diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c')
-rw-r--r-- | Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c | 203 |
1 files changed, 90 insertions, 113 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c index ab517d886..1a568d70d 100644 --- a/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c +++ b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c @@ -3,13 +3,13 @@ * Title: arm_biquad_cascade_df1_fast_q15.c * Description: Fast processing function for the Q15 Biquad cascade filter * - * $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 * @@ -29,90 +29,87 @@ #include "arm_math.h" /** - * @ingroup groupFilters + @ingroup groupFilters */ /** - * @addtogroup BiquadCascadeDF1 - * @{ + @addtogroup BiquadCascadeDF1 + @{ */ /** - * @details - * @param[in] *S points to an instance of the Q15 Biquad cascade 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. - * - * <b>Scaling and Overflow Behavior:</b> - * \par - * This fast version uses a 32-bit accumulator with 2.30 format. - * The accumulator maintains full precision of the intermediate multiplication results but provides only a single guard bit. - * Thus, if the accumulator result overflows it wraps around and distorts the result. - * In order to avoid overflows completely the input signal must be scaled down by two bits and lie in the range [-0.25 +0.25). - * The 2.30 accumulator is then shifted by <code>postShift</code> bits and the result truncated to 1.15 format by discarding the low 16 bits. - * - * \par - * Refer to the function <code>arm_biquad_cascade_df1_q15()</code> for a slower implementation of this function which uses 64-bit accumulation to avoid wrap around distortion. Both the slow and the fast versions use the same instance structure. - * Use the function <code>arm_biquad_cascade_df1_init_q15()</code> to initialize the filter structure. - * + @brief Processing function for the Q15 Biquad cascade filter (fast variant). + @param[in] S points to an instance of the Q15 Biquad cascade 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 + + @par Scaling and Overflow Behavior + This fast version uses a 32-bit accumulator with 2.30 format. + The accumulator maintains full precision of the intermediate multiplication results but provides only a single guard bit. + Thus, if the accumulator result overflows it wraps around and distorts the result. + In order to avoid overflows completely the input signal must be scaled down by two bits and lie in the range [-0.25 +0.25). + The 2.30 accumulator is then shifted by <code>postShift</code> bits and the result truncated to 1.15 format by discarding the low 16 bits. + @remark + Refer to \ref arm_biquad_cascade_df1_q15() for a slower implementation of this function + which uses 64-bit accumulation to avoid wrap around distortion. Both the slow and the fast versions use the same instance structure. + Use the function \ref arm_biquad_cascade_df1_init_q15() to initialize the filter structure. */ void arm_biquad_cascade_df1_fast_q15( const arm_biquad_casd_df1_inst_q15 * S, - q15_t * pSrc, - q15_t * pDst, - uint32_t blockSize) + const q15_t * pSrc, + q15_t * pDst, + uint32_t blockSize) { - q15_t *pIn = pSrc; /* Source pointer */ - q15_t *pOut = pDst; /* Destination pointer */ - q31_t in; /* Temporary variable to hold input value */ - q31_t out; /* Temporary variable to hold output value */ - q31_t b0; /* Temporary variable to hold bo value */ - q31_t b1, a1; /* Filter coefficients */ - q31_t state_in, state_out; /* Filter state variables */ - q31_t acc; /* Accumulator */ - int32_t shift = (int32_t) (15 - S->postShift); /* Post shift */ - q15_t *pState = S->pState; /* State pointer */ - q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - uint32_t sample, stage = S->numStages; /* Stage loop counter */ - - + const q15_t *pIn = pSrc; /* Source pointer */ + q15_t *pOut = pDst; /* Destination pointer */ + q15_t *pState = S->pState; /* State pointer */ + const q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + q31_t acc; /* Accumulator */ + q31_t in; /* Temporary variable to hold input value */ + q31_t out; /* Temporary variable to hold output value */ + q31_t b0; /* Temporary variable to hold bo value */ + q31_t b1, a1; /* Filter coefficients */ + q31_t state_in, state_out; /* Filter state variables */ + int32_t shift = (int32_t) (15 - S->postShift); /* Post shift */ + uint32_t sample, stage = S->numStages; /* Loop counters */ do { - /* Read the b0 and 0 coefficients using SIMD */ - b0 = *__SIMD32(pCoeffs)++; + b0 = read_q15x2_ia ((q15_t **) &pCoeffs); /* Read the b1 and b2 coefficients using SIMD */ - b1 = *__SIMD32(pCoeffs)++; + b1 = read_q15x2_ia ((q15_t **) &pCoeffs); /* Read the a1 and a2 coefficients using SIMD */ - a1 = *__SIMD32(pCoeffs)++; + a1 = read_q15x2_ia ((q15_t **) &pCoeffs); /* Read the input state values from the state buffer: x[n-1], x[n-2] */ - state_in = *__SIMD32(pState)++; + state_in = read_q15x2_ia (&pState); /* Read the output state values from the state buffer: y[n-1], y[n-2] */ - state_out = *__SIMD32(pState)--; + state_out = read_q15x2_da (&pState); + +#if defined (ARM_MATH_LOOPUNROLL) /* Apply loop unrolling and compute 2 output values simultaneously. */ - /* The variable acc hold output values that are being computed: + /* Variable acc hold output values that are being computed: * - * acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] - * acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] + * acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] + * acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] */ + + /* Loop unrolling: Compute 2 outputs at a time */ sample = blockSize >> 1U; - /* First part of the processing with loop unrolling. Compute 2 outputs at a time. - ** a second loop below computes the remaining 1 sample. */ while (sample > 0U) { /* Read the input */ - in = *__SIMD32(pIn)++; + in = read_q15x2_ia ((q15_t **) &pIn); /* out = b0 * x[n] + 0 * 0 */ out = __SMUAD(b0, in); @@ -126,24 +123,20 @@ void arm_biquad_cascade_df1_fast_q15( /* Every time after the output is computed state should be updated. */ /* The states should be updated as: */ - /* Xn2 = Xn1 */ - /* Xn1 = Xn */ - /* Yn2 = Yn1 */ - /* Yn1 = acc */ + /* Xn2 = Xn1 */ + /* Xn1 = Xn */ + /* Yn2 = Yn1 */ + /* Yn1 = acc */ /* x[n-N], x[n-N-1] are packed together to make state_in of type q31 */ /* y[n-N], y[n-N-1] are packed together to make state_out of type q31 */ #ifndef ARM_MATH_BIG_ENDIAN - - state_in = __PKHBT(in, state_in, 16); + state_in = __PKHBT(in, state_in, 16); state_out = __PKHBT(out, state_out, 16); - #else - - state_in = __PKHBT(state_in >> 16, (in >> 16), 16); + state_in = __PKHBT(state_in >> 16, (in >> 16), 16); state_out = __PKHBT(state_out >> 16, (out), 16); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ +#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ /* out = b0 * x[n] + 0 * 0 */ out = __SMUADX(b0, in); @@ -155,64 +148,53 @@ void arm_biquad_cascade_df1_fast_q15( /* The result is converted from 3.29 to 1.31 and then saturation is applied */ out = __SSAT((acc >> shift), 16); - /* Store the output in the destination buffer. */ - #ifndef ARM_MATH_BIG_ENDIAN - - *__SIMD32(pOut)++ = __PKHBT(state_out, out, 16); - + write_q15x2_ia (&pOut, __PKHBT(state_out, out, 16)); #else - - *__SIMD32(pOut)++ = __PKHBT(out, state_out >> 16, 16); - + write_q15x2_ia (&pOut, __PKHBT(out, state_out >> 16, 16)); #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ /* Every time after the output is computed state should be updated. */ /* The states should be updated as: */ - /* Xn2 = Xn1 */ - /* Xn1 = Xn */ - /* Yn2 = Yn1 */ - /* Yn1 = acc */ + /* Xn2 = Xn1 */ + /* Xn1 = Xn */ + /* Yn2 = Yn1 */ + /* Yn1 = acc */ /* x[n-N], x[n-N-1] are packed together to make state_in of type q31 */ /* y[n-N], y[n-N-1] are packed together to make state_out of type q31 */ - #ifndef ARM_MATH_BIG_ENDIAN - - state_in = __PKHBT(in >> 16, state_in, 16); + state_in = __PKHBT(in >> 16, state_in, 16); state_out = __PKHBT(out, state_out, 16); - #else - - state_in = __PKHBT(state_in >> 16, in, 16); + state_in = __PKHBT(state_in >> 16, in, 16); state_out = __PKHBT(state_out >> 16, out, 16); - #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - /* Decrement the loop counter */ + /* Decrement loop counter */ sample--; - } - /* If the blockSize is not a multiple of 2, compute any remaining output samples here. - ** No loop unrolling is used. */ + /* Loop unrolling: Compute remaining outputs */ + sample = (blockSize & 0x1U); + +#else + + /* Initialize blkCnt with number of samples */ + sample = blockSize; + +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ - if ((blockSize & 0x1U) != 0U) + while (sample > 0U) { /* Read the input */ in = *pIn++; /* out = b0 * x[n] + 0 * 0 */ - #ifndef ARM_MATH_BIG_ENDIAN - out = __SMUAD(b0, in); - #else - out = __SMUADX(b0, in); - #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ /* acc = b1 * x[n-1], acc += b2 * x[n-2] + out */ @@ -228,46 +210,41 @@ void arm_biquad_cascade_df1_fast_q15( /* Every time after the output is computed state should be updated. */ /* The states should be updated as: */ - /* Xn2 = Xn1 */ - /* Xn1 = Xn */ - /* Yn2 = Yn1 */ - /* Yn1 = acc */ + /* Xn2 = Xn1 */ + /* Xn1 = Xn */ + /* Yn2 = Yn1 */ + /* Yn1 = acc */ /* x[n-N], x[n-N-1] are packed together to make state_in of type q31 */ /* y[n-N], y[n-N-1] are packed together to make state_out of type q31 */ - #ifndef ARM_MATH_BIG_ENDIAN - state_in = __PKHBT(in, state_in, 16); state_out = __PKHBT(out, state_out, 16); - #else - state_in = __PKHBT(state_in >> 16, in, 16); state_out = __PKHBT(state_out >> 16, out, 16); - #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ + /* decrement loop counter */ + sample--; } - /* The first stage goes from the input buffer to the output buffer. */ - /* Subsequent (numStages - 1) occur in-place in the output buffer */ + /* The first stage goes from the input buffer to the output buffer. */ + /* Subsequent (numStages - 1) occur in-place in the output buffer */ pIn = pDst; /* Reset the output pointer */ pOut = pDst; - /* Store the updated state variables back into the state array */ - *__SIMD32(pState)++ = state_in; - *__SIMD32(pState)++ = state_out; + /* Store the updated state variables back into the state array */ + write_q15x2_ia(&pState, state_in); + write_q15x2_ia(&pState, state_out); - - /* Decrement the loop counter */ + /* Decrement loop counter */ stage--; } while (stage > 0U); } - /** - * @} end of BiquadCascadeDF1 group + @} end of BiquadCascadeDF1 group */ |