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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_fir_f32.c')
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diff --git a/DSP_Lib/Source/FilteringFunctions/arm_fir_f32.c b/DSP_Lib/Source/FilteringFunctions/arm_fir_f32.c new file mode 100644 index 0000000..a827e68 --- /dev/null +++ b/DSP_Lib/Source/FilteringFunctions/arm_fir_f32.c @@ -0,0 +1,997 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 19. March 2015 +* $Revision: V.1.4.5 +* +* Project: CMSIS DSP Library +* Title: arm_fir_f32.c +* +* Description: Floating-point FIR filter processing function. +* +* 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 +*/ + +/** +* @defgroup FIR Finite Impulse Response (FIR) Filters +* +* This set of functions implements Finite Impulse Response (FIR) filters +* for Q7, Q15, Q31, and floating-point data types. Fast versions of Q15 and Q31 are also provided. +* The functions operate on blocks of input and output data and each call to the function processes +* <code>blockSize</code> samples through the filter. <code>pSrc</code> and +* <code>pDst</code> points to input and output arrays containing <code>blockSize</code> values. +* +* \par Algorithm: +* The FIR filter algorithm is based upon a sequence of multiply-accumulate (MAC) operations. +* Each filter coefficient <code>b[n]</code> is multiplied by a state variable which equals a previous input sample <code>x[n]</code>. +* <pre> +* y[n] = b[0] * x[n] + b[1] * x[n-1] + b[2] * x[n-2] + ...+ b[numTaps-1] * x[n-numTaps+1] +* </pre> +* \par +* \image html FIR.gif "Finite Impulse Response filter" +* \par +* <code>pCoeffs</code> points to a coefficient array of size <code>numTaps</code>. +* Coefficients are stored in time reversed order. +* \par +* <pre> +* {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]} +* </pre> +* \par +* <code>pState</code> points to a state array of size <code>numTaps + blockSize - 1</code>. +* Samples in the state buffer are stored in the following order. +* \par +* <pre> +* {x[n-numTaps+1], x[n-numTaps], x[n-numTaps-1], x[n-numTaps-2]....x[0], x[1], ..., x[blockSize-1]} +* </pre> +* \par +* Note that the length of the state buffer exceeds the length of the coefficient array by <code>blockSize-1</code>. +* The increased state buffer length allows circular addressing, which is traditionally used in the FIR filters, +* to be avoided and yields a significant speed improvement. +* The state variables are updated after each block of data is processed; the coefficients are untouched. +* \par Instance Structure +* The coefficients and state variables for a filter are stored together in an instance data structure. +* A separate instance structure must be defined for each filter. +* Coefficient arrays may be shared among several instances while state variable arrays cannot be shared. +* There are separate instance structure declarations for each of the 4 supported data types. +* +* \par Initialization Functions +* There is also an associated initialization function for each data type. +* The initialization function performs the following operations: +* - Sets the values of the internal structure fields. +* - Zeros out the values in the state buffer. +* To do this manually without calling the init function, assign the follow subfields of the instance structure: +* numTaps, pCoeffs, pState. Also set all of the values in pState to zero. +* +* \par +* Use of the initialization function is optional. +* However, if the initialization function is used, then the instance structure cannot be placed into a const data section. +* To place an instance structure into a const data section, the instance structure must be manually initialized. +* Set the values in the state buffer to zeros before static initialization. +* The code below statically initializes each of the 4 different data type filter instance structures +* <pre> +*arm_fir_instance_f32 S = {numTaps, pState, pCoeffs}; +*arm_fir_instance_q31 S = {numTaps, pState, pCoeffs}; +*arm_fir_instance_q15 S = {numTaps, pState, pCoeffs}; +*arm_fir_instance_q7 S = {numTaps, pState, pCoeffs}; +* </pre> +* +* where <code>numTaps</code> is the number of filter coefficients in the filter; <code>pState</code> is the address of the state buffer; +* <code>pCoeffs</code> is the address of the coefficient buffer. +* +* \par Fixed-Point Behavior +* Care must be taken when using the fixed-point versions of the FIR filter functions. +* In particular, the overflow and saturation behavior of the accumulator used in each function must be considered. +* Refer to the function specific documentation below for usage guidelines. +*/ + +/** +* @addtogroup FIR +* @{ +*/ + +/** +* +* @param[in] *S points to an instance of the floating-point FIR filter structure. +* @param[in] *pSrc points to the block of input data. +* @param[out] *pDst points to the block of output data. +* @param[in] blockSize number of samples to process per call. +* @return none. +* +*/ + +#if defined(ARM_MATH_CM7) + +void arm_fir_f32( +const arm_fir_instance_f32 * S, +float32_t * pSrc, +float32_t * pDst, +uint32_t blockSize) +{ + float32_t *pState = S->pState; /* State pointer */ + float32_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + float32_t *pStateCurnt; /* Points to the current sample of the state */ + float32_t *px, *pb; /* Temporary pointers for state and coefficient buffers */ + float32_t acc0, acc1, acc2, acc3, acc4, acc5, acc6, acc7; /* Accumulators */ + float32_t x0, x1, x2, x3, x4, x5, x6, x7, c0; /* Temporary variables to hold state and coefficient values */ + uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ + uint32_t i, tapCnt, blkCnt; /* Loop counters */ + + /* S->pState points to state array which contains previous frame (numTaps - 1) samples */ + /* pStateCurnt points to the location where the new input data should be written */ + pStateCurnt = &(S->pState[(numTaps - 1u)]); + + /* Apply loop unrolling and compute 8 output values simultaneously. + * The variables acc0 ... acc7 hold output values that are being computed: + * + * acc0 = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] + * acc1 = b[numTaps-1] * x[n-numTaps] + b[numTaps-2] * x[n-numTaps-1] + b[numTaps-3] * x[n-numTaps-2] +...+ b[0] * x[1] + * acc2 = b[numTaps-1] * x[n-numTaps+1] + b[numTaps-2] * x[n-numTaps] + b[numTaps-3] * x[n-numTaps-1] +...+ b[0] * x[2] + * acc3 = b[numTaps-1] * x[n-numTaps+2] + b[numTaps-2] * x[n-numTaps+1] + b[numTaps-3] * x[n-numTaps] +...+ b[0] * x[3] + */ + blkCnt = blockSize >> 3; + + /* First part of the processing with loop unrolling. Compute 8 outputs at a time. + ** a second loop below computes the remaining 1 to 7 samples. */ + while(blkCnt > 0u) + { + /* Copy four new input samples into the state buffer */ + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + + /* Set all accumulators to zero */ + acc0 = 0.0f; + acc1 = 0.0f; + acc2 = 0.0f; + acc3 = 0.0f; + acc4 = 0.0f; + acc5 = 0.0f; + acc6 = 0.0f; + acc7 = 0.0f; + + /* Initialize state pointer */ + px = pState; + + /* Initialize coeff pointer */ + pb = (pCoeffs); + + /* This is separated from the others to avoid + * a call to __aeabi_memmove which would be slower + */ + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + + /* Read the first seven samples from the state buffer: x[n-numTaps], x[n-numTaps-1], x[n-numTaps-2] */ + x0 = *px++; + x1 = *px++; + x2 = *px++; + x3 = *px++; + x4 = *px++; + x5 = *px++; + x6 = *px++; + + /* Loop unrolling. Process 8 taps at a time. */ + tapCnt = numTaps >> 3u; + + /* Loop over the number of taps. Unroll by a factor of 8. + ** Repeat until we've computed numTaps-8 coefficients. */ + while(tapCnt > 0u) + { + /* Read the b[numTaps-1] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-3] sample */ + x7 = *(px++); + + /* acc0 += b[numTaps-1] * x[n-numTaps] */ + acc0 += x0 * c0; + + /* acc1 += b[numTaps-1] * x[n-numTaps-1] */ + acc1 += x1 * c0; + + /* acc2 += b[numTaps-1] * x[n-numTaps-2] */ + acc2 += x2 * c0; + + /* acc3 += b[numTaps-1] * x[n-numTaps-3] */ + acc3 += x3 * c0; + + /* acc4 += b[numTaps-1] * x[n-numTaps-4] */ + acc4 += x4 * c0; + + /* acc1 += b[numTaps-1] * x[n-numTaps-5] */ + acc5 += x5 * c0; + + /* acc2 += b[numTaps-1] * x[n-numTaps-6] */ + acc6 += x6 * c0; + + /* acc3 += b[numTaps-1] * x[n-numTaps-7] */ + acc7 += x7 * c0; + + /* Read the b[numTaps-2] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-4] sample */ + x0 = *(px++); + + /* Perform the multiply-accumulate */ + acc0 += x1 * c0; + acc1 += x2 * c0; + acc2 += x3 * c0; + acc3 += x4 * c0; + acc4 += x5 * c0; + acc5 += x6 * c0; + acc6 += x7 * c0; + acc7 += x0 * c0; + + /* Read the b[numTaps-3] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-5] sample */ + x1 = *(px++); + + /* Perform the multiply-accumulates */ + acc0 += x2 * c0; + acc1 += x3 * c0; + acc2 += x4 * c0; + acc3 += x5 * c0; + acc4 += x6 * c0; + acc5 += x7 * c0; + acc6 += x0 * c0; + acc7 += x1 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x2 = *(px++); + + /* Perform the multiply-accumulates */ + acc0 += x3 * c0; + acc1 += x4 * c0; + acc2 += x5 * c0; + acc3 += x6 * c0; + acc4 += x7 * c0; + acc5 += x0 * c0; + acc6 += x1 * c0; + acc7 += x2 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x3 = *(px++); + /* Perform the multiply-accumulates */ + acc0 += x4 * c0; + acc1 += x5 * c0; + acc2 += x6 * c0; + acc3 += x7 * c0; + acc4 += x0 * c0; + acc5 += x1 * c0; + acc6 += x2 * c0; + acc7 += x3 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x4 = *(px++); + + /* Perform the multiply-accumulates */ + acc0 += x5 * c0; + acc1 += x6 * c0; + acc2 += x7 * c0; + acc3 += x0 * c0; + acc4 += x1 * c0; + acc5 += x2 * c0; + acc6 += x3 * c0; + acc7 += x4 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x5 = *(px++); + + /* Perform the multiply-accumulates */ + acc0 += x6 * c0; + acc1 += x7 * c0; + acc2 += x0 * c0; + acc3 += x1 * c0; + acc4 += x2 * c0; + acc5 += x3 * c0; + acc6 += x4 * c0; + acc7 += x5 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x6 = *(px++); + + /* Perform the multiply-accumulates */ + acc0 += x7 * c0; + acc1 += x0 * c0; + acc2 += x1 * c0; + acc3 += x2 * c0; + acc4 += x3 * c0; + acc5 += x4 * c0; + acc6 += x5 * c0; + acc7 += x6 * c0; + + tapCnt--; + } + + /* If the filter length is not a multiple of 8, compute the remaining filter taps */ + tapCnt = numTaps % 0x8u; + + while(tapCnt > 0u) + { + /* Read coefficients */ + c0 = *(pb++); + + /* Fetch 1 state variable */ + x7 = *(px++); + + /* Perform the multiply-accumulates */ + acc0 += x0 * c0; + acc1 += x1 * c0; + acc2 += x2 * c0; + acc3 += x3 * c0; + acc4 += x4 * c0; + acc5 += x5 * c0; + acc6 += x6 * c0; + acc7 += x7 * c0; + + /* Reuse the present sample states for next sample */ + x0 = x1; + x1 = x2; + x2 = x3; + x3 = x4; + x4 = x5; + x5 = x6; + x6 = x7; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Advance the state pointer by 8 to process the next group of 8 samples */ + pState = pState + 8; + + /* The results in the 8 accumulators, store in the destination buffer. */ + *pDst++ = acc0; + *pDst++ = acc1; + *pDst++ = acc2; + *pDst++ = acc3; + *pDst++ = acc4; + *pDst++ = acc5; + *pDst++ = acc6; + *pDst++ = acc7; + + blkCnt--; + } + + /* If the blockSize is not a multiple of 8, compute any remaining output samples here. + ** No loop unrolling is used. */ + blkCnt = blockSize % 0x8u; + + while(blkCnt > 0u) + { + /* Copy one sample at a time into state buffer */ + *pStateCurnt++ = *pSrc++; + + /* Set the accumulator to zero */ + acc0 = 0.0f; + + /* Initialize state pointer */ + px = pState; + + /* Initialize Coefficient pointer */ + pb = (pCoeffs); + + i = numTaps; + + /* Perform the multiply-accumulates */ + do + { + acc0 += *px++ * *pb++; + i--; + + } while(i > 0u); + + /* The result is store in the destination buffer. */ + *pDst++ = acc0; + + /* Advance state pointer by 1 for the next sample */ + pState = pState + 1; + + blkCnt--; + } + + /* Processing is complete. + ** Now copy the last numTaps - 1 samples to the start of the state buffer. + ** This prepares the state buffer for the next function call. */ + + /* Points to the start of the state buffer */ + pStateCurnt = S->pState; + + tapCnt = (numTaps - 1u) >> 2u; + + /* copy data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Calculate remaining number of copies */ + tapCnt = (numTaps - 1u) % 0x4u; + + /* Copy the remaining q31_t data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } +} + +#elif defined(ARM_MATH_CM0_FAMILY) + +void arm_fir_f32( +const arm_fir_instance_f32 * S, +float32_t * pSrc, +float32_t * pDst, +uint32_t blockSize) +{ + float32_t *pState = S->pState; /* State pointer */ + float32_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + float32_t *pStateCurnt; /* Points to the current sample of the state */ + float32_t *px, *pb; /* Temporary pointers for state and coefficient buffers */ + uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ + uint32_t i, tapCnt, blkCnt; /* Loop counters */ + + /* Run the below code for Cortex-M0 */ + + float32_t acc; + + /* S->pState points to state array which contains previous frame (numTaps - 1) samples */ + /* pStateCurnt points to the location where the new input data should be written */ + pStateCurnt = &(S->pState[(numTaps - 1u)]); + + /* Initialize blkCnt with blockSize */ + blkCnt = blockSize; + + while(blkCnt > 0u) + { + /* Copy one sample at a time into state buffer */ + *pStateCurnt++ = *pSrc++; + + /* Set the accumulator to zero */ + acc = 0.0f; + + /* Initialize state pointer */ + px = pState; + + /* Initialize Coefficient pointer */ + pb = pCoeffs; + + i = numTaps; + + /* Perform the multiply-accumulates */ + do + { + /* acc = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] */ + acc += *px++ * *pb++; + i--; + + } while(i > 0u); + + /* The result is store in the destination buffer. */ + *pDst++ = acc; + + /* Advance state pointer by 1 for the next sample */ + pState = pState + 1; + + blkCnt--; + } + + /* Processing is complete. + ** Now copy the last numTaps - 1 samples to the starting of the state buffer. + ** This prepares the state buffer for the next function call. */ + + /* Points to the start of the state buffer */ + pStateCurnt = S->pState; + + /* Copy numTaps number of values */ + tapCnt = numTaps - 1u; + + /* Copy data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } + +} + +#else + +/* Run the below code for Cortex-M4 and Cortex-M3 */ + +void arm_fir_f32( +const arm_fir_instance_f32 * S, +float32_t * pSrc, +float32_t * pDst, +uint32_t blockSize) +{ + float32_t *pState = S->pState; /* State pointer */ + float32_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + float32_t *pStateCurnt; /* Points to the current sample of the state */ + float32_t *px, *pb; /* Temporary pointers for state and coefficient buffers */ + float32_t acc0, acc1, acc2, acc3, acc4, acc5, acc6, acc7; /* Accumulators */ + float32_t x0, x1, x2, x3, x4, x5, x6, x7, c0; /* Temporary variables to hold state and coefficient values */ + uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ + uint32_t i, tapCnt, blkCnt; /* Loop counters */ + float32_t p0,p1,p2,p3,p4,p5,p6,p7; /* Temporary product values */ + + /* S->pState points to state array which contains previous frame (numTaps - 1) samples */ + /* pStateCurnt points to the location where the new input data should be written */ + pStateCurnt = &(S->pState[(numTaps - 1u)]); + + /* Apply loop unrolling and compute 8 output values simultaneously. + * The variables acc0 ... acc7 hold output values that are being computed: + * + * acc0 = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] + * acc1 = b[numTaps-1] * x[n-numTaps] + b[numTaps-2] * x[n-numTaps-1] + b[numTaps-3] * x[n-numTaps-2] +...+ b[0] * x[1] + * acc2 = b[numTaps-1] * x[n-numTaps+1] + b[numTaps-2] * x[n-numTaps] + b[numTaps-3] * x[n-numTaps-1] +...+ b[0] * x[2] + * acc3 = b[numTaps-1] * x[n-numTaps+2] + b[numTaps-2] * x[n-numTaps+1] + b[numTaps-3] * x[n-numTaps] +...+ b[0] * x[3] + */ + blkCnt = blockSize >> 3; + + /* First part of the processing with loop unrolling. Compute 8 outputs at a time. + ** a second loop below computes the remaining 1 to 7 samples. */ + while(blkCnt > 0u) + { + /* Copy four new input samples into the state buffer */ + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + + /* Set all accumulators to zero */ + acc0 = 0.0f; + acc1 = 0.0f; + acc2 = 0.0f; + acc3 = 0.0f; + acc4 = 0.0f; + acc5 = 0.0f; + acc6 = 0.0f; + acc7 = 0.0f; + + /* Initialize state pointer */ + px = pState; + + /* Initialize coeff pointer */ + pb = (pCoeffs); + + /* This is separated from the others to avoid + * a call to __aeabi_memmove which would be slower + */ + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + *pStateCurnt++ = *pSrc++; + + /* Read the first seven samples from the state buffer: x[n-numTaps], x[n-numTaps-1], x[n-numTaps-2] */ + x0 = *px++; + x1 = *px++; + x2 = *px++; + x3 = *px++; + x4 = *px++; + x5 = *px++; + x6 = *px++; + + /* Loop unrolling. Process 8 taps at a time. */ + tapCnt = numTaps >> 3u; + + /* Loop over the number of taps. Unroll by a factor of 8. + ** Repeat until we've computed numTaps-8 coefficients. */ + while(tapCnt > 0u) + { + /* Read the b[numTaps-1] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-3] sample */ + x7 = *(px++); + + /* acc0 += b[numTaps-1] * x[n-numTaps] */ + p0 = x0 * c0; + + /* acc1 += b[numTaps-1] * x[n-numTaps-1] */ + p1 = x1 * c0; + + /* acc2 += b[numTaps-1] * x[n-numTaps-2] */ + p2 = x2 * c0; + + /* acc3 += b[numTaps-1] * x[n-numTaps-3] */ + p3 = x3 * c0; + + /* acc4 += b[numTaps-1] * x[n-numTaps-4] */ + p4 = x4 * c0; + + /* acc1 += b[numTaps-1] * x[n-numTaps-5] */ + p5 = x5 * c0; + + /* acc2 += b[numTaps-1] * x[n-numTaps-6] */ + p6 = x6 * c0; + + /* acc3 += b[numTaps-1] * x[n-numTaps-7] */ + p7 = x7 * c0; + + /* Read the b[numTaps-2] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-4] sample */ + x0 = *(px++); + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + + /* Perform the multiply-accumulate */ + p0 = x1 * c0; + p1 = x2 * c0; + p2 = x3 * c0; + p3 = x4 * c0; + p4 = x5 * c0; + p5 = x6 * c0; + p6 = x7 * c0; + p7 = x0 * c0; + + /* Read the b[numTaps-3] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-5] sample */ + x1 = *(px++); + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + /* Perform the multiply-accumulates */ + p0 = x2 * c0; + p1 = x3 * c0; + p2 = x4 * c0; + p3 = x5 * c0; + p4 = x6 * c0; + p5 = x7 * c0; + p6 = x0 * c0; + p7 = x1 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x2 = *(px++); + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + /* Perform the multiply-accumulates */ + p0 = x3 * c0; + p1 = x4 * c0; + p2 = x5 * c0; + p3 = x6 * c0; + p4 = x7 * c0; + p5 = x0 * c0; + p6 = x1 * c0; + p7 = x2 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x3 = *(px++); + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + /* Perform the multiply-accumulates */ + p0 = x4 * c0; + p1 = x5 * c0; + p2 = x6 * c0; + p3 = x7 * c0; + p4 = x0 * c0; + p5 = x1 * c0; + p6 = x2 * c0; + p7 = x3 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x4 = *(px++); + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + /* Perform the multiply-accumulates */ + p0 = x5 * c0; + p1 = x6 * c0; + p2 = x7 * c0; + p3 = x0 * c0; + p4 = x1 * c0; + p5 = x2 * c0; + p6 = x3 * c0; + p7 = x4 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x5 = *(px++); + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + /* Perform the multiply-accumulates */ + p0 = x6 * c0; + p1 = x7 * c0; + p2 = x0 * c0; + p3 = x1 * c0; + p4 = x2 * c0; + p5 = x3 * c0; + p6 = x4 * c0; + p7 = x5 * c0; + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-6] sample */ + x6 = *(px++); + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + /* Perform the multiply-accumulates */ + p0 = x7 * c0; + p1 = x0 * c0; + p2 = x1 * c0; + p3 = x2 * c0; + p4 = x3 * c0; + p5 = x4 * c0; + p6 = x5 * c0; + p7 = x6 * c0; + + tapCnt--; + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + } + + /* If the filter length is not a multiple of 8, compute the remaining filter taps */ + tapCnt = numTaps % 0x8u; + + while(tapCnt > 0u) + { + /* Read coefficients */ + c0 = *(pb++); + + /* Fetch 1 state variable */ + x7 = *(px++); + + /* Perform the multiply-accumulates */ + p0 = x0 * c0; + p1 = x1 * c0; + p2 = x2 * c0; + p3 = x3 * c0; + p4 = x4 * c0; + p5 = x5 * c0; + p6 = x6 * c0; + p7 = x7 * c0; + + /* Reuse the present sample states for next sample */ + x0 = x1; + x1 = x2; + x2 = x3; + x3 = x4; + x4 = x5; + x5 = x6; + x6 = x7; + + acc0 += p0; + acc1 += p1; + acc2 += p2; + acc3 += p3; + acc4 += p4; + acc5 += p5; + acc6 += p6; + acc7 += p7; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Advance the state pointer by 8 to process the next group of 8 samples */ + pState = pState + 8; + + /* The results in the 8 accumulators, store in the destination buffer. */ + *pDst++ = acc0; + *pDst++ = acc1; + *pDst++ = acc2; + *pDst++ = acc3; + *pDst++ = acc4; + *pDst++ = acc5; + *pDst++ = acc6; + *pDst++ = acc7; + + blkCnt--; + } + + /* If the blockSize is not a multiple of 8, compute any remaining output samples here. + ** No loop unrolling is used. */ + blkCnt = blockSize % 0x8u; + + while(blkCnt > 0u) + { + /* Copy one sample at a time into state buffer */ + *pStateCurnt++ = *pSrc++; + + /* Set the accumulator to zero */ + acc0 = 0.0f; + + /* Initialize state pointer */ + px = pState; + + /* Initialize Coefficient pointer */ + pb = (pCoeffs); + + i = numTaps; + + /* Perform the multiply-accumulates */ + do + { + acc0 += *px++ * *pb++; + i--; + + } while(i > 0u); + + /* The result is store in the destination buffer. */ + *pDst++ = acc0; + + /* Advance state pointer by 1 for the next sample */ + pState = pState + 1; + + blkCnt--; + } + + /* Processing is complete. + ** Now copy the last numTaps - 1 samples to the start of the state buffer. + ** This prepares the state buffer for the next function call. */ + + /* Points to the start of the state buffer */ + pStateCurnt = S->pState; + + tapCnt = (numTaps - 1u) >> 2u; + + /* copy data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Calculate remaining number of copies */ + tapCnt = (numTaps - 1u) % 0x4u; + + /* Copy the remaining q31_t data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } +} + +#endif + +/** +* @} end of FIR group +*/ |