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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_mult_real_q31.c
		9	*
		10	* Description: Q31 complex by real multiplication
		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 CmplxByRealMult
		49	* @{
		50	*/
		51
		52
		53	/**
		54	* @brief Q31 complex-by-real multiplication
		55	* @param[in] *pSrcCmplx points to the complex input vector
		56	* @param[in] *pSrcReal points to the real input vector
		57	* @param[out] *pCmplxDst points to the complex output vector
		58	* @param[in] numSamples number of samples in each vector
		59	* @return none.
		60	*
		61	* <b>Scaling and Overflow Behavior:</b>
		62	* \par
		63	* The function uses saturating arithmetic.
		64	* Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] will be saturated.
		65	*/
		66
		67	void arm_cmplx_mult_real_q31(
		68	q31_t * pSrcCmplx,
		69	q31_t * pSrcReal,
		70	q31_t * pCmplxDst,
		71	uint32_t numSamples)
		72	{
		73	q31_t inA1; /* Temporary variable to store input value */
		74
		75	#ifndef ARM_MATH_CM0_FAMILY
		76
		77	/* Run the below code for Cortex-M4 and Cortex-M3 */
		78	uint32_t blkCnt; /* loop counters */
		79	q31_t inA2, inA3, inA4; /* Temporary variables to hold input data */
		80	q31_t inB1, inB2; /* Temporary variabels to hold input data */
		81	q31_t out1, out2, out3, out4; /* Temporary variables to hold output data */
		82
		83	/* loop Unrolling */
		84	blkCnt = numSamples >> 2u;
		85
		86	/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
		87	** a second loop below computes the remaining 1 to 3 samples. */
		88	while(blkCnt > 0u)
		89	{
		90	/* C[2 * i] = A[2 * i] * B[i]. */
		91	/* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
		92	/* read real input from complex input buffer */
		93	inA1 = *pSrcCmplx++;
		94	inA2 = *pSrcCmplx++;
		95	/* read input from real input bufer */
		96	inB1 = *pSrcReal++;
		97	inB2 = *pSrcReal++;
		98	/* read imaginary input from complex input buffer */
		99	inA3 = *pSrcCmplx++;
		100	inA4 = *pSrcCmplx++;
		101
		102	/* multiply complex input with real input */
		103	out1 = ((q63_t) inA1 * inB1) >> 32;
		104	out2 = ((q63_t) inA2 * inB1) >> 32;
		105	out3 = ((q63_t) inA3 * inB2) >> 32;
		106	out4 = ((q63_t) inA4 * inB2) >> 32;
		107
		108	/* sature the result */
		109	out1 = __SSAT(out1, 31);
		110	out2 = __SSAT(out2, 31);
		111	out3 = __SSAT(out3, 31);
		112	out4 = __SSAT(out4, 31);
		113
		114	/* get result in 1.31 format */
		115	out1 = out1 << 1;
		116	out2 = out2 << 1;
		117	out3 = out3 << 1;
		118	out4 = out4 << 1;
		119
		120	/* store the result to destination buffer */
		121	*pCmplxDst++ = out1;
		122	*pCmplxDst++ = out2;
		123	*pCmplxDst++ = out3;
		124	*pCmplxDst++ = out4;
		125
		126	/* read real input from complex input buffer */
		127	inA1 = *pSrcCmplx++;
		128	inA2 = *pSrcCmplx++;
		129	/* read input from real input bufer */
		130	inB1 = *pSrcReal++;
		131	inB2 = *pSrcReal++;
		132	/* read imaginary input from complex input buffer */
		133	inA3 = *pSrcCmplx++;
		134	inA4 = *pSrcCmplx++;
		135
		136	/* multiply complex input with real input */
		137	out1 = ((q63_t) inA1 * inB1) >> 32;
		138	out2 = ((q63_t) inA2 * inB1) >> 32;
		139	out3 = ((q63_t) inA3 * inB2) >> 32;
		140	out4 = ((q63_t) inA4 * inB2) >> 32;
		141
		142	/* sature the result */
		143	out1 = __SSAT(out1, 31);
		144	out2 = __SSAT(out2, 31);
		145	out3 = __SSAT(out3, 31);
		146	out4 = __SSAT(out4, 31);
		147
		148	/* get result in 1.31 format */
		149	out1 = out1 << 1;
		150	out2 = out2 << 1;
		151	out3 = out3 << 1;
		152	out4 = out4 << 1;
		153
		154	/* store the result to destination buffer */
		155	*pCmplxDst++ = out1;
		156	*pCmplxDst++ = out2;
		157	*pCmplxDst++ = out3;
		158	*pCmplxDst++ = out4;
		159
		160	/* Decrement the numSamples loop counter */
		161	blkCnt--;
		162	}
		163
		164	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		165	** No loop unrolling is used. */
		166	blkCnt = numSamples % 0x4u;
		167
		168	while(blkCnt > 0u)
		169	{
		170	/* C[2 * i] = A[2 * i] * B[i]. */
		171	/* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
		172	/* read real input from complex input buffer */
		173	inA1 = *pSrcCmplx++;
		174	inA2 = *pSrcCmplx++;
		175	/* read input from real input bufer */
		176	inB1 = *pSrcReal++;
		177
		178	/* multiply complex input with real input */
		179	out1 = ((q63_t) inA1 * inB1) >> 32;
		180	out2 = ((q63_t) inA2 * inB1) >> 32;
		181
		182	/* sature the result */
		183	out1 = __SSAT(out1, 31);
		184	out2 = __SSAT(out2, 31);
		185
		186	/* get result in 1.31 format */
		187	out1 = out1 << 1;
		188	out2 = out2 << 1;
		189
		190	/* store the result to destination buffer */
		191	*pCmplxDst++ = out1;
		192	*pCmplxDst++ = out2;
		193
		194	/* Decrement the numSamples loop counter */
		195	blkCnt--;
		196	}
		197
		198	#else
		199
		200	/* Run the below code for Cortex-M0 */
		201
		202	while(numSamples > 0u)
		203	{
		204	/* realOut = realA * realB. */
		205	/* imagReal = imagA * realB. */
		206	inA1 = *pSrcReal++;
		207	/* store the result in the destination buffer. */
		208	*pCmplxDst++ =
		209	(q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * inA1) >> 31);
		210	*pCmplxDst++ =
		211	(q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * inA1) >> 31);
		212
		213	/* Decrement the numSamples loop counter */
		214	numSamples--;
		215	}
		216
		217	#endif /* #ifndef ARM_MATH_CM0_FAMILY */
		218
		219	}
		220
		221	/**
		222	* @} end of CmplxByRealMult group
		223	*/

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