/* ---------------------------------------------------------------------- * Copyright (C) 2010-2014 ARM Limited. All rights reserved. * * $Date: 12. March 2014 * $Revision: V1.4.4 * * Project: CMSIS DSP Library * Title: arm_dot_prod_q7.c * * Description: Q7 dot product. * * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 * * 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 groupMath */ /** * @addtogroup dot_prod * @{ */ /** * @brief Dot product of Q7 vectors. * @param[in] *pSrcA points to the first input vector * @param[in] *pSrcB points to the second input vector * @param[in] blockSize number of samples in each vector * @param[out] *result output result returned here * @return none. * * Scaling and Overflow Behavior: * \par * The intermediate multiplications are in 1.7 x 1.7 = 2.14 format and these * results are added to an accumulator in 18.14 format. * Nonsaturating additions are used and there is no danger of wrap around as long as * the vectors are less than 2^18 elements long. * The return result is in 18.14 format. */ void arm_dot_prod_q7( q7_t * pSrcA, q7_t * pSrcB, uint32_t blockSize, q31_t * result) { uint32_t blkCnt; /* loop counter */ q31_t sum = 0; /* Temporary variables to store output */ #ifndef ARM_MATH_CM0_FAMILY /* Run the below code for Cortex-M4 and Cortex-M3 */ q31_t input1, input2; /* Temporary variables to store input */ q31_t inA1, inA2, inB1, inB2; /* Temporary variables to store input */ /*loop Unrolling */ blkCnt = blockSize >> 2u; /* 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) { /* read 4 samples at a time from sourceA */ input1 = *__SIMD32(pSrcA)++; /* read 4 samples at a time from sourceB */ input2 = *__SIMD32(pSrcB)++; /* extract two q7_t samples to q15_t samples */ inA1 = __SXTB16(__ROR(input1, 8)); /* extract reminaing two samples */ inA2 = __SXTB16(input1); /* extract two q7_t samples to q15_t samples */ inB1 = __SXTB16(__ROR(input2, 8)); /* extract reminaing two samples */ inB2 = __SXTB16(input2); /* multiply and accumulate two samples at a time */ sum = __SMLAD(inA1, inB1, sum); sum = __SMLAD(inA2, inB2, sum); /* Decrement the 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 % 0x4u; while(blkCnt > 0u) { /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */ /* Dot product and then store the results in a temporary buffer. */ sum = __SMLAD(*pSrcA++, *pSrcB++, sum); /* Decrement the loop counter */ blkCnt--; } #else /* Run the below code for Cortex-M0 */ /* Initialize blkCnt with number of samples */ blkCnt = blockSize; while(blkCnt > 0u) { /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */ /* Dot product and then store the results in a temporary buffer. */ sum += (q31_t) ((q15_t) * pSrcA++ * *pSrcB++); /* Decrement the loop counter */ blkCnt--; } #endif /* #ifndef ARM_MATH_CM0_FAMILY */ /* Store the result in the destination buffer in 18.14 format */ *result = sum; } /** * @} end of dot_prod group */