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Rev	Author	Line No.	Line
2	mjames	1	/* ----------------------------------------------------------------------
		2	* Project: CMSIS DSP Library
		3	* Title: arm_cmplx_dot_prod_f32.c
		4	* Description: Floating-point complex dot product
		5	*
		6	* $Date: 27. January 2017
		7	* $Revision: V.1.5.1
		8	*
		9	* Target Processor: Cortex-M cores
		10	* -------------------------------------------------------------------- */
		11	/*
		12	* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
		13	*
		14	* SPDX-License-Identifier: Apache-2.0
		15	*
		16	* Licensed under the Apache License, Version 2.0 (the License); you may
		17	* not use this file except in compliance with the License.
		18	* You may obtain a copy of the License at
		19	*
		20	* www.apache.org/licenses/LICENSE-2.0
		21	*
		22	* Unless required by applicable law or agreed to in writing, software
		23	* distributed under the License is distributed on an AS IS BASIS, WITHOUT
		24	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		25	* See the License for the specific language governing permissions and
		26	* limitations under the License.
		27	*/
		28
		29	#include "arm_math.h"
		30
		31	/**
		32	* @ingroup groupCmplxMath
		33	*/
		34
		35	/**
		36	* @defgroup cmplx_dot_prod Complex Dot Product
		37	*
		38	* Computes the dot product of two complex vectors.
		39	* The vectors are multiplied element-by-element and then summed.
		40	*
		41	* The <code>pSrcA</code> points to the first complex input vector and
		42	* <code>pSrcB</code> points to the second complex input vector.
		43	* <code>numSamples</code> specifies the number of complex samples
		44	* and the data in each array is stored in an interleaved fashion
		45	* (real, imag, real, imag, ...).
		46	* Each array has a total of <code>2*numSamples</code> values.
		47	*
		48	* The underlying algorithm is used:
		49	* <pre>
		50	* realResult=0;
		51	* imagResult=0;
		52	* for(n=0; n<numSamples; n++) {
		53	* realResult += pSrcA[(2n)+0]pSrcB[(2n)+0] - pSrcA[(2n)+1]pSrcB[(2n)+1];
		54	* imagResult += pSrcA[(2n)+0]pSrcB[(2n)+1] + pSrcA[(2n)+1]pSrcB[(2n)+0];
		55	* }
		56	* </pre>
		57	*
		58	* There are separate functions for floating-point, Q15, and Q31 data types.
		59	*/
		60
		61	/**
		62	* @addtogroup cmplx_dot_prod
		63	* @{
		64	*/
		65
		66	/**
		67	* @brief Floating-point complex dot product
		68	* @param *pSrcA points to the first input vector
		69	* @param *pSrcB points to the second input vector
		70	* @param numSamples number of complex samples in each vector
		71	* @param *realResult real part of the result returned here
		72	* @param *imagResult imaginary part of the result returned here
		73	* @return none.
		74	*/
		75
		76	void arm_cmplx_dot_prod_f32(
		77	float32_t * pSrcA,
		78	float32_t * pSrcB,
		79	uint32_t numSamples,
		80	float32_t * realResult,
		81	float32_t * imagResult)
		82	{
		83	float32_t real_sum = 0.0f, imag_sum = 0.0f; /* Temporary result storage */
		84	float32_t a0,b0,c0,d0;
		85
		86	#if defined (ARM_MATH_DSP)
		87
		88	/* Run the below code for Cortex-M4 and Cortex-M3 */
		89	uint32_t blkCnt; /* loop counter */
		90
		91	/loop Unrolling /
		92	blkCnt = numSamples >> 2U;
		93
		94	/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
		95	** a second loop below computes the remaining 1 to 3 samples. */
		96	while (blkCnt > 0U)
		97	{
		98	a0 = *pSrcA++;
		99	b0 = *pSrcA++;
		100	c0 = *pSrcB++;
		101	d0 = *pSrcB++;
		102
		103	real_sum += a0 * c0;
		104	imag_sum += a0 * d0;
		105	real_sum -= b0 * d0;
		106	imag_sum += b0 * c0;
		107
		108	a0 = *pSrcA++;
		109	b0 = *pSrcA++;
		110	c0 = *pSrcB++;
		111	d0 = *pSrcB++;
		112
		113	real_sum += a0 * c0;
		114	imag_sum += a0 * d0;
		115	real_sum -= b0 * d0;
		116	imag_sum += b0 * c0;
		117
		118	a0 = *pSrcA++;
		119	b0 = *pSrcA++;
		120	c0 = *pSrcB++;
		121	d0 = *pSrcB++;
		122
		123	real_sum += a0 * c0;
		124	imag_sum += a0 * d0;
		125	real_sum -= b0 * d0;
		126	imag_sum += b0 * c0;
		127
		128	a0 = *pSrcA++;
		129	b0 = *pSrcA++;
		130	c0 = *pSrcB++;
		131	d0 = *pSrcB++;
		132
		133	real_sum += a0 * c0;
		134	imag_sum += a0 * d0;
		135	real_sum -= b0 * d0;
		136	imag_sum += b0 * c0;
		137
		138	/* Decrement the loop counter */
		139	blkCnt--;
		140	}
		141
		142	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		143	** No loop unrolling is used. */
		144	blkCnt = numSamples & 0x3U;
		145
		146	while (blkCnt > 0U)
		147	{
		148	a0 = *pSrcA++;
		149	b0 = *pSrcA++;
		150	c0 = *pSrcB++;
		151	d0 = *pSrcB++;
		152
		153	real_sum += a0 * c0;
		154	imag_sum += a0 * d0;
		155	real_sum -= b0 * d0;
		156	imag_sum += b0 * c0;
		157
		158	/* Decrement the loop counter */
		159	blkCnt--;
		160	}
		161
		162	#else
		163
		164	/* Run the below code for Cortex-M0 */
		165
		166	while (numSamples > 0U)
		167	{
		168	a0 = *pSrcA++;
		169	b0 = *pSrcA++;
		170	c0 = *pSrcB++;
		171	d0 = *pSrcB++;
		172
		173	real_sum += a0 * c0;
		174	imag_sum += a0 * d0;
		175	real_sum -= b0 * d0;
		176	imag_sum += b0 * c0;
		177
		178	/* Decrement the loop counter */
		179	numSamples--;
		180	}
		181
		182	#endif /* #if defined (ARM_MATH_DSP) */
		183
		184	/* Store the real and imaginary results in the destination buffers */
		185	*realResult = real_sum;
		186	*imagResult = imag_sum;
		187	}
		188
		189	/**
		190	* @} end of cmplx_dot_prod group
		191	*/

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