150 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			150 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* ----------------------------------------------------------------------
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|  * Project:      CMSIS DSP Library
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|  * Title:        arm_cmplx_conj_q15.c
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|  * Description:  Q15 complex conjugate
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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_conj
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|  * @{
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|  */
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| 
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| /**
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|  * @brief  Q15 complex conjugate.
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|  * @param  *pSrc points to the input vector
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|  * @param  *pDst points to the output vector
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|  * @param  numSamples number of complex samples in each 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 uses saturating arithmetic.
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|  * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
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|  */
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| 
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| void arm_cmplx_conj_q15(
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|   q15_t * pSrc,
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|   q15_t * pDst,
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|   uint32_t numSamples)
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| {
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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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|   uint32_t blkCnt;                               /* loop counter */
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|   q31_t in1, in2, in3, in4;
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|   q31_t zero = 0;
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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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|     /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
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|     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
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|     in1 = *__SIMD32(pSrc)++;
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|     in2 = *__SIMD32(pSrc)++;
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|     in3 = *__SIMD32(pSrc)++;
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|     in4 = *__SIMD32(pSrc)++;
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| 
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| #ifndef ARM_MATH_BIG_ENDIAN
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| 
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|     in1 = __QASX(zero, in1);
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|     in2 = __QASX(zero, in2);
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|     in3 = __QASX(zero, in3);
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|     in4 = __QASX(zero, in4);
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| 
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| #else
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| 
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|     in1 = __QSAX(zero, in1);
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|     in2 = __QSAX(zero, in2);
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|     in3 = __QSAX(zero, in3);
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|     in4 = __QSAX(zero, in4);
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| 
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| #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
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| 
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|     in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16);
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|     in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16);
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|     in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16);
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|     in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16);
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| 
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|     *__SIMD32(pDst)++ = in1;
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|     *__SIMD32(pDst)++ = in2;
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|     *__SIMD32(pDst)++ = in3;
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|     *__SIMD32(pDst)++ = in4;
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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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|   while (blkCnt > 0U)
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|   {
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|     /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
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|     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
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|     *pDst++ = *pSrc++;
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|     *pDst++ = __SSAT(-*pSrc++, 16);
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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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| #else
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| 
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|   q15_t in;
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| 
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|   /* Run the below code for Cortex-M0 */
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| 
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|   while (numSamples > 0U)
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|   {
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|     /* realOut + j (imagOut) = realIn+ j (-1) imagIn */
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|     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
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|     *pDst++ = *pSrc++;
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|     in = *pSrc++;
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|     *pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;
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| 
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|     /* Decrement the loop counter */
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|     numSamples--;
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|   }
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| 
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| #endif /* #if defined (ARM_MATH_DSP) */
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| 
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| }
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| 
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| /**
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|  * @} end of cmplx_conj group
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|  */
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