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Rev	Author	Line No.	Line
2	mjames	1	/* ----------------------------------------------------------------------
		2	* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
		3	*
		4	* $Date: 19. March 2015
		5	* $Revision: V.1.4.5
		6	*
		7	* Project: CMSIS DSP Library
		8	* Title: arm_cmplx_mag_squared_q15.c
		9	*
		10	* Description: Q15 complex magnitude squared.
		11	*
		12	* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
		13	*
		14	* Redistribution and use in source and binary forms, with or without
		15	* modification, are permitted provided that the following conditions
		16	* are met:
		17	* - Redistributions of source code must retain the above copyright
		18	* notice, this list of conditions and the following disclaimer.
		19	* - Redistributions in binary form must reproduce the above copyright
		20	* notice, this list of conditions and the following disclaimer in
		21	* the documentation and/or other materials provided with the
		22	* distribution.
		23	* - Neither the name of ARM LIMITED nor the names of its contributors
		24	* may be used to endorse or promote products derived from this
		25	* software without specific prior written permission.
		26	*
		27	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
		28	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
		29	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
		30	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
		31	* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
		32	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
		33	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
		34	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
		35	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
		36	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
		37	* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
		38	* POSSIBILITY OF SUCH DAMAGE.
		39	* ---------------------------------------------------------------------------- */
		40
		41	#include "arm_math.h"
		42
		43	/**
		44	* @ingroup groupCmplxMath
		45	*/
		46
		47	/**
		48	* @addtogroup cmplx_mag_squared
		49	* @{
		50	*/
		51
		52	/**
		53	* @brief Q15 complex magnitude squared
		54	* @param *pSrc points to the complex input vector
		55	* @param *pDst points to the real output vector
		56	* @param numSamples number of complex samples in the input vector
		57	* @return none.
		58	*
		59	* <b>Scaling and Overflow Behavior:</b>
		60	* \par
		61	* The function implements 1.15 by 1.15 multiplications and finally output is converted into 3.13 format.
		62	*/
		63
		64	void arm_cmplx_mag_squared_q15(
		65	q15_t * pSrc,
		66	q15_t * pDst,
		67	uint32_t numSamples)
		68	{
		69	q31_t acc0, acc1; /* Accumulators */
		70
		71	#ifndef ARM_MATH_CM0_FAMILY
		72
		73	/* Run the below code for Cortex-M4 and Cortex-M3 */
		74	uint32_t blkCnt; /* loop counter */
		75	q31_t in1, in2, in3, in4;
		76	q31_t acc2, acc3;
		77
		78	/loop Unrolling /
		79	blkCnt = numSamples >> 2u;
		80
		81	/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
		82	** a second loop below computes the remaining 1 to 3 samples. */
		83	while(blkCnt > 0u)
		84	{
		85	/* C[0] = (A[0] * A[0] + A[1] * A[1]) */
		86	in1 = *__SIMD32(pSrc)++;
		87	in2 = *__SIMD32(pSrc)++;
		88	in3 = *__SIMD32(pSrc)++;
		89	in4 = *__SIMD32(pSrc)++;
		90
		91	acc0 = __SMUAD(in1, in1);
		92	acc1 = __SMUAD(in2, in2);
		93	acc2 = __SMUAD(in3, in3);
		94	acc3 = __SMUAD(in4, in4);
		95
		96	/* store the result in 3.13 format in the destination buffer. */
		97	*pDst++ = (q15_t) (acc0 >> 17);
		98	*pDst++ = (q15_t) (acc1 >> 17);
		99	*pDst++ = (q15_t) (acc2 >> 17);
		100	*pDst++ = (q15_t) (acc3 >> 17);
		101
		102	/* Decrement the loop counter */
		103	blkCnt--;
		104	}
		105
		106	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		107	** No loop unrolling is used. */
		108	blkCnt = numSamples % 0x4u;
		109
		110	while(blkCnt > 0u)
		111	{
		112	/* C[0] = (A[0] * A[0] + A[1] * A[1]) */
		113	in1 = *__SIMD32(pSrc)++;
		114	acc0 = __SMUAD(in1, in1);
		115
		116	/* store the result in 3.13 format in the destination buffer. */
		117	*pDst++ = (q15_t) (acc0 >> 17);
		118
		119	/* Decrement the loop counter */
		120	blkCnt--;
		121	}
		122
		123	#else
		124
		125	/* Run the below code for Cortex-M0 */
		126	q15_t real, imag; /* Temporary variables to store real and imaginary values */
		127
		128	while(numSamples > 0u)
		129	{
		130	/* out = ((real * real) + (imag * imag)) */
		131	real = *pSrc++;
		132	imag = *pSrc++;
		133	acc0 = (real * real);
		134	acc1 = (imag * imag);
		135	/* store the result in 3.13 format in the destination buffer. */
		136	*pDst++ = (q15_t) (((q63_t) acc0 + acc1) >> 17);
		137
		138	/* Decrement the loop counter */
		139	numSamples--;
		140	}
		141
		142	#endif /* #ifndef ARM_MATH_CM0_FAMILY */
		143
		144	}
		145
		146	/**
		147	* @} end of cmplx_mag_squared group
		148	*/

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