| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
| * |
| * $Date: 19. March 2015 |
| * $Revision: V.1.4.5 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_dot_prod_q31.c |
| * |
| * Description: Q31 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 Q31 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. |
| * |
| * <b>Scaling and Overflow Behavior:</b> |
| * \par |
| * The intermediate multiplications are in 1.31 x 1.31 = 2.62 format and these |
| * are truncated to 2.48 format by discarding the lower 14 bits. |
| * The 2.48 result is then added without saturation to a 64-bit accumulator in 16.48 format. |
| * There are 15 guard bits in the accumulator and there is no risk of overflow as long as |
| * the length of the vectors is less than 2^16 elements. |
| * The return result is in 16.48 format. |
| */ |
| |
| void arm_dot_prod_q31( |
| q31_t * pSrcA, |
| q31_t * pSrcB, |
| uint32_t blockSize, |
| q63_t * result) |
| { |
| q63_t sum = 0; /* Temporary result storage */ |
| uint32_t blkCnt; /* loop counter */ |
| |
| |
| #ifndef ARM_MATH_CM0_FAMILY |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| q31_t inA1, inA2, inA3, inA4; |
| q31_t inB1, inB2, inB3, inB4; |
| |
| /*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) |
| { |
| /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */ |
| /* Calculate dot product and then store the result in a temporary buffer. */ |
| inA1 = *pSrcA++; |
| inA2 = *pSrcA++; |
| inA3 = *pSrcA++; |
| inA4 = *pSrcA++; |
| inB1 = *pSrcB++; |
| inB2 = *pSrcB++; |
| inB3 = *pSrcB++; |
| inB4 = *pSrcB++; |
| |
| sum += ((q63_t) inA1 * inB1) >> 14u; |
| sum += ((q63_t) inA2 * inB2) >> 14u; |
| sum += ((q63_t) inA3 * inB3) >> 14u; |
| sum += ((q63_t) inA4 * inB4) >> 14u; |
| |
| /* 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; |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| /* Initialize blkCnt with number of samples */ |
| blkCnt = blockSize; |
| |
| #endif /* #ifndef ARM_MATH_CM0_FAMILY */ |
| |
| |
| while(blkCnt > 0u) |
| { |
| /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */ |
| /* Calculate dot product and then store the result in a temporary buffer. */ |
| sum += ((q63_t) * pSrcA++ * *pSrcB++) >> 14u; |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| /* Store the result in the destination buffer in 16.48 format */ |
| *result = sum; |
| } |
| |
| /** |
| * @} end of dot_prod group |
| */ |