diff options
Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_fast_q31.c')
-rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_fast_q31.c | 299 |
1 files changed, 0 insertions, 299 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_fast_q31.c b/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_fast_q31.c deleted file mode 100644 index 1ba7e38c89..0000000000 --- a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_fast_q31.c +++ /dev/null @@ -1,299 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2013 ARM Limited. All rights reserved. -* -* $Date: 17. January 2013 -* $Revision: V1.4.1 -* -* Project: CMSIS DSP Library -* Title: arm_fir_fast_q31.c -* -* Description: Processing function for the Q31 Fast FIR filter. -* -* Target Processor: Cortex-M4/Cortex-M3 -* -* 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 FIR - * @{ - */ - -/** - * @param[in] *S points to an instance of the Q31 structure. - * @param[in] *pSrc points to the block of input data. - * @param[out] *pDst points to the block output data. - * @param[in] blockSize number of samples to process per call. - * @return none. - * - * <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 added to a 2.30 accumulator. - * Finally, the accumulator is saturated and converted to a 1.31 result. - * The fast version has the same overflow behavior as the standard version and provides less precision since it discards the low 32 bits of each multiplication result. - * In order to avoid overflows completely the input signal must be scaled down by log2(numTaps) bits. - * - * \par - * Refer to the function <code>arm_fir_q31()</code> for a slower implementation of this function which uses a 64-bit accumulator to provide higher precision. Both the slow and the fast versions use the same instance structure. - * Use the function <code>arm_fir_init_q31()</code> to initialize the filter structure. - */ - -IAR_ONLY_LOW_OPTIMIZATION_ENTER -void arm_fir_fast_q31( - const arm_fir_instance_q31 * S, - q31_t * pSrc, - q31_t * pDst, - uint32_t blockSize) -{ - q31_t *pState = S->pState; /* State pointer */ - q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - q31_t *pStateCurnt; /* Points to the current sample of the state */ - q31_t x0, x1, x2, x3; /* Temporary variables to hold state */ - q31_t c0; /* Temporary variable to hold coefficient value */ - q31_t *px; /* Temporary pointer for state */ - q31_t *pb; /* Temporary pointer for coefficient buffer */ - q31_t acc0, acc1, acc2, acc3; /* Accumulators */ - uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ - uint32_t i, tapCnt, blkCnt; /* Loop counters */ - - /* S->pState points to buffer 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 4 output values simultaneously. - * The variables acc0 ... acc3 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 >> 2; - - /* First part of the processing with loop unrolling. Compute 4 outputs at a time. - ** a second loop below computes the remaining 1 to 3 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; - acc1 = 0; - acc2 = 0; - acc3 = 0; - - /* Initialize state pointer */ - px = pState; - - /* Initialize coefficient pointer */ - pb = pCoeffs; - - /* Read the first three samples from the state buffer: - * x[n-numTaps], x[n-numTaps-1], x[n-numTaps-2] */ - x0 = *(px++); - x1 = *(px++); - x2 = *(px++); - - /* Loop unrolling. Process 4 taps at a time. */ - tapCnt = numTaps >> 2; - i = tapCnt; - - while(i > 0u) - { - /* Read the b[numTaps] coefficient */ - c0 = *(pb++); - - /* Read x[n-numTaps-3] sample */ - x3 = *(px++); - - /* acc0 += b[numTaps] * x[n-numTaps] */ - multAcc_32x32_keep32_R(acc0, x0, c0); - - /* acc1 += b[numTaps] * x[n-numTaps-1] */ - multAcc_32x32_keep32_R(acc1, x1, c0); - - /* acc2 += b[numTaps] * x[n-numTaps-2] */ - multAcc_32x32_keep32_R(acc2, x2, c0); - - /* acc3 += b[numTaps] * x[n-numTaps-3] */ - multAcc_32x32_keep32_R(acc3, x3, c0); - - /* Read the b[numTaps-1] coefficient */ - c0 = *(pb++); - - /* Read x[n-numTaps-4] sample */ - x0 = *(px++); - - /* Perform the multiply-accumulates */ - multAcc_32x32_keep32_R(acc0, x1, c0); - multAcc_32x32_keep32_R(acc1, x2, c0); - multAcc_32x32_keep32_R(acc2, x3, c0); - multAcc_32x32_keep32_R(acc3, x0, c0); - - /* Read the b[numTaps-2] coefficient */ - c0 = *(pb++); - - /* Read x[n-numTaps-5] sample */ - x1 = *(px++); - - /* Perform the multiply-accumulates */ - multAcc_32x32_keep32_R(acc0, x2, c0); - multAcc_32x32_keep32_R(acc1, x3, c0); - multAcc_32x32_keep32_R(acc2, x0, c0); - multAcc_32x32_keep32_R(acc3, x1, c0); - - /* Read the b[numTaps-3] coefficients */ - c0 = *(pb++); - - /* Read x[n-numTaps-6] sample */ - x2 = *(px++); - - /* Perform the multiply-accumulates */ - multAcc_32x32_keep32_R(acc0, x3, c0); - multAcc_32x32_keep32_R(acc1, x0, c0); - multAcc_32x32_keep32_R(acc2, x1, c0); - multAcc_32x32_keep32_R(acc3, x2, c0); - i--; - } - - /* If the filter length is not a multiple of 4, compute the remaining filter taps */ - - i = numTaps - (tapCnt * 4u); - while(i > 0u) - { - /* Read coefficients */ - c0 = *(pb++); - - /* Fetch 1 state variable */ - x3 = *(px++); - - /* Perform the multiply-accumulates */ - multAcc_32x32_keep32_R(acc0, x0, c0); - multAcc_32x32_keep32_R(acc1, x1, c0); - multAcc_32x32_keep32_R(acc2, x2, c0); - multAcc_32x32_keep32_R(acc3, x3, c0); - - /* Reuse the present sample states for next sample */ - x0 = x1; - x1 = x2; - x2 = x3; - - /* Decrement the loop counter */ - i--; - } - - /* Advance the state pointer by 4 to process the next group of 4 samples */ - pState = pState + 4; - - /* The results in the 4 accumulators are in 2.30 format. Convert to 1.31 - ** Then store the 4 outputs in the destination buffer. */ - *pDst++ = (q31_t) (acc0 << 1); - *pDst++ = (q31_t) (acc1 << 1); - *pDst++ = (q31_t) (acc2 << 1); - *pDst++ = (q31_t) (acc3 << 1); - - /* Decrement the samples loop counter */ - blkCnt--; - } - - - /* If the blockSize is not a multiple of 4, compute any remaining output samples here. - ** No loop unrolling is used. */ - blkCnt = blockSize % 4u; - - while(blkCnt > 0u) - { - /* Copy one sample at a time into state buffer */ - *pStateCurnt++ = *pSrc++; - - /* Set the accumulator to zero */ - acc0 = 0; - - /* Initialize state pointer */ - px = pState; - - /* Initialize Coefficient pointer */ - pb = (pCoeffs); - - i = numTaps; - - /* Perform the multiply-accumulates */ - do - { - multAcc_32x32_keep32_R(acc0, (*px++), (*(pb++))); - i--; - } while(i > 0u); - - /* The result is in 2.30 format. Convert to 1.31 - ** Then store the output in the destination buffer. */ - *pDst++ = (q31_t) (acc0 << 1); - - /* Advance state pointer by 1 for the next sample */ - pState = pState + 1; - - /* Decrement the samples loop counter */ - 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; - - /* Calculate remaining number of copies */ - tapCnt = (numTaps - 1u); - - /* Copy the remaining q31_t data */ - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - tapCnt--; - } - - -} -IAR_ONLY_LOW_OPTIMIZATION_EXIT -/** - * @} end of FIR group - */ |