| /* ---------------------------------------------------------------------- |
| * Project: CMSIS DSP Library |
| * Title: arm_cmplx_dot_prod_q31.c |
| * Description: Q31 complex dot product |
| * |
| * $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 groupCmplxMath |
| */ |
| |
| /** |
| @addtogroup cmplx_dot_prod |
| @{ |
| */ |
| |
| /** |
| @brief Q31 complex dot product. |
| @param[in] pSrcA points to the first input vector |
| @param[in] pSrcB points to the second input vector |
| @param[in] numSamples number of samples in each vector |
| @param[out] realResult real part of the result returned here |
| @param[out] imagResult imaginary part of the result returned here |
| @return none |
| |
| @par Scaling and Overflow Behavior |
| The function is implemented using an internal 64-bit accumulator. |
| The intermediate 1.31 by 1.31 multiplications are performed with 64-bit precision and then shifted to 16.48 format. |
| The internal real and imaginary accumulators are in 16.48 format and provide 15 guard bits. |
| Additions are nonsaturating and no overflow will occur as long as <code>numSamples</code> is less than 32768. |
| The return results <code>realResult</code> and <code>imagResult</code> are in 16.48 format. |
| Input down scaling is not required. |
| */ |
| |
| void arm_cmplx_dot_prod_q31( |
| const q31_t * pSrcA, |
| const q31_t * pSrcB, |
| uint32_t numSamples, |
| q63_t * realResult, |
| q63_t * imagResult) |
| { |
| uint32_t blkCnt; /* Loop counter */ |
| q63_t real_sum = 0, imag_sum = 0; /* Temporary result variables */ |
| q31_t a0,b0,c0,d0; |
| |
| #if defined (ARM_MATH_LOOPUNROLL) |
| |
| /* Loop unrolling: Compute 4 outputs at a time */ |
| blkCnt = numSamples >> 2U; |
| |
| while (blkCnt > 0U) |
| { |
| a0 = *pSrcA++; |
| b0 = *pSrcA++; |
| c0 = *pSrcB++; |
| d0 = *pSrcB++; |
| |
| real_sum += ((q63_t)a0 * c0) >> 14; |
| imag_sum += ((q63_t)a0 * d0) >> 14; |
| real_sum -= ((q63_t)b0 * d0) >> 14; |
| imag_sum += ((q63_t)b0 * c0) >> 14; |
| |
| a0 = *pSrcA++; |
| b0 = *pSrcA++; |
| c0 = *pSrcB++; |
| d0 = *pSrcB++; |
| |
| real_sum += ((q63_t)a0 * c0) >> 14; |
| imag_sum += ((q63_t)a0 * d0) >> 14; |
| real_sum -= ((q63_t)b0 * d0) >> 14; |
| imag_sum += ((q63_t)b0 * c0) >> 14; |
| |
| a0 = *pSrcA++; |
| b0 = *pSrcA++; |
| c0 = *pSrcB++; |
| d0 = *pSrcB++; |
| |
| real_sum += ((q63_t)a0 * c0) >> 14; |
| imag_sum += ((q63_t)a0 * d0) >> 14; |
| real_sum -= ((q63_t)b0 * d0) >> 14; |
| imag_sum += ((q63_t)b0 * c0) >> 14; |
| |
| a0 = *pSrcA++; |
| b0 = *pSrcA++; |
| c0 = *pSrcB++; |
| d0 = *pSrcB++; |
| |
| real_sum += ((q63_t)a0 * c0) >> 14; |
| imag_sum += ((q63_t)a0 * d0) >> 14; |
| real_sum -= ((q63_t)b0 * d0) >> 14; |
| imag_sum += ((q63_t)b0 * c0) >> 14; |
| |
| /* Decrement loop counter */ |
| blkCnt--; |
| } |
| |
| /* Loop unrolling: Compute remaining outputs */ |
| blkCnt = numSamples % 0x4U; |
| |
| #else |
| |
| /* Initialize blkCnt with number of samples */ |
| blkCnt = numSamples; |
| |
| #endif /* #if defined (ARM_MATH_LOOPUNROLL) */ |
| |
| while (blkCnt > 0U) |
| { |
| a0 = *pSrcA++; |
| b0 = *pSrcA++; |
| c0 = *pSrcB++; |
| d0 = *pSrcB++; |
| |
| real_sum += ((q63_t)a0 * c0) >> 14; |
| imag_sum += ((q63_t)a0 * d0) >> 14; |
| real_sum -= ((q63_t)b0 * d0) >> 14; |
| imag_sum += ((q63_t)b0 * c0) >> 14; |
| |
| /* Decrement loop counter */ |
| blkCnt--; |
| } |
| |
| /* Store real and imaginary result in 16.48 format */ |
| *realResult = real_sum; |
| *imagResult = imag_sum; |
| } |
| |
| /** |
| @} end of cmplx_dot_prod group |
| */ |