WebSVN – dashGPS – Blame – /branches/dashGPS-bmp/Drivers/CMSIS/DSP/Source/ComplexMathFunctions/arm_cmplx_mag_f32.c

Rev	Author	Line No.	Line
2	mjames	1	/* ----------------------------------------------------------------------
		2	* Project: CMSIS DSP Library
		3	* Title: arm_cmplx_mag_f32.c
		4	* Description: Floating-point complex magnitude
		5	*
		6	* $Date: 27. January 2017
		7	* $Revision: V.1.5.1
		8	*
		9	* Target Processor: Cortex-M cores
		10	* -------------------------------------------------------------------- */
		11	/*
		12	* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
		13	*
		14	* SPDX-License-Identifier: Apache-2.0
		15	*
		16	* Licensed under the Apache License, Version 2.0 (the License); you may
		17	* not use this file except in compliance with the License.
		18	* You may obtain a copy of the License at
		19	*
		20	* www.apache.org/licenses/LICENSE-2.0
		21	*
		22	* Unless required by applicable law or agreed to in writing, software
		23	* distributed under the License is distributed on an AS IS BASIS, WITHOUT
		24	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		25	* See the License for the specific language governing permissions and
		26	* limitations under the License.
		27	*/
		28
		29	#include "arm_math.h"
		30
		31	/**
		32	* @ingroup groupCmplxMath
		33	*/
		34
		35	/**
		36	* @defgroup cmplx_mag Complex Magnitude
		37	*
		38	* Computes the magnitude of the elements of a complex data vector.
		39	*
		40	* The <code>pSrc</code> points to the source data and
		41	* <code>pDst</code> points to the where the result should be written.
		42	* <code>numSamples</code> specifies the number of complex samples
		43	* in the input array and the data is stored in an interleaved fashion
		44	* (real, imag, real, imag, ...).
		45	* The input array has a total of <code>2*numSamples</code> values;
		46	* the output array has a total of <code>numSamples</code> values.
		47	* The underlying algorithm is used:
		48	*
		49	* <pre>
		50	* for(n=0; n<numSamples; n++) {
		51	* pDst[n] = sqrt(pSrc[(2n)+0]^2 + pSrc[(2n)+1]^2);
		52	* }
		53	* </pre>
		54	*
		55	* There are separate functions for floating-point, Q15, and Q31 data types.
		56	*/
		57
		58	/**
		59	* @addtogroup cmplx_mag
		60	* @{
		61	*/
		62	/**
		63	* @brief Floating-point complex magnitude.
		64	* @param[in] *pSrc points to complex input buffer
		65	* @param[out] *pDst points to real output buffer
		66	* @param[in] numSamples number of complex samples in the input vector
		67	* @return none.
		68	*
		69	*/
		70
		71
		72	void arm_cmplx_mag_f32(
		73	float32_t * pSrc,
		74	float32_t * pDst,
		75	uint32_t numSamples)
		76	{
		77	float32_t realIn, imagIn; /* Temporary variables to hold input values */
		78
		79	#if defined (ARM_MATH_DSP)
		80
		81	/* Run the below code for Cortex-M4 and Cortex-M3 */
		82	uint32_t blkCnt; /* loop counter */
		83
		84	/loop Unrolling /
		85	blkCnt = numSamples >> 2U;
		86
		87	/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
		88	** a second loop below computes the remaining 1 to 3 samples. */
		89	while (blkCnt > 0U)
		90	{
		91
		92	/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
		93	realIn = *pSrc++;
		94	imagIn = *pSrc++;
		95	/* store the result in the destination buffer. */
		96	arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
		97
		98	realIn = *pSrc++;
		99	imagIn = *pSrc++;
		100	arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
		101
		102	realIn = *pSrc++;
		103	imagIn = *pSrc++;
		104	arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
		105
		106	realIn = *pSrc++;
		107	imagIn = *pSrc++;
		108	arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
		109
		110
		111	/* Decrement the loop counter */
		112	blkCnt--;
		113	}
		114
		115	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		116	** No loop unrolling is used. */
		117	blkCnt = numSamples % 0x4U;
		118
		119	while (blkCnt > 0U)
		120	{
		121	/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
		122	realIn = *pSrc++;
		123	imagIn = *pSrc++;
		124	/* store the result in the destination buffer. */
		125	arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
		126
		127	/* Decrement the loop counter */
		128	blkCnt--;
		129	}
		130
		131	#else
		132
		133	/* Run the below code for Cortex-M0 */
		134
		135	while (numSamples > 0U)
		136	{
		137	/* out = sqrt((real * real) + (imag * imag)) */
		138	realIn = *pSrc++;
		139	imagIn = *pSrc++;
		140	/* store the result in the destination buffer. */
		141	arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
		142
		143	/* Decrement the loop counter */
		144	numSamples--;
		145	}
		146
		147	#endif /* #if defined (ARM_MATH_DSP) */
		148
		149	}
		150
		151	/**
		152	* @} end of cmplx_mag group
		153	*/

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(root)/branches/dashGPS-bmp/Drivers/CMSIS/DSP/Source/ComplexMathFunctions/arm_cmplx_mag_f32.c – Rev 18