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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_q31.c
		9	*
		10	* Description: Q31 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	/**
		54	* @brief Q31 complex magnitude squared
		55	* @param *pSrc points to the complex input vector
		56	* @param *pDst points to the real output vector
		57	* @param numSamples number of complex samples in the input vector
		58	* @return none.
		59	*
		60	* <b>Scaling and Overflow Behavior:</b>
		61	* \par
		62	* The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format.
		63	* Input down scaling is not required.
		64	*/
		65
		66	void arm_cmplx_mag_squared_q31(
		67	q31_t * pSrc,
		68	q31_t * pDst,
		69	uint32_t numSamples)
		70	{
		71	q31_t real, imag; /* Temporary variables to store real and imaginary values */
		72	q31_t acc0, acc1; /* Accumulators */
		73
		74	#ifndef ARM_MATH_CM0_FAMILY
		75
		76	/* Run the below code for Cortex-M4 and Cortex-M3 */
		77	uint32_t blkCnt; /* loop counter */
		78
		79	/* loop Unrolling */
		80	blkCnt = numSamples >> 2u;
		81
		82	/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
		83	** a second loop below computes the remaining 1 to 3 samples. */
		84	while(blkCnt > 0u)
		85	{
		86	/* C[0] = (A[0] * A[0] + A[1] * A[1]) */
		87	real = *pSrc++;
		88	imag = *pSrc++;
		89	acc0 = (q31_t) (((q63_t) real * real) >> 33);
		90	acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
		91	/* store the result in 3.29 format in the destination buffer. */
		92	*pDst++ = acc0 + acc1;
		93
		94	real = *pSrc++;
		95	imag = *pSrc++;
		96	acc0 = (q31_t) (((q63_t) real * real) >> 33);
		97	acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
		98	/* store the result in 3.29 format in the destination buffer. */
		99	*pDst++ = acc0 + acc1;
		100
		101	real = *pSrc++;
		102	imag = *pSrc++;
		103	acc0 = (q31_t) (((q63_t) real * real) >> 33);
		104	acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
		105	/* store the result in 3.29 format in the destination buffer. */
		106	*pDst++ = acc0 + acc1;
		107
		108	real = *pSrc++;
		109	imag = *pSrc++;
		110	acc0 = (q31_t) (((q63_t) real * real) >> 33);
		111	acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
		112	/* store the result in 3.29 format in the destination buffer. */
		113	*pDst++ = acc0 + acc1;
		114
		115	/* Decrement the loop counter */
		116	blkCnt--;
		117	}
		118
		119	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		120	** No loop unrolling is used. */
		121	blkCnt = numSamples % 0x4u;
		122
		123	while(blkCnt > 0u)
		124	{
		125	/* C[0] = (A[0] * A[0] + A[1] * A[1]) */
		126	real = *pSrc++;
		127	imag = *pSrc++;
		128	acc0 = (q31_t) (((q63_t) real * real) >> 33);
		129	acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
		130	/* store the result in 3.29 format in the destination buffer. */
		131	*pDst++ = acc0 + acc1;
		132
		133	/* Decrement the loop counter */
		134	blkCnt--;
		135	}
		136
		137	#else
		138
		139	/* Run the below code for Cortex-M0 */
		140
		141	while(numSamples > 0u)
		142	{
		143	/* out = ((real * real) + (imag * imag)) */
		144	real = *pSrc++;
		145	imag = *pSrc++;
		146	acc0 = (q31_t) (((q63_t) real * real) >> 33);
		147	acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
		148	/* store the result in 3.29 format in the destination buffer. */
		149	*pDst++ = acc0 + acc1;
		150
		151	/* Decrement the loop counter */
		152	numSamples--;
		153	}
		154
		155	#endif /* #ifndef ARM_MATH_CM0_FAMILY */
		156
		157	}
		158
		159	/**
		160	* @} end of cmplx_mag_squared group
		161	*/

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