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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_q15.c
		9	*
		10	* Description: Q15 complex magnitude.
		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
		49	* @{
		50	*/
		51
		52
		53	/**
		54	* @brief Q15 complex magnitude
		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 1.15 by 1.15 multiplications and finally output is converted into 2.14 format.
		63	*/
		64
		65	void arm_cmplx_mag_q15(
		66	q15_t * pSrc,
		67	q15_t * pDst,
		68	uint32_t numSamples)
		69	{
		70	q31_t acc0, acc1; /* Accumulators */
		71
		72	#ifndef ARM_MATH_CM0_FAMILY
		73
		74	/* Run the below code for Cortex-M4 and Cortex-M3 */
		75	uint32_t blkCnt; /* loop counter */
		76	q31_t in1, in2, in3, in4;
		77	q31_t acc2, acc3;
		78
		79
		80	/loop Unrolling /
		81	blkCnt = numSamples >> 2u;
		82
		83	/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
		84	** a second loop below computes the remaining 1 to 3 samples. */
		85	while(blkCnt > 0u)
		86	{
		87
		88	/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
		89	in1 = *__SIMD32(pSrc)++;
		90	in2 = *__SIMD32(pSrc)++;
		91	in3 = *__SIMD32(pSrc)++;
		92	in4 = *__SIMD32(pSrc)++;
		93
		94	acc0 = __SMUAD(in1, in1);
		95	acc1 = __SMUAD(in2, in2);
		96	acc2 = __SMUAD(in3, in3);
		97	acc3 = __SMUAD(in4, in4);
		98
		99	/* store the result in 2.14 format in the destination buffer. */
		100	arm_sqrt_q15((q15_t) ((acc0) >> 17), pDst++);
		101	arm_sqrt_q15((q15_t) ((acc1) >> 17), pDst++);
		102	arm_sqrt_q15((q15_t) ((acc2) >> 17), pDst++);
		103	arm_sqrt_q15((q15_t) ((acc3) >> 17), pDst++);
		104
		105	/* Decrement the loop counter */
		106	blkCnt--;
		107	}
		108
		109	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		110	** No loop unrolling is used. */
		111	blkCnt = numSamples % 0x4u;
		112
		113	while(blkCnt > 0u)
		114	{
		115	/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
		116	in1 = *__SIMD32(pSrc)++;
		117	acc0 = __SMUAD(in1, in1);
		118
		119	/* store the result in 2.14 format in the destination buffer. */
		120	arm_sqrt_q15((q15_t) (acc0 >> 17), pDst++);
		121
		122	/* Decrement the loop counter */
		123	blkCnt--;
		124	}
		125
		126	#else
		127
		128	/* Run the below code for Cortex-M0 */
		129	q15_t real, imag; /* Temporary variables to hold input values */
		130
		131	while(numSamples > 0u)
		132	{
		133	/* out = sqrt(real * real + imag * imag) */
		134	real = *pSrc++;
		135	imag = *pSrc++;
		136
		137	acc0 = (real * real);
		138	acc1 = (imag * imag);
		139
		140	/* store the result in 2.14 format in the destination buffer. */
		141	arm_sqrt_q15((q15_t) (((q63_t) acc0 + acc1) >> 17), pDst++);
		142
		143	/* Decrement the loop counter */
		144	numSamples--;
		145	}
		146
		147	#endif /* #ifndef ARM_MATH_CM0_FAMILY */
		148
		149	}
		150
		151	/**
		152	* @} end of cmplx_mag group
		153	*/

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(root)/trunk/Drivers/CMSIS/DSP_Lib/Source/ComplexMathFunctions/arm_cmplx_mag_q15.c – Rev 2