diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_f32.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_f32.c | 1350 |
1 files changed, 540 insertions, 810 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_f32.c b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_f32.c index 61ec80a13..0531cfeb1 100644 --- a/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_f32.c +++ b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_f32.c @@ -3,13 +3,13 @@ * Title: arm_fir_f32.c * Description: Floating-point FIR filter processing function * - * $Date: 27. January 2017 - * $Revision: V.1.5.1 + * $Date: 18. March 2019 + * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* - * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * @@ -29,374 +29,259 @@ #include "arm_math.h" /** -* @ingroup groupFilters -*/ + @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. -*/ + @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 -* @{ -*/ + @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) + @brief Processing function for floating-point FIR filter. + @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 + @return none + */ +#if defined(ARM_MATH_NEON) void arm_fir_f32( const arm_fir_instance_f32 * S, -float32_t * pSrc, +const float32_t * pSrc, float32_t * pDst, uint32_t blockSize) { float32_t *pState = S->pState; /* State pointer */ - float32_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + const 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 */ + float32_t *px; /* Temporary pointers for state buffer */ + const float32_t *pb; /* Temporary pointers for coefficient buffer */ uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ uint32_t i, tapCnt, blkCnt; /* Loop counters */ + float32x4_t accv0,accv1,samples0,samples1,x0,x1,x2,xa,xb,x,b,accv; + uint32x4_t x0_u,x1_u,x2_u,xa_u,xb_u; + 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)]); - /* 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] - */ + /* Loop unrolling */ 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++; + /* Copy 8 samples at a time into state buffers */ + samples0 = vld1q_f32(pSrc); + vst1q_f32(pStateCurnt,samples0); + + pStateCurnt += 4; + pSrc += 4 ; - /* 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; + samples1 = vld1q_f32(pSrc); + vst1q_f32(pStateCurnt,samples1); + + pStateCurnt += 4; + pSrc += 4 ; + + /* Set the accumulators to zero */ + accv0 = vdupq_n_f32(0); + accv1 = vdupq_n_f32(0); /* Initialize state pointer */ px = pState; - /* Initialize coeff pointer */ - pb = (pCoeffs); + /* Initialize coefficient pointer */ + pb = pCoeffs; + + /* Loop unroling */ + i = numTaps >> 2; - /* 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++; + /* Perform the multiply-accumulates */ + x0 = vld1q_f32(px); + x1 = vld1q_f32(px + 4); - /* 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) + while(i > 0) { - /* 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--; + /* 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] */ + x2 = vld1q_f32(px + 8); + b = vld1q_f32(pb); + xa = x0; + xb = x1; + accv0 = vmlaq_n_f32(accv0,xa,b[0]); + accv1 = vmlaq_n_f32(accv1,xb,b[0]); + + xa = vextq_f32(x0,x1,1); + xb = vextq_f32(x1,x2,1); + + accv0 = vmlaq_n_f32(accv0,xa,b[1]); + accv1 = vmlaq_n_f32(accv1,xb,b[1]); + + xa = vextq_f32(x0,x1,2); + xb = vextq_f32(x1,x2,2); + + accv0 = vmlaq_n_f32(accv0,xa,b[2]); + accv1 = vmlaq_n_f32(accv1,xb,b[2]); + + xa = vextq_f32(x0,x1,3); + xb = vextq_f32(x1,x2,3); + + accv0 = vmlaq_n_f32(accv0,xa,b[3]); + accv1 = vmlaq_n_f32(accv1,xb,b[3]); + + pb += 4; + x0 = x1; + x1 = x2; + px += 4; + i--; + } - /* If the filter length is not a multiple of 8, compute the remaining filter taps */ - tapCnt = numTaps % 0x8U; + /* Tail */ + i = numTaps & 3; + x2 = vld1q_f32(px + 8); - while (tapCnt > 0U) + /* Perform the multiply-accumulates */ + switch(i) { - /* 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--; + case 3: + { + accv0 = vmlaq_n_f32(accv0,x0,*pb); + accv1 = vmlaq_n_f32(accv1,x1,*pb); + + pb++; + + xa = vextq_f32(x0,x1,1); + xb = vextq_f32(x1,x2,1); + + accv0 = vmlaq_n_f32(accv0,xa,*pb); + accv1 = vmlaq_n_f32(accv1,xb,*pb); + + pb++; + + xa = vextq_f32(x0,x1,2); + xb = vextq_f32(x1,x2,2); + + accv0 = vmlaq_n_f32(accv0,xa,*pb); + accv1 = vmlaq_n_f32(accv1,xb,*pb); + + } + break; + case 2: + { + accv0 = vmlaq_n_f32(accv0,x0,*pb); + accv1 = vmlaq_n_f32(accv1,x1,*pb); + + pb++; + + xa = vextq_f32(x0,x1,1); + xb = vextq_f32(x1,x2,1); + + accv0 = vmlaq_n_f32(accv0,xa,*pb); + accv1 = vmlaq_n_f32(accv1,xb,*pb); + + } + break; + case 1: + { + + accv0 = vmlaq_n_f32(accv0,x0,*pb); + accv1 = vmlaq_n_f32(accv1,x1,*pb); + + } + break; + default: + break; } - /* Advance the state pointer by 8 to process the next group of 8 samples */ - pState = pState + 8; + /* The result is stored in the destination buffer. */ + vst1q_f32(pDst,accv0); + pDst += 4; + vst1q_f32(pDst,accv1); + pDst += 4; - /* 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; + /* Advance state pointer by 8 for the next 8 samples */ + pState = pState + 8; blkCnt--; } - /* If the blockSize is not a multiple of 8, compute any remaining output samples here. - ** No loop unrolling is used. */ - blkCnt = blockSize % 0x8U; + /* Tail */ + blkCnt = blockSize & 0x7; while (blkCnt > 0U) { @@ -404,26 +289,27 @@ uint32_t blockSize) *pStateCurnt++ = *pSrc++; /* Set the accumulator to zero */ - acc0 = 0.0f; + acc = 0.0f; /* Initialize state pointer */ px = pState; /* Initialize Coefficient pointer */ - pb = (pCoeffs); + pb = pCoeffs; i = numTaps; /* Perform the multiply-accumulates */ do { - acc0 += *px++ * *pb++; + /* 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++ = acc0; + /* The result is stored in the destination buffer. */ + *pDst++ = acc; /* Advance state pointer by 1 for the next sample */ pState = pState + 1; @@ -432,554 +318,398 @@ uint32_t blockSize) } /* Processing is complete. - ** Now copy the last numTaps - 1 samples to the start of the state buffer. + ** 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; - tapCnt = (numTaps - 1U) >> 2U; + /* Copy numTaps number of values */ + tapCnt = numTaps - 1U; - /* copy data */ + /* 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) - +#else void arm_fir_f32( -const arm_fir_instance_f32 * S, -float32_t * pSrc, -float32_t * pDst, -uint32_t blockSize) + const arm_fir_instance_f32 * S, + const 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 */ + float32_t *pState = S->pState; /* State pointer */ + const float32_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + float32_t *pStateCurnt; /* Points to the current sample of the state */ + float32_t *px; /* Temporary pointer for state buffer */ + const float32_t *pb; /* Temporary pointer for coefficient buffer */ + float32_t acc0; /* Accumulator */ + uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ + uint32_t i, tapCnt, blkCnt; /* Loop counters */ + +#if defined (ARM_MATH_LOOPUNROLL) + float32_t acc1, acc2, acc3, acc4, acc5, acc6, acc7; /* Accumulators */ + float32_t x0, x1, x2, x3, x4, x5, x6, x7; /* Temporary variables to hold state values */ + float32_t c0; /* Temporary variable to hold coefficient value */ +#endif - /* Run the below code for Cortex-M0 */ + /* 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)]); + +#if defined (ARM_MATH_LOOPUNROLL) + + /* Loop unrolling: 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 >> 3U; + + while (blkCnt > 0U) + { + /* Copy 4 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 coefficient 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 7 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; + + 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++); - float32_t acc; + /* 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; - /* 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)]); + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); - /* Initialize blkCnt with blockSize */ - blkCnt = blockSize; + /* Read x[n-numTaps-6] sample */ + x2 = *(px++); - 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; + /* 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; - /* Initialize Coefficient pointer */ - pb = pCoeffs; + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); - i = numTaps; + /* Read x[n-numTaps-6] sample */ + x4 = *(px++); /* 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); + acc0 += x5 * c0; + acc1 += x6 * c0; + acc2 += x7 * c0; + acc3 += x0 * c0; + acc4 += x1 * c0; + acc5 += x2 * c0; + acc6 += x3 * c0; + acc7 += x4 * c0; - /* The result is store in the destination buffer. */ - *pDst++ = acc; + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); - /* Advance state pointer by 1 for the next sample */ - pState = pState + 1; + /* Read x[n-numTaps-6] sample */ + x5 = *(px++); - blkCnt--; - } + /* 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; - /* 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. */ + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); - /* Points to the start of the state buffer */ - pStateCurnt = S->pState; + /* Read x[n-numTaps-6] sample */ + x6 = *(px++); - /* Copy numTaps number of values */ - tapCnt = numTaps - 1U; - - /* Copy data */ - while (tapCnt > 0U) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ + /* 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; + + /* Decrement loop counter */ tapCnt--; - } + } -} + /* Loop unrolling: Compute remaining outputs */ + tapCnt = numTaps % 0x8U; -#else + while (tapCnt > 0U) + { + /* Read coefficients */ + c0 = *(pb++); -/* Run the below code for Cortex-M4 and Cortex-M3 */ + /* Fetch 1 state variable */ + x7 = *(px++); -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 */ + /* 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 loop counter */ + tapCnt--; + } - /* 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)]); + /* Advance the state pointer by 8 to process the next group of 8 samples */ + pState = pState + 8; - /* 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; + /* 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; - /* 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; + /* Decrement loop counter */ + blkCnt--; + } - /* Initialize state pointer */ - px = pState; + /* Loop unrolling: Compute remaining output samples */ + blkCnt = blockSize % 0x8U; - /* Initialize coeff pointer */ - pb = (pCoeffs); +#else - /* 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++; + /* Initialize blkCnt with number of taps */ + blkCnt = blockSize; - /* 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; - } +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ - /* If the filter length is not a multiple of 8, compute the remaining filter taps */ - tapCnt = numTaps % 0x8U; + while (blkCnt > 0U) + { + /* Copy one sample at a time into state buffer */ + *pStateCurnt++ = *pSrc++; - 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; + /* Set the accumulator to zero */ + acc0 = 0.0f; - /* 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; + /* Initialize state pointer */ + px = pState; - blkCnt--; - } + /* Initialize Coefficient pointer */ + pb = pCoeffs; - /* If the blockSize is not a multiple of 8, compute any remaining output samples here. - ** No loop unrolling is used. */ - blkCnt = blockSize % 0x8U; + i = numTaps; - while (blkCnt > 0U) - { - /* Copy one sample at a time into state buffer */ - *pStateCurnt++ = *pSrc++; + /* 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] */ + acc0 += *px++ * *pb++; - /* Set the accumulator to zero */ - acc0 = 0.0f; + i--; + } while (i > 0U); - /* Initialize state pointer */ - px = pState; + /* Store result in destination buffer. */ + *pDst++ = acc0; - /* Initialize Coefficient pointer */ - pb = (pCoeffs); + /* Advance state pointer by 1 for the next sample */ + pState = pState + 1U; - i = numTaps; + /* Decrement loop counter */ + blkCnt--; + } - /* Perform the multiply-accumulates */ - do - { - acc0 += *px++ * *pb++; - i--; + /* 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. */ - } while (i > 0U); + /* Points to the start of the state buffer */ + pStateCurnt = S->pState; - /* The result is store in the destination buffer. */ - *pDst++ = acc0; +#if defined (ARM_MATH_LOOPUNROLL) - /* Advance state pointer by 1 for the next sample */ - pState = pState + 1; + /* Loop unrolling: Compute 4 taps at a time */ + tapCnt = (numTaps - 1U) >> 2U; - blkCnt--; - } + /* Copy data */ + while (tapCnt > 0U) + { + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; - /* 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. */ + /* Decrement loop counter */ + tapCnt--; + } - /* Points to the start of the state buffer */ - pStateCurnt = S->pState; + /* Calculate remaining number of copies */ + tapCnt = (numTaps - 1U) % 0x4U; - tapCnt = (numTaps - 1U) >> 2U; +#else - /* copy data */ - while (tapCnt > 0U) - { - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; + /* Initialize tapCnt with number of taps */ + tapCnt = (numTaps - 1U); - /* Decrement the loop counter */ - tapCnt--; - } +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ - /* Calculate remaining number of copies */ - tapCnt = (numTaps - 1U) % 0x4U; + /* Copy remaining data */ + while (tapCnt > 0U) + { + *pStateCurnt++ = *pState++; - /* Copy the remaining q31_t data */ - while (tapCnt > 0U) - { - *pStateCurnt++ = *pState++; + /* Decrement loop counter */ + tapCnt--; + } - /* Decrement the loop counter */ - tapCnt--; - } } -#endif - +#endif /* #if defined(ARM_MATH_NEON) */ /** * @} end of FIR group */ |