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  1. /* ----------------------------------------------------------------------    
  2. * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  3. *    
  4. * $Date:        19. October 2015
  5. * $Revision:    V.1.4.5 a
  6. *    
  7. * Project:          CMSIS DSP Library    
  8. * Title:                arm_cmplx_conj_q15.c    
  9. *    
  10. * Description:  Q15 complex conjugate.    
  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 cmplx_conj    
  49.  * @{    
  50.  */
  51.  
  52. /**    
  53.  * @brief  Q15 complex conjugate.    
  54.  * @param  *pSrc points to the input vector    
  55.  * @param  *pDst points to the output vector    
  56.  * @param  numSamples number of complex samples in each vector    
  57.  * @return none.    
  58.  *    
  59.  * <b>Scaling and Overflow Behavior:</b>    
  60.  * \par    
  61.  * The function uses saturating arithmetic.    
  62.  * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.    
  63.  */
  64.  
  65. void arm_cmplx_conj_q15(
  66.   q15_t * pSrc,
  67.   q15_t * pDst,
  68.   uint32_t numSamples)
  69. {
  70.  
  71. #ifndef ARM_MATH_CM0_FAMILY
  72.  
  73.   /* Run the below code for Cortex-M4 and Cortex-M3 */
  74.   uint32_t blkCnt;                               /* loop counter */
  75.   q31_t in1, in2, in3, in4;
  76.   q31_t zero = 0;
  77.  
  78.   /*loop Unrolling */
  79.   blkCnt = numSamples >> 2u;
  80.  
  81.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
  82.    ** a second loop below computes the remaining 1 to 3 samples. */
  83.   while(blkCnt > 0u)
  84.   {
  85.     /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
  86.     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
  87.     in1 = *__SIMD32(pSrc)++;
  88.     in2 = *__SIMD32(pSrc)++;
  89.     in3 = *__SIMD32(pSrc)++;
  90.     in4 = *__SIMD32(pSrc)++;
  91.  
  92. #ifndef ARM_MATH_BIG_ENDIAN
  93.  
  94.     in1 = __QASX(zero, in1);
  95.     in2 = __QASX(zero, in2);
  96.     in3 = __QASX(zero, in3);
  97.     in4 = __QASX(zero, in4);
  98.  
  99. #else
  100.  
  101.     in1 = __QSAX(zero, in1);
  102.     in2 = __QSAX(zero, in2);
  103.     in3 = __QSAX(zero, in3);
  104.     in4 = __QSAX(zero, in4);
  105.  
  106. #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
  107.  
  108.     in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16);
  109.     in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16);
  110.     in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16);
  111.     in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16);
  112.  
  113.     *__SIMD32(pDst)++ = in1;
  114.     *__SIMD32(pDst)++ = in2;
  115.     *__SIMD32(pDst)++ = in3;
  116.     *__SIMD32(pDst)++ = in4;
  117.  
  118.     /* Decrement the loop counter */
  119.     blkCnt--;
  120.   }
  121.  
  122.   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.    
  123.    ** No loop unrolling is used. */
  124.   blkCnt = numSamples % 0x4u;
  125.  
  126.   while(blkCnt > 0u)
  127.   {
  128.     /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
  129.     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
  130.     *pDst++ = *pSrc++;
  131.     *pDst++ = __SSAT(-*pSrc++, 16);
  132.  
  133.     /* Decrement the loop counter */
  134.     blkCnt--;
  135.   }
  136.  
  137. #else
  138.  
  139.   q15_t in;
  140.  
  141.   /* Run the below code for Cortex-M0 */
  142.  
  143.   while(numSamples > 0u)
  144.   {
  145.     /* realOut + j (imagOut) = realIn+ j (-1) imagIn */
  146.     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
  147.     *pDst++ = *pSrc++;
  148.     in = *pSrc++;
  149.     *pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;
  150.  
  151.     /* Decrement the loop counter */
  152.     numSamples--;
  153.   }
  154.  
  155. #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  156.  
  157. }
  158.  
  159. /**    
  160.  * @} end of cmplx_conj group    
  161.  */
  162.