| /* ---------------------------------------------------------------------- |
| * Project: CMSIS DSP Library |
| * Title: arm_cmplx_mult_cmplx_q15.c |
| * Description: Q15 complex-by-complex multiplication |
| * |
| * $Date: 27. January 2017 |
| * $Revision: V.1.5.1 |
| * |
| * Target Processor: Cortex-M cores |
| * -------------------------------------------------------------------- */ |
| /* |
| * Copyright (C) 2010-2017 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 CmplxByCmplxMult |
| * @{ |
| */ |
| |
| /** |
| * @brief Q15 complex-by-complex multiplication |
| * @param[in] *pSrcA points to the first input vector |
| * @param[in] *pSrcB points to the second input vector |
| * @param[out] *pDst points to the output vector |
| * @param[in] numSamples number of complex samples in each vector |
| * @return none. |
| * |
| * <b>Scaling and Overflow Behavior:</b> |
| * \par |
| * The function implements 1.15 by 1.15 multiplications and finally output is converted into 3.13 format. |
| */ |
| |
| void arm_cmplx_mult_cmplx_q15( |
| q15_t * pSrcA, |
| q15_t * pSrcB, |
| q15_t * pDst, |
| uint32_t numSamples) |
| { |
| q15_t a, b, c, d; /* Temporary variables to store real and imaginary values */ |
| |
| #if defined (ARM_MATH_DSP) |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| uint32_t blkCnt; /* loop counters */ |
| |
| /* loop Unrolling */ |
| blkCnt = numSamples >> 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[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */ |
| /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */ |
| a = *pSrcA++; |
| b = *pSrcA++; |
| c = *pSrcB++; |
| d = *pSrcB++; |
| |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17); |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17); |
| |
| a = *pSrcA++; |
| b = *pSrcA++; |
| c = *pSrcB++; |
| d = *pSrcB++; |
| |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17); |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17); |
| |
| a = *pSrcA++; |
| b = *pSrcA++; |
| c = *pSrcB++; |
| d = *pSrcB++; |
| |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17); |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17); |
| |
| a = *pSrcA++; |
| b = *pSrcA++; |
| c = *pSrcB++; |
| d = *pSrcB++; |
| |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17); |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17); |
| |
| /* Decrement the blockSize loop counter */ |
| blkCnt--; |
| } |
| |
| /* If the blockSize is not a multiple of 4, compute any remaining output samples here. |
| ** No loop unrolling is used. */ |
| blkCnt = numSamples % 0x4U; |
| |
| while (blkCnt > 0U) |
| { |
| /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */ |
| /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */ |
| a = *pSrcA++; |
| b = *pSrcA++; |
| c = *pSrcB++; |
| d = *pSrcB++; |
| |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17); |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17); |
| |
| /* Decrement the blockSize loop counter */ |
| blkCnt--; |
| } |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| while (numSamples > 0U) |
| { |
| /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */ |
| /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */ |
| a = *pSrcA++; |
| b = *pSrcA++; |
| c = *pSrcB++; |
| d = *pSrcB++; |
| |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17); |
| /* store the result in 3.13 format in the destination buffer. */ |
| *pDst++ = |
| (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17); |
| |
| /* Decrement the blockSize loop counter */ |
| numSamples--; |
| } |
| |
| #endif /* #if defined (ARM_MATH_DSP) */ |
| |
| } |
| |
| /** |
| * @} end of CmplxByCmplxMult group |
| */ |