count 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 */
+ py = pIn2;
+
+ /* -------------------
+ * Stage3 process
+ * ------------------*/
+
+ while(blockSize3 > 0u)
+ {
+ /* 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)
+ {
+ /* Perform the multiply-accumulates */
+ /* sum += x[srcALen - srcBLen + 4] * y[3] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ /* sum += x[srcALen - srcBLen + 3] * y[2] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ /* sum += x[srcALen - srcBLen + 2] * y[1] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+ /* sum += x[srcALen - srcBLen + 1] * y[0] */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+
+ /* 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-accumulates */
+ sum = (q31_t) ((((q63_t) sum << 32) +
+ ((q63_t) * px++ * (*py++))) >> 32);
+
+ /* Decrement the loop counter */
+ k--;
+ }
+
+ /* Store the result in the accumulator in the destination buffer. */
+ *pOut = sum << 1;
+ /* Destination pointer is updated according to the address modifier, inc */
+ pOut += inc;
+
+ /* Update the inputA and inputB pointers for next MAC calculation */
+ px = ++pSrc1;
+ py = pIn2;
+
+ /* Decrement the MAC count */
+ count--;
+
+ /* Decrement the loop counter */
+ blockSize3--;
+ }
+
+}
+
+/**
+ * @} end of Corr group
+ */
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