diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_conv_fast_opt_q15.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_conv_fast_opt_q15.c | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_conv_fast_opt_q15.c b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_conv_fast_opt_q15.c new file mode 100644 index 0000000..b2144ad --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_conv_fast_opt_q15.c @@ -0,0 +1,366 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_conv_fast_opt_q15.c
+ * Description: Fast Q15 Convolution
+ *
+ * $Date: 18. March 2019
+ * $Revision: V1.6.0
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "arm_math.h"
+
+/**
+ @ingroup groupFilters
+ */
+
+/**
+ @addtogroup Conv
+ @{
+ */
+
+/**
+ @brief Convolution of Q15 sequences (fast version).
+ @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 srcALen+srcBLen-1
+ @param[in] pScratch1 points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2
+ @param[in] pScratch2 points to scratch buffer of size min(srcALen, srcBLen
+ @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. There is no saturation on intermediate additions.
+ Thus, if the accumulator overflows it wraps around and distorts the result.
+ The input signals should be scaled down to avoid intermediate overflows.
+ Scale down the inputs by log2(min(srcALen, srcBLen)) (log2 is read as log to the base 2) times to avoid overflows,
+ as maximum of min(srcALen, srcBLen) number of additions are carried internally.
+ The 2.30 accumulator is right shifted by 15 bits and then saturated to 1.15 format to yield the final result.
+
+ @remark
+ Refer to \ref arm_conv_q15() for a slower implementation of this function which uses 64-bit accumulation to avoid wrap around distortion.
+ */
+
+void arm_conv_fast_opt_q15(
+ const q15_t * pSrcA,
+ uint32_t srcALen,
+ const q15_t * pSrcB,
+ uint32_t srcBLen,
+ q15_t * pDst,
+ q15_t * pScratch1,
+ q15_t * pScratch2)
+{
+ q31_t acc0; /* Accumulators */
+ const q15_t *pIn1; /* InputA pointer */
+ const q15_t *pIn2; /* InputB pointer */
+ q15_t *pOut = pDst; /* Output pointer */
+ q15_t *pScr1 = pScratch1; /* Temporary pointer for scratch1 */
+ q15_t *pScr2 = pScratch2; /* Temporary pointer for scratch1 */
+ const q15_t *px; /* Intermediate inputA pointer */
+ q15_t *py; /* Intermediate inputB pointer */
+ uint32_t j, k, blkCnt; /* Loop counter */
+ uint32_t tapCnt; /* Loop count */
+
+#if defined (ARM_MATH_LOOPUNROLL)
+ q31_t acc1, acc2, acc3; /* Accumulators */
+ q31_t x1, x2, x3; /* Temporary variables to hold state and coefficient values */
+ q31_t y1, y2; /* State variables */
+#endif
+
+
+ /* 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;
+ }
+ 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;
+ }
+
+ /* Pointer to take end of scratch2 buffer */
+ pScr2 = pScratch2 + srcBLen - 1;
+
+ /* points to smaller length sequence */
+ px = pIn2;
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ k = srcBLen >> 2U;
+
+ /* Copy smaller length input sequence in reverse order into second scratch buffer */
+ while (k > 0U)
+ {
+ /* copy second buffer in reversal manner */
+ *pScr2-- = *px++;
+ *pScr2-- = *px++;
+ *pScr2-- = *px++;
+ *pScr2-- = *px++;
+
+ /* Decrement loop counter */
+ k--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ k = srcBLen % 0x4U;
+
+#else
+
+ /* Initialize k with number of samples */
+ k = srcBLen;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (k > 0U)
+ {
+ /* copy second buffer in reversal manner for remaining samples */
+ *pScr2-- = *px++;
+
+ /* Decrement loop counter */
+ k--;
+ }
+
+ /* Initialze temporary scratch pointer */
+ pScr1 = pScratch1;
+
+ /* Assuming scratch1 buffer is aligned by 32-bit */
+ /* Fill (srcBLen - 1U) zeros in scratch1 buffer */
+ arm_fill_q15(0, pScr1, (srcBLen - 1U));
+
+ /* Update temporary scratch pointer */
+ pScr1 += (srcBLen - 1U);
+
+ /* Copy bigger length sequence(srcALen) samples in scratch1 buffer */
+
+ /* Copy (srcALen) samples in scratch buffer */
+ arm_copy_q15(pIn1, pScr1, srcALen);
+
+ /* Update pointers */
+ pScr1 += srcALen;
+
+
+ /* Fill (srcBLen - 1U) zeros at end of scratch buffer */
+ arm_fill_q15(0, pScr1, (srcBLen - 1U));
+
+ /* Update pointer */
+ pScr1 += (srcBLen - 1U);
+
+ /* Temporary pointer for scratch2 */
+ py = pScratch2;
+
+
+ /* Initialization of pIn2 pointer */
+ pIn2 = py;
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ blkCnt = (srcALen + srcBLen - 1U) >> 2;
+
+ while (blkCnt > 0)
+ {
+ /* Initialze temporary scratch pointer as scratch1 */
+ pScr1 = pScratch1;
+
+ /* Clear Accumlators */
+ acc0 = 0;
+ acc1 = 0;
+ acc2 = 0;
+ acc3 = 0;
+
+ /* Read two samples from scratch1 buffer */
+ x1 = read_q15x2_ia (&pScr1);
+
+ /* Read next two samples from scratch1 buffer */
+ x2 = read_q15x2_ia (&pScr1);
+
+ tapCnt = (srcBLen) >> 2U;
+
+ while (tapCnt > 0U)
+ {
+
+ /* Read four samples from smaller buffer */
+ y1 = read_q15x2_ia ((q15_t **) &pIn2);
+ y2 = read_q15x2_ia ((q15_t **) &pIn2);
+
+ /* multiply and accumlate */
+ acc0 = __SMLAD(x1, y1, acc0);
+ acc2 = __SMLAD(x2, y1, acc2);
+
+ /* pack input data */
+#ifndef ARM_MATH_BIG_ENDIAN
+ x3 = __PKHBT(x2, x1, 0);
+#else
+ x3 = __PKHBT(x1, x2, 0);
+#endif
+
+ /* multiply and accumlate */
+ acc1 = __SMLADX(x3, y1, acc1);
+
+ /* Read next two samples from scratch1 buffer */
+ x1 = read_q15x2_ia (&pScr1);
+
+ /* multiply and accumlate */
+ acc0 = __SMLAD(x2, y2, acc0);
+ acc2 = __SMLAD(x1, y2, acc2);
+
+ /* pack input data */
+#ifndef ARM_MATH_BIG_ENDIAN
+ x3 = __PKHBT(x1, x2, 0);
+#else
+ x3 = __PKHBT(x2, x1, 0);
+#endif
+
+ acc3 = __SMLADX(x3, y1, acc3);
+ acc1 = __SMLADX(x3, y2, acc1);
+
+ x2 = read_q15x2_ia (&pScr1);
+
+#ifndef ARM_MATH_BIG_ENDIAN
+ x3 = __PKHBT(x2, x1, 0);
+#else
+ x3 = __PKHBT(x1, x2, 0);
+#endif
+
+ acc3 = __SMLADX(x3, y2, acc3);
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ /* Update scratch pointer for remaining samples of smaller length sequence */
+ pScr1 -= 4U;
+
+ /* apply same above for remaining samples of smaller length sequence */
+ tapCnt = (srcBLen) & 3U;
+
+ while (tapCnt > 0U)
+ {
+ /* accumlate the results */
+ acc0 += (*pScr1++ * *pIn2);
+ acc1 += (*pScr1++ * *pIn2);
+ acc2 += (*pScr1++ * *pIn2);
+ acc3 += (*pScr1++ * *pIn2++);
+
+ pScr1 -= 3U;
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ blkCnt--;
+
+ /* Store the results in the accumulators in the destination buffer. */
+#ifndef ARM_MATH_BIG_ENDIAN
+ write_q15x2_ia (&pOut, __PKHBT(__SSAT((acc0 >> 15), 16), __SSAT((acc1 >> 15), 16), 16));
+ write_q15x2_ia (&pOut, __PKHBT(__SSAT((acc2 >> 15), 16), __SSAT((acc3 >> 15), 16), 16));
+#else
+ write_q15x2_ia (&pOut, __PKHBT(__SSAT((acc1 >> 15), 16), __SSAT((acc0 >> 15), 16), 16));
+ write_q15x2_ia (&pOut, __PKHBT(__SSAT((acc3 >> 15), 16), __SSAT((acc2 >> 15), 16), 16));
+#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
+
+ /* Initialization of inputB pointer */
+ pIn2 = py;
+
+ pScratch1 += 4U;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ blkCnt = (srcALen + srcBLen - 1U) & 0x3;
+
+#else
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = (srcALen + srcBLen - 1U);
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ /* Calculate convolution for remaining samples of Bigger length sequence */
+ while (blkCnt > 0)
+ {
+ /* Initialze temporary scratch pointer as scratch1 */
+ pScr1 = pScratch1;
+
+ /* Clear Accumlators */
+ acc0 = 0;
+
+ tapCnt = (srcBLen) >> 1U;
+
+ while (tapCnt > 0U)
+ {
+
+ /* Read next two samples from scratch1 buffer */
+ acc0 += (*pScr1++ * *pIn2++);
+ acc0 += (*pScr1++ * *pIn2++);
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ tapCnt = (srcBLen) & 1U;
+
+ /* apply same above for remaining samples of smaller length sequence */
+ while (tapCnt > 0U)
+ {
+
+ /* accumlate the results */
+ acc0 += (*pScr1++ * *pIn2++);
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ blkCnt--;
+
+ /* The result is in 2.30 format. Convert to 1.15 with saturation.
+ Then store the output in the destination buffer. */
+ *pOut++ = (q15_t) (__SSAT((acc0 >> 15), 16));
+
+ /* Initialization of inputB pointer */
+ pIn2 = py;
+
+ pScratch1 += 1U;
+ }
+
+}
+
+/**
+ @} end of Conv group
+ */
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