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Diffstat (limited to 'platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_opt_q15.c')
| -rw-r--r-- | platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_opt_q15.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_opt_q15.c b/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_opt_q15.c new file mode 100644 index 0000000..8ca20d4 --- /dev/null +++ b/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_correlate_opt_q15.c @@ -0,0 +1,513 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 12. March 2014 +* $Revision: V1.4.4 +* +* Project: CMSIS DSP Library +* Title: arm_correlate_opt_q15.c +* +* Description: Correlation of Q15 sequences. +* +* 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 Corr + * @{ + */ + +/** + * @brief Correlation of Q15 sequences. + * @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 2 * max(srcALen, srcBLen) - 1. + * @param[in] *pScratch points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2. + * @return none. + * + * \par Restrictions + * If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE + * In this case input, output, scratch buffers should be aligned by 32-bit + * + * @details + * <b>Scaling and Overflow Behavior:</b> + * + * \par + * The function is implemented using a 64-bit internal accumulator. + * Both inputs are in 1.15 format and multiplications yield a 2.30 result. + * The 2.30 intermediate results are accumulated in a 64-bit accumulator in 34.30 format. + * This approach provides 33 guard bits and there is no risk of overflow. + * The 34.30 result is then truncated to 34.15 format by discarding the low 15 bits and then saturated to 1.15 format. + * + * \par + * Refer to <code>arm_correlate_fast_q15()</code> for a faster but less precise version of this function for Cortex-M3 and Cortex-M4. + * + * + */ + + +void arm_correlate_opt_q15( + q15_t * pSrcA, + uint32_t srcALen, + q15_t * pSrcB, + uint32_t srcBLen, + q15_t * pDst, + q15_t * pScratch) +{ + q15_t *pIn1; /* inputA pointer */ + q15_t *pIn2; /* inputB pointer */ + q63_t acc0, acc1, acc2, acc3; /* Accumulators */ + q15_t *py; /* Intermediate inputB pointer */ + q31_t x1, x2, x3; /* temporary variables for holding input1 and input2 values */ + uint32_t j, blkCnt, outBlockSize; /* loop counter */ + int32_t inc = 1; /* output pointer increment */ + uint32_t tapCnt; + q31_t y1, y2; + q15_t *pScr; /* Intermediate pointers */ + q15_t *pOut = pDst; /* output pointer */ +#ifdef UNALIGNED_SUPPORT_DISABLE + + q15_t a, b; + +#endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ + + /* 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 */ + /* But CORR(x, y) is reverse of CORR(y, x) */ + /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */ + /* and the destination pointer modifier, inc is set to -1 */ + /* If srcALen > srcBLen, zero pad has to be done to srcB to make the two inputs of same length */ + /* But to improve the performance, + * we include zeroes in the output instead of zero padding either of the the inputs*/ + /* If srcALen > srcBLen, + * (srcALen - srcBLen) zeroes has to included in the starting of the output buffer */ + /* If srcALen < srcBLen, + * (srcALen - srcBLen) zeroes has to included in the ending of the output buffer */ + if(srcALen >= srcBLen) + { + /* Initialization of inputA pointer */ + pIn1 = (pSrcA); + + /* Initialization of inputB pointer */ + pIn2 = (pSrcB); + + /* Number of output samples is calculated */ + outBlockSize = (2u * srcALen) - 1u; + + /* When srcALen > srcBLen, zero padding is done to srcB + * to make their lengths equal. + * Instead, (outBlockSize - (srcALen + srcBLen - 1)) + * number of output samples are made zero */ + j = outBlockSize - (srcALen + (srcBLen - 1u)); + + /* Updating the pointer position to non zero value */ + pOut += j; + + } + 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; + + /* CORR(x, y) = Reverse order(CORR(y, x)) */ + /* Hence set the destination pointer to point to the last output sample */ + pOut = pDst + ((srcALen + srcBLen) - 2u); + + /* Destination address modifier is set to -1 */ + inc = -1; + + } + + pScr = pScratch; + + /* Fill (srcBLen - 1u) zeros in scratch buffer */ + arm_fill_q15(0, pScr, (srcBLen - 1u)); + + /* Update temporary scratch pointer */ + pScr += (srcBLen - 1u); + +#ifndef UNALIGNED_SUPPORT_DISABLE + + /* Copy (srcALen) samples in scratch buffer */ + arm_copy_q15(pIn1, pScr, srcALen); + + /* Update pointers */ + //pIn1 += srcALen; + pScr += srcALen; + +#else + + /* Apply loop unrolling and do 4 Copies simultaneously. */ + j = srcALen >> 2u; + + /* First part of the processing with loop unrolling copies 4 data points at a time. + ** a second loop below copies for the remaining 1 to 3 samples. */ + while(j > 0u) + { + /* copy second buffer in reversal manner */ + *pScr++ = *pIn1++; + *pScr++ = *pIn1++; + *pScr++ = *pIn1++; + *pScr++ = *pIn1++; + + /* Decrement the loop counter */ + j--; + } + + /* If the count is not a multiple of 4, copy remaining samples here. + ** No loop unrolling is used. */ + j = srcALen % 0x4u; + + while(j > 0u) + { + /* copy second buffer in reversal manner for remaining samples */ + *pScr++ = *pIn1++; + + /* Decrement the loop counter */ + j--; + } + +#endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ + +#ifndef UNALIGNED_SUPPORT_DISABLE + + /* Fill (srcBLen - 1u) zeros at end of scratch buffer */ + arm_fill_q15(0, pScr, (srcBLen - 1u)); + + /* Update pointer */ + pScr += (srcBLen - 1u); + +#else + +/* Apply loop unrolling and do 4 Copies simultaneously. */ + j = (srcBLen - 1u) >> 2u; + + /* First part of the processing with loop unrolling copies 4 data points at a time. + ** a second loop below copies for the remaining 1 to 3 samples. */ + while(j > 0u) + { + /* copy second buffer in reversal manner */ + *pScr++ = 0; + *pScr++ = 0; + *pScr++ = 0; + *pScr++ = 0; + + /* Decrement the loop counter */ + j--; + } + + /* If the count is not a multiple of 4, copy remaining samples here. + ** No loop unrolling is used. */ + j = (srcBLen - 1u) % 0x4u; + + while(j > 0u) + { + /* copy second buffer in reversal manner for remaining samples */ + *pScr++ = 0; + + /* Decrement the loop counter */ + j--; + } + +#endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ + + /* Temporary pointer for scratch2 */ + py = pIn2; + + + /* Actual correlation process starts here */ + blkCnt = (srcALen + srcBLen - 1u) >> 2; + + while(blkCnt > 0) + { + /* Initialze temporary scratch pointer as scratch1 */ + pScr = pScratch; + + /* Clear Accumlators */ + acc0 = 0; + acc1 = 0; + acc2 = 0; + acc3 = 0; + + /* Read four samples from scratch1 buffer */ + x1 = *__SIMD32(pScr)++; + + /* Read next four samples from scratch1 buffer */ + x2 = *__SIMD32(pScr)++; + + tapCnt = (srcBLen) >> 2u; + + while(tapCnt > 0u) + { + +#ifndef UNALIGNED_SUPPORT_DISABLE + + /* Read four samples from smaller buffer */ + y1 = _SIMD32_OFFSET(pIn2); + y2 = _SIMD32_OFFSET(pIn2 + 2u); + + acc0 = __SMLALD(x1, y1, acc0); + + acc2 = __SMLALD(x2, y1, acc2); + +#ifndef ARM_MATH_BIG_ENDIAN + x3 = __PKHBT(x2, x1, 0); +#else + x3 = __PKHBT(x1, x2, 0); +#endif + + acc1 = __SMLALDX(x3, y1, acc1); + + x1 = _SIMD32_OFFSET(pScr); + + acc0 = __SMLALD(x2, y2, acc0); + + acc2 = __SMLALD(x1, y2, acc2); + +#ifndef ARM_MATH_BIG_ENDIAN + x3 = __PKHBT(x1, x2, 0); +#else + x3 = __PKHBT(x2, x1, 0); +#endif + + acc3 = __SMLALDX(x3, y1, acc3); + + acc1 = __SMLALDX(x3, y2, acc1); + + x2 = _SIMD32_OFFSET(pScr + 2u); + +#ifndef ARM_MATH_BIG_ENDIAN + x3 = __PKHBT(x2, x1, 0); +#else + x3 = __PKHBT(x1, x2, 0); +#endif + + acc3 = __SMLALDX(x3, y2, acc3); + +#else + + /* Read four samples from smaller buffer */ + a = *pIn2; + b = *(pIn2 + 1); + +#ifndef ARM_MATH_BIG_ENDIAN + y1 = __PKHBT(a, b, 16); +#else + y1 = __PKHBT(b, a, 16); +#endif + + a = *(pIn2 + 2); + b = *(pIn2 + 3); +#ifndef ARM_MATH_BIG_ENDIAN + y2 = __PKHBT(a, b, 16); +#else + y2 = __PKHBT(b, a, 16); +#endif + + acc0 = __SMLALD(x1, y1, acc0); + + acc2 = __SMLALD(x2, y1, acc2); + +#ifndef ARM_MATH_BIG_ENDIAN + x3 = __PKHBT(x2, x1, 0); +#else + x3 = __PKHBT(x1, x2, 0); +#endif + + acc1 = __SMLALDX(x3, y1, acc1); + + a = *pScr; + b = *(pScr + 1); + +#ifndef ARM_MATH_BIG_ENDIAN + x1 = __PKHBT(a, b, 16); +#else + x1 = __PKHBT(b, a, 16); +#endif + + acc0 = __SMLALD(x2, y2, acc0); + + acc2 = __SMLALD(x1, y2, acc2); + +#ifndef ARM_MATH_BIG_ENDIAN + x3 = __PKHBT(x1, x2, 0); +#else + x3 = __PKHBT(x2, x1, 0); +#endif + + acc3 = __SMLALDX(x3, y1, acc3); + + acc1 = __SMLALDX(x3, y2, acc1); + + a = *(pScr + 2); + b = *(pScr + 3); + +#ifndef ARM_MATH_BIG_ENDIAN + x2 = __PKHBT(a, b, 16); +#else + x2 = __PKHBT(b, a, 16); +#endif + +#ifndef ARM_MATH_BIG_ENDIAN + x3 = __PKHBT(x2, x1, 0); +#else + x3 = __PKHBT(x1, x2, 0); +#endif + + acc3 = __SMLALDX(x3, y2, acc3); + +#endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ + + pIn2 += 4u; + + pScr += 4u; + + + /* Decrement the loop counter */ + tapCnt--; + } + + + + /* Update scratch pointer for remaining samples of smaller length sequence */ + pScr -= 4u; + + + /* apply same above for remaining samples of smaller length sequence */ + tapCnt = (srcBLen) & 3u; + + while(tapCnt > 0u) + { + + /* accumlate the results */ + acc0 += (*pScr++ * *pIn2); + acc1 += (*pScr++ * *pIn2); + acc2 += (*pScr++ * *pIn2); + acc3 += (*pScr++ * *pIn2++); + + pScr -= 3u; + + /* Decrement the loop counter */ + tapCnt--; + } + + blkCnt--; + + + /* Store the results in the accumulators in the destination buffer. */ + *pOut = (__SSAT(acc0 >> 15u, 16)); + pOut += inc; + *pOut = (__SSAT(acc1 >> 15u, 16)); + pOut += inc; + *pOut = (__SSAT(acc2 >> 15u, 16)); + pOut += inc; + *pOut = (__SSAT(acc3 >> 15u, 16)); + pOut += inc; + + /* Initialization of inputB pointer */ + pIn2 = py; + + pScratch += 4u; + + } + + + blkCnt = (srcALen + srcBLen - 1u) & 0x3; + + /* Calculate correlation for remaining samples of Bigger length sequence */ + while(blkCnt > 0) + { + /* Initialze temporary scratch pointer as scratch1 */ + pScr = pScratch; + + /* Clear Accumlators */ + acc0 = 0; + + tapCnt = (srcBLen) >> 1u; + + while(tapCnt > 0u) + { + + acc0 += (*pScr++ * *pIn2++); + acc0 += (*pScr++ * *pIn2++); + + /* Decrement the loop counter */ + tapCnt--; + } + + tapCnt = (srcBLen) & 1u; + + /* apply same above for remaining samples of smaller length sequence */ + while(tapCnt > 0u) + { + + /* accumlate the results */ + acc0 += (*pScr++ * *pIn2++); + + /* Decrement the loop counter */ + tapCnt--; + } + + blkCnt--; + + /* Store the result in the accumulator in the destination buffer. */ + *pOut = (q15_t) (__SSAT((acc0 >> 15), 16)); + + pOut += inc; + + /* Initialization of inputB pointer */ + pIn2 = py; + + pScratch += 1u; + + } + + +} + +/** + * @} end of Corr group + */ |