174 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			174 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* ----------------------------------------------------------------------
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|  * Project:      CMSIS DSP Library
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|  * Title:        arm_cmplx_mag_q31.c
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|  * Description:  Q31 complex magnitude
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|  *
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|  * $Date:        27. January 2017
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|  * $Revision:    V.1.5.1
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|  *
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|  * Target Processor: Cortex-M cores
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|  * -------------------------------------------------------------------- */
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| /*
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|  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
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|  *
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|  * SPDX-License-Identifier: Apache-2.0
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|  *
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|  * Licensed under the Apache License, Version 2.0 (the License); you may
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|  * not use this file except in compliance with the License.
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|  * You may obtain a copy of the License at
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|  *
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|  * www.apache.org/licenses/LICENSE-2.0
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|  *
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|  * Unless required by applicable law or agreed to in writing, software
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|  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
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|  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|  * See the License for the specific language governing permissions and
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|  * limitations under the License.
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|  */
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| 
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| #include "arm_math.h"
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| 
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| /**
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|  * @ingroup groupCmplxMath
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|  */
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| 
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| /**
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|  * @addtogroup cmplx_mag
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|  * @{
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|  */
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| 
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| /**
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|  * @brief  Q31 complex magnitude
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|  * @param  *pSrc points to the complex input vector
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|  * @param  *pDst points to the real output vector
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|  * @param  numSamples number of complex samples in the input vector
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|  * @return none.
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|  *
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|  * <b>Scaling and Overflow Behavior:</b>
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|  * \par
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|  * The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format.
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|  * Input down scaling is not required.
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|  */
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| 
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| void arm_cmplx_mag_q31(
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|   q31_t * pSrc,
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|   q31_t * pDst,
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|   uint32_t numSamples)
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| {
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|   q31_t real, imag;                              /* Temporary variables to hold input values */
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|   q31_t acc0, acc1;                              /* Accumulators */
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|   uint32_t blkCnt;                               /* loop counter */
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| 
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| #if defined (ARM_MATH_DSP)
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| 
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|   /* Run the below code for Cortex-M4 and Cortex-M3 */
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|   q31_t real1, real2, imag1, imag2;              /* Temporary variables to hold input values */
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|   q31_t out1, out2, out3, out4;                  /* Accumulators */
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|   q63_t mul1, mul2, mul3, mul4;                  /* Temporary variables */
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| 
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| 
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|   /*loop Unrolling */
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|   blkCnt = numSamples >> 2U;
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| 
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|   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
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|    ** a second loop below computes the remaining 1 to 3 samples. */
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|   while (blkCnt > 0U)
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|   {
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|     /* read complex input from source buffer */
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|     real1 = pSrc[0];
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|     imag1 = pSrc[1];
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|     real2 = pSrc[2];
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|     imag2 = pSrc[3];
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| 
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|     /* calculate power of input values */
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|     mul1 = (q63_t) real1 *real1;
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|     mul2 = (q63_t) imag1 *imag1;
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|     mul3 = (q63_t) real2 *real2;
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|     mul4 = (q63_t) imag2 *imag2;
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| 
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|     /* get the result to 3.29 format */
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|     out1 = (q31_t) (mul1 >> 33);
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|     out2 = (q31_t) (mul2 >> 33);
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|     out3 = (q31_t) (mul3 >> 33);
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|     out4 = (q31_t) (mul4 >> 33);
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| 
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|     /* add real and imaginary accumulators */
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|     out1 = out1 + out2;
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|     out3 = out3 + out4;
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| 
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|     /* read complex input from source buffer */
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|     real1 = pSrc[4];
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|     imag1 = pSrc[5];
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|     real2 = pSrc[6];
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|     imag2 = pSrc[7];
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| 
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|     /* calculate square root */
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|     arm_sqrt_q31(out1, &pDst[0]);
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| 
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|     /* calculate power of input values */
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|     mul1 = (q63_t) real1 *real1;
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| 
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|     /* calculate square root */
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|     arm_sqrt_q31(out3, &pDst[1]);
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| 
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|     /* calculate power of input values */
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|     mul2 = (q63_t) imag1 *imag1;
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|     mul3 = (q63_t) real2 *real2;
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|     mul4 = (q63_t) imag2 *imag2;
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| 
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|     /* get the result to 3.29 format */
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|     out1 = (q31_t) (mul1 >> 33);
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|     out2 = (q31_t) (mul2 >> 33);
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|     out3 = (q31_t) (mul3 >> 33);
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|     out4 = (q31_t) (mul4 >> 33);
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| 
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|     /* add real and imaginary accumulators */
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|     out1 = out1 + out2;
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|     out3 = out3 + out4;
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| 
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|     /* calculate square root */
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|     arm_sqrt_q31(out1, &pDst[2]);
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| 
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|     /* increment destination by 8 to process next samples */
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|     pSrc += 8U;
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| 
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|     /* calculate square root */
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|     arm_sqrt_q31(out3, &pDst[3]);
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| 
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|     /* increment destination by 4 to process next samples */
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|     pDst += 4U;
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| 
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|     /* Decrement the loop counter */
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|     blkCnt--;
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|   }
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| 
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|   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
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|    ** No loop unrolling is used. */
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|   blkCnt = numSamples % 0x4U;
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| 
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| #else
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| 
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|   /* Run the below code for Cortex-M0 */
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|   blkCnt = numSamples;
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| 
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| #endif /* #if defined (ARM_MATH_DSP) */
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| 
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|   while (blkCnt > 0U)
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|   {
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|     /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
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|     real = *pSrc++;
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|     imag = *pSrc++;
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|     acc0 = (q31_t) (((q63_t) real * real) >> 33);
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|     acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
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|     /* store the result in 2.30 format in the destination buffer. */
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|     arm_sqrt_q31(acc0 + acc1, pDst++);
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| 
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|     /* Decrement the loop counter */
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|     blkCnt--;
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|   }
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| }
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| 
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| /**
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|  * @} end of cmplx_mag group
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|  */
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