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src/Cortex-M4-M3/ComplexMathFunctions/arm_cmplx_mult_cmplx_q31.c@0:1014af42efd9, 2011-03-10 (annotated)

Committer:: simon
Date:: Thu Mar 10 15:07:50 2011 +0000
Revision:: 0:1014af42efd9

Who changed what in which revision?

User	Revision	Line number	New contents of line
simon	0:1014af42efd9	1	/* ----------------------------------------------------------------------
simon	0:1014af42efd9	2	* Copyright (C) 2010 ARM Limited. All rights reserved.
simon	0:1014af42efd9	3	*
simon	0:1014af42efd9	4	* $Date: 29. November 2010
simon	0:1014af42efd9	5	* $Revision: V1.0.3
simon	0:1014af42efd9	6	*
simon	0:1014af42efd9	7	* Project: CMSIS DSP Library
simon	0:1014af42efd9	8	* Title: arm_cmplx_mult_cmplx_q31.c
simon	0:1014af42efd9	9	*
simon	0:1014af42efd9	10	* Description: Q31 complex-by-complex multiplication
simon	0:1014af42efd9	11	*
simon	0:1014af42efd9	12	* Target Processor: Cortex-M4/Cortex-M3
simon	0:1014af42efd9	13	*
simon	0:1014af42efd9	14	* Version 1.0.3 2010/11/29
simon	0:1014af42efd9	15	* Re-organized the CMSIS folders and updated documentation.
simon	0:1014af42efd9	16	*
simon	0:1014af42efd9	17	* Version 1.0.2 2010/11/11
simon	0:1014af42efd9	18	* Documentation updated.
simon	0:1014af42efd9	19	*
simon	0:1014af42efd9	20	* Version 1.0.1 2010/10/05
simon	0:1014af42efd9	21	* Production release and review comments incorporated.
simon	0:1014af42efd9	22	*
simon	0:1014af42efd9	23	* Version 1.0.0 2010/09/20
simon	0:1014af42efd9	24	* Production release and review comments incorporated.
simon	0:1014af42efd9	25	* -------------------------------------------------------------------- */
simon	0:1014af42efd9	26
simon	0:1014af42efd9	27	#include "arm_math.h"
simon	0:1014af42efd9	28
simon	0:1014af42efd9	29	/**
simon	0:1014af42efd9	30	* @ingroup groupCmplxMath
simon	0:1014af42efd9	31	*/
simon	0:1014af42efd9	32
simon	0:1014af42efd9	33	/**
simon	0:1014af42efd9	34	* @addtogroup CmplxByCmplxMult
simon	0:1014af42efd9	35	* @{
simon	0:1014af42efd9	36	*/
simon	0:1014af42efd9	37
simon	0:1014af42efd9	38
simon	0:1014af42efd9	39	/**
simon	0:1014af42efd9	40	* @brief Q31 complex-by-complex multiplication
simon	0:1014af42efd9	41	* @param[in] *pSrcA points to the first input vector
simon	0:1014af42efd9	42	* @param[in] *pSrcB points to the second input vector
simon	0:1014af42efd9	43	* @param[out] *pDst points to the output vector
simon	0:1014af42efd9	44	* @param[in] numSamples number of complex samples in each vector
simon	0:1014af42efd9	45	* @return none.
simon	0:1014af42efd9	46	*
simon	0:1014af42efd9	47	* <b>Scaling and Overflow Behavior:</b>
simon	0:1014af42efd9	48	* \par
simon	0:1014af42efd9	49	* The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format.
simon	0:1014af42efd9	50	* Input down scaling is not required.
simon	0:1014af42efd9	51	*/
simon	0:1014af42efd9	52
simon	0:1014af42efd9	53	void arm_cmplx_mult_cmplx_q31(
simon	0:1014af42efd9	54	q31_t * pSrcA,
simon	0:1014af42efd9	55	q31_t * pSrcB,
simon	0:1014af42efd9	56	q31_t * pDst,
simon	0:1014af42efd9	57	uint32_t numSamples)
simon	0:1014af42efd9	58	{
simon	0:1014af42efd9	59	q31_t a, b, c, d; /* Temporary variables to store real and imaginary values */
simon	0:1014af42efd9	60	uint32_t blkCnt; /* loop counters */
simon	0:1014af42efd9	61
simon	0:1014af42efd9	62	/* loop Unrolling */
simon	0:1014af42efd9	63	blkCnt = numSamples >> 2u;
simon	0:1014af42efd9	64
simon	0:1014af42efd9	65	/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
simon	0:1014af42efd9	66	** a second loop below computes the remaining 1 to 3 samples. */
simon	0:1014af42efd9	67	while(blkCnt > 0u)
simon	0:1014af42efd9	68	{
simon	0:1014af42efd9	69	/* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */
simon	0:1014af42efd9	70	/* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */
simon	0:1014af42efd9	71	a = *pSrcA++;
simon	0:1014af42efd9	72	b = *pSrcA++;
simon	0:1014af42efd9	73	c = *pSrcB++;
simon	0:1014af42efd9	74	d = *pSrcB++;
simon	0:1014af42efd9	75
simon	0:1014af42efd9	76	/* store the real result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	77	pDst++ = (q31_t) ((((q63_t) a c) >> 33) - (((q63_t) b * d) >> 33));
simon	0:1014af42efd9	78	/* store the imag result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	79	pDst++ = (q31_t) ((((q63_t) a d) >> 33) + (((q63_t) b * c) >> 33));
simon	0:1014af42efd9	80
simon	0:1014af42efd9	81	a = *pSrcA++;
simon	0:1014af42efd9	82	b = *pSrcA++;
simon	0:1014af42efd9	83	c = *pSrcB++;
simon	0:1014af42efd9	84	d = *pSrcB++;
simon	0:1014af42efd9	85
simon	0:1014af42efd9	86	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	87	pDst++ = (q31_t) ((((q63_t) a c) >> 33) - (((q63_t) b * d) >> 33));
simon	0:1014af42efd9	88	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	89	pDst++ = (q31_t) ((((q63_t) a d) >> 33) + (((q63_t) b * c) >> 33));
simon	0:1014af42efd9	90
simon	0:1014af42efd9	91	a = *pSrcA++;
simon	0:1014af42efd9	92	b = *pSrcA++;
simon	0:1014af42efd9	93	c = *pSrcB++;
simon	0:1014af42efd9	94	d = *pSrcB++;
simon	0:1014af42efd9	95
simon	0:1014af42efd9	96	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	97	pDst++ = (q31_t) ((((q63_t) a c) >> 33) - (((q63_t) b * d) >> 33));
simon	0:1014af42efd9	98	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	99	pDst++ = (q31_t) ((((q63_t) a d) >> 33) + (((q63_t) b * c) >> 33));
simon	0:1014af42efd9	100
simon	0:1014af42efd9	101	a = *pSrcA++;
simon	0:1014af42efd9	102	b = *pSrcA++;
simon	0:1014af42efd9	103	c = *pSrcB++;
simon	0:1014af42efd9	104	d = *pSrcB++;
simon	0:1014af42efd9	105
simon	0:1014af42efd9	106	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	107	pDst++ = (q31_t) ((((q63_t) a c) >> 33) - (((q63_t) b * d) >> 33));
simon	0:1014af42efd9	108	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	109	pDst++ = (q31_t) ((((q63_t) a d) >> 33) + (((q63_t) b * c) >> 33));
simon	0:1014af42efd9	110
simon	0:1014af42efd9	111	/* Decrement the blockSize loop counter */
simon	0:1014af42efd9	112	blkCnt--;
simon	0:1014af42efd9	113	}
simon	0:1014af42efd9	114
simon	0:1014af42efd9	115	/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
simon	0:1014af42efd9	116	** No loop unrolling is used. */
simon	0:1014af42efd9	117	blkCnt = numSamples % 0x4u;
simon	0:1014af42efd9	118
simon	0:1014af42efd9	119	while(blkCnt > 0u)
simon	0:1014af42efd9	120	{
simon	0:1014af42efd9	121	/* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */
simon	0:1014af42efd9	122	/* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */
simon	0:1014af42efd9	123	a = *pSrcA++;
simon	0:1014af42efd9	124	b = *pSrcA++;
simon	0:1014af42efd9	125	c = *pSrcB++;
simon	0:1014af42efd9	126	d = *pSrcB++;
simon	0:1014af42efd9	127
simon	0:1014af42efd9	128	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	129	pDst++ = (q31_t) ((((q63_t) a c) >> 33) - (((q63_t) b * d) >> 33));
simon	0:1014af42efd9	130	/* store the result in 3.29 format in the destination buffer. */
simon	0:1014af42efd9	131	pDst++ = (q31_t) ((((q63_t) a d) >> 33) + (((q63_t) b * c) >> 33));
simon	0:1014af42efd9	132
simon	0:1014af42efd9	133	/* Decrement the blockSize loop counter */
simon	0:1014af42efd9	134	blkCnt--;
simon	0:1014af42efd9	135	}
simon	0:1014af42efd9	136	}
simon	0:1014af42efd9	137
simon	0:1014af42efd9	138	/**
simon	0:1014af42efd9	139	* @} end of CmplxByCmplxMult group
simon	0:1014af42efd9	140	*/

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Type:	Library
Created:	10 Mar 2011
Imports:	907
Forks:	1
Commits:	3
Dependents:	5
Dependencies:	0
Followers:	35

src/Cortex-M4-M3/ComplexMathFunctions/arm_cmplx_mult_cmplx_q31.c@0:1014af42efd9, 2011-03-10 (annotated)

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