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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_conj_q31.c
		9	*
		10	* Description: Q31 complex conjugate.
		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	#include "arm_math.h"
		41
		42	/**
		43	* @ingroup groupCmplxMath
		44	*/
		45
		46	/**
		47	* @addtogroup cmplx_conj
		48	* @{
		49	*/
		50
		51	/**
		52	* @brief Q31 complex conjugate.
		53	* @param *pSrc points to the input vector
		54	* @param *pDst points to the output vector
		55	* @param numSamples number of complex samples in each vector
		56	* @return none.
		57	*
		58	* <b>Scaling and Overflow Behavior:</b>
		59	* \par
		60	* The function uses saturating arithmetic.
		61	* The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
		62	*/
		63
		64	void arm_cmplx_conj_q31(
		65	q31_t * pSrc,
		66	q31_t * pDst,
		67	uint32_t numSamples)
		68	{
		69	uint32_t blkCnt; /* loop counter */
		70	q31_t in; /* Input value */
		71
		72	#ifndef ARM_MATH_CM0_FAMILY
		73
		74	/* Run the below code for Cortex-M4 and Cortex-M3 */
		75	q31_t inR1, inR2, inR3, inR4; /* Temporary real variables */
		76	q31_t inI1, inI2, inI3, inI4; /* Temporary imaginary variables */
		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]+jC[1] = A[0]+ j (-1) A[1] */
		86	/* Calculate Complex Conjugate and then store the results in the destination buffer. */
		87	/* Saturated to 0x7fffffff if the input is -1(0x80000000) */
		88	/* read real input sample */
		89	inR1 = pSrc[0];
		90	/* store real input sample */
		91	pDst[0] = inR1;
		92
		93	/* read imaginary input sample */
		94	inI1 = pSrc[1];
		95
		96	/* read real input sample */
		97	inR2 = pSrc[2];
		98	/* store real input sample */
		99	pDst[2] = inR2;
		100
		101	/* read imaginary input sample */
		102	inI2 = pSrc[3];
		103
		104	/* negate imaginary input sample */
		105	inI1 = __QSUB(0, inI1);
		106
		107	/* read real input sample */
		108	inR3 = pSrc[4];
		109	/* store real input sample */
		110	pDst[4] = inR3;
		111
		112	/* read imaginary input sample */
		113	inI3 = pSrc[5];
		114
		115	/* negate imaginary input sample */
		116	inI2 = __QSUB(0, inI2);
		117
		118	/* read real input sample */
		119	inR4 = pSrc[6];
		120	/* store real input sample */
		121	pDst[6] = inR4;
		122
		123	/* negate imaginary input sample */
		124	inI3 = __QSUB(0, inI3);
		125
		126	/* store imaginary input sample */
		127	inI4 = pSrc[7];
		128
		129	/* store imaginary input samples */
		130	pDst[1] = inI1;
		131
		132	/* negate imaginary input sample */
		133	inI4 = __QSUB(0, inI4);
		134
		135	/* store imaginary input samples */
		136	pDst[3] = inI2;
		137
		138	/* increment source pointer by 8 to proecess next samples */
		139	pSrc += 8u;
		140
		141	/* store imaginary input samples */
		142	pDst[5] = inI3;
		143	pDst[7] = inI4;
		144
		145	/* increment destination pointer by 8 to process next samples */
		146	pDst += 8u;
		147
		148	/* Decrement the loop counter */
		149	blkCnt--;
		150	}
		151
		152	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		153	** No loop unrolling is used. */
		154	blkCnt = numSamples % 0x4u;
		155
		156	#else
		157
		158	/* Run the below code for Cortex-M0 */
		159	blkCnt = numSamples;
		160
		161
		162	#endif /* #ifndef ARM_MATH_CM0_FAMILY */
		163
		164	while(blkCnt > 0u)
		165	{
		166	/* C[0]+jC[1] = A[0]+ j (-1) A[1] */
		167	/* Calculate Complex Conjugate and then store the results in the destination buffer. */
		168	/* Saturated to 0x7fffffff if the input is -1(0x80000000) */
		169	pDst++ = pSrc++;
		170	in = *pSrc++;
		171	*pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
		172
		173	/* Decrement the loop counter */
		174	blkCnt--;
		175	}
		176	}
		177
		178	/**
		179	* @} end of cmplx_conj group
		180	*/

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(root)/trunk/Drivers/CMSIS/DSP_Lib/Source/ComplexMathFunctions/arm_cmplx_conj_q31.c – Rev 2